Chapter 3_2010_Allocating Resources Over Time
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翻译原文In the $CATALINA_HOME/conf/server.xml configuration file, within the scope of the localhost <Host> component, add the following <DefaultContext> element:<DefaultContext><Resource name=‖jdbc/WroxTC5‖ auth=‖Container‖type=‖javax.sql.DataSource‖/><ResourceParams name=‖jdbc/WroxTC5‖><parameter><name>driverClassName</name><value>com.mysql.jdbc.Driver</value></parameter><parameter><name>url</name><value>jdbc:mysql://localhost/wroxtomcat</value></parameter><parameter><name>username</name><value>empro</value></parameter><parameter><name>password</name><value>empass</value></parameter><parameter><name>maxActive</name><value>20</value></parameter><parameter><name>maxIdle</name><value>30000</value></parameter><parameter><name>maxWait</name><value>100</value></parameter></ResourceParams></DefaultContext>The urlparameter is often named driverNamein old documentation for legacy reasons (older version name), and can still be specified using the old name. For all new work, use url.This configuration will work fine with Tomcat 5 or 4, as they both use DBCP connection pooling.Two optional parameters (removeAbandoned and removeAbandonedTimout) help with the recycling of database connections, even for those that may not be released properly because of faulty developer coding.When the number of available connections in the pool runs low, the DBCP pool management code will recycle connections based on an elapsed idle timeout. For example, the following additional parameterswill cause the DBCP pool management code to recycle all JDBC connections that are idled for more than 15 minutes:<parameter><name>removeAbandoned</name><value>true</value></parameter><parameter><name>removeAbandonedTimeout</name><value>15</value></parameter>If you are running an older Tomcat release that uses the Tyrex (licensed) data-source factory by default (Tomcat 4.0.4 or later up to 4.1.3), you will need to add the following parameter to the <ResourceParams> element:<ResourceParams name=‖jdbc/WroxTC5‖><parameter><name>factory</name><value>mons.dbcp.BasicDataSourceFactory</value></parameter>...In addition, because Tomcat 5 includes the required Jakarta Commons libraries by default, you will find the DBCP and dependent libraries in the$CATALINA_HOME/common/lib directory. These binaries include the following:❑ commons-dbcp-1.1.jar❑ commons-collection.jar❑ commons-pool-1.1.jarTomcat 4 also already uses the DBCP library code by default since the release of Tomcat 4.1.3. If you are using versions prior to 4.1.3, you will need to download the aforementioned JAR files from the JakartaCommons site at the following URL and copy them into the directory manually: /commons/index.htmlStep 2—Add the <resource-ref/> entries to web.xmlInstead of creating a new Web application, an easy way to add a test JSP is by adding it to an existing example application from Tomcat. To do this, change directory to $CATALINA_HOME/webapps/jsp-examples/WEB-INF and edit the web.xml file (this is the deployment descriptor of the jsp-examples Web application). Add the following highlighted code to web.xml (note that it should be added immediately after the last<env-entry> element in the file):...<env-entry><env-entry-name>foo/name4</env-entry-name><env-entry-type>ng.Integer</env-entry-type><env-entry-value>10</env-entry-value></env-entry><resource-ref><res-ref-name>jdbc/WroxTC5</res-ref-name><res-type>javax.sql.DataSource</res-type><res-auth>Container</res-auth></resource-ref>This <resource-ref> entry makes the jdbc/WroxTC5 context, via JNDI APIs, available within the jsp-examples Web application.Step 3—Use JNDI to look up a data sourceFinally, it is time to write the code that will look up the data source and start querying the database. The followingJSP, JDBCTest.jsp, will do exactly this. Put it into a$CATALINA_HOME/webapps/jsp-examples/wroxjdbc directory (create this directory yourself). Pay special attention to the way JNDI is used to obtain the data source (code highlighted).<html><head><%@ page errorPage=‖errorpg.jsp‖import=‖java.sql.*,javax.sql.*,java.io.*,javax.naming.InitialContext,javax.naming.Context‖ %></head><body><h1>JDBC JNDI Resource Test</h1><%InitialContext initCtx = new InitialContext();DataSource ds = (DataSource)initCtx.lookup(―java:comp/env/jdbc/WroxTC5‖);Connection conn = ds.getConnection();Statement stmt = conn.createStatement();ResultSet rset = stmt.executeQuery(―select * from employee;‖);%><table width=’600’ border=’1’><tr><th align=’left’>Employee ID</th><th align=’left’>Name</th><th align=’left’>Department</th></tr><%while (rset.next()) {%><tr><td><%= rset.getString(1) %></td><td><%= rset.getString(2) %></td><td><%= rset.getString(4) %></td></tr><% }rset.close();stmt.close();conn.close();initCtx.close();%></table></body></html>The JNDI code highlighted here first obtains the InitialContext from Tomcat. It then uses this context to look up the JNDI resource that we have configured. Note that all Tomcat JNDI resources are found relative to java:comp/env/. Once the data source isobtained through JNDI, it is used to create a connection (actually pooled through DBCP). The JSP then performs a SELECT * on the employee table,and prints out all the rows that are retrieved. Finally, it creates an HTML table containing all the table rows.Any exception caught during execution of this JSP is redirected to a very simpleerror-handling page called the errorpg.jsp file. This file is specified via the errorPage attribute of the @page directive.Here is the content of errorpg.jsp:<html><body><%@ page isErrorPage=‖true‖ %><h1> An error has occurred </h1><%= exception.getMessage() %></body></html>This page will simply display a message indicating the exception caught.Testing the JNDI Resource ConfigurationAt this point, the JNDI resources are prepared, the database tables are populated, the<resource-ref>to the deployment descriptor has been added, and a JSP that will use JNDI to obtain a JDBC data sourcehas been created. It is time to give the new JSP code a test.Start Tomcat 5 and then, from a browser, attempt to reach the following URL:http://localhost:8080/jsp-examples/wroxjdbc/JDBCTest.jspThis will compile and execute the JSP code. If everything is configured correctly and working, your browser display should be similar to what is shown in Figure 14-4.The Web page shown in Figure 14-4 is the result of a JDBC query to the MySQL database data, via a connection obtained from the JNDI lookup.You may face exceptions such as the server denying access to the data source, or some server connection failures, which are caused by the MySQL user account not having enough privileges.Alternative JDBC ConfigurationIn Tomcat 5, the JNDI API is the preferred and recommended way to pass a JDBC data source to yourWeb applications. It is currently the best-supported mechanism to access JDBC data sources.However, in production, you might encounter situations in which you have to consider alternative means of JDBC data source or connection access.Typically, there is no reason why newly developed database access code slated for Web application deployment should not use the preferred JNDI mechanism for data access. However, because JDBC 1 was a widely used and highly functional API long before the arrival of JDBC 2 and JDBC 3, a largelegacy base of working JDBC code remains unaware of data sources and connectionpooling.There may be circumstances in which you must integrate legacy code, and the source code is either not available or cannot be changed. Typically, legacy JDBC 1 code has both the JDBC driver and the URL of the database hard-coded. Thankfully, JDBC 2 and JDBC 3 continue to maintain backward compatibility with JDBC 1. This means that legacy code can continue to run, even in Tomcat 5 servers.Another potential reason for deviating from the recommended configuration is the deployment of an alternative connection pool manager. This could happen, for example, with a shared hosting ISP using a commercial product that does not support the Jakarta Commons DBCP pooling. In addition, developers sometimes disagree about the merits of one pool manager implementation over another.Alternative Connection Pool ManagersUp until Tomcat 4.1.x, connection-pooling implementation on Tomcat servers has evolved in a roll-yourown manner. Because Tomcat did not provide default support, anyone who needed the functionality (which included anyone who deployed any large- or medium-scale Web application) had to write theirown code, or find a third-party solution to the problem.As a result, it is quite likely that some legacy projects on Tomcat are using an alternative connectionpooling manager, with its own requirements for data-source configuration.The following section examines one such pool manager, and shows how its configuration and access differ from the preferred method. The alternate pool manager is PoolMan (Pool Manager). It is an opensource project that is hosted on Source Forge at the following URL:/projects/poolman/About PoolManSince well before the introduction of DBCP, the open-source PoolMan has provided flexible object pooling for developers. PoolMan provides a generic pooling mechanism for Java language objects, with specialized focus on JDBC connections. PoolMan 2.0 (the latest version available as of this writing) provides the following features:❑ Flexible pool configuration across server instance, Web application, or other boundaries❑ Support for multiple pools operating concurrently❑ Timeout-based automatic connection recovery (this feature has been recently implemented inDBCP)❑ API-based programmatic access to all pools and pooled resources❑ Managed cached SQL queries❑ JMX-based run-time management❑ Support for JDBC 2 and 3 style drivers, and provision of multiple ways to integrate with applications or serversSome of the these features may be attractive to developers, and may indeed be the reason why PoolMan is deployed in specific production scenarios.The choice of one pool management strategy over another is highly dependent on the application, the system configuration, the data-access pattern, and subjectivedesigner/developer preferences.Deploying PoolManThe PoolMan binary is packaged as a single JAR file, called poolman.jar. The placement of this library will depend on your specific pool-management strategy. For example, if you were to pool JDBC connections on a per-Web-application basis, the poolman.jar file should be placed under theWEB-INF/lib directory of your Web application. The following example assumes that you will be usingPoolMan to manage server-wide pool(s) of JDBC connections. In this case, poolman.jar must be copied into the %CATALINA_HOME%/common/lib directory.When using JDK 1.4 with Tomcat 5, simply copying poolman.jar to common/lib is sufficient. This is because XML parser support and JDBC 2+ libraries are standard with JDK 1.4. If you are using JDK 1.3, however, you must add the dependent libraries manually. These libraries are included with the PoolMan code download and include thefollowing:❑ xerces.jar❑ jta.jar❑ jdbc2_0-stdext.jarPoolMan supports its own XML-based configuration file. The configuration of the JDBC driver,Connector/J for MySQL in this case, must be performed within PoolMan’s configuration file.PoolMan’s XML Configuration FileIt is of utmost importance for PoolMa PoolMan’s XML Configuration Filen to find its configuration file (called poolman.xml). Otherwise,you may encounter strange run-time errors. To locate the poolman.xml configuration file, PoolMan looks at the system classpath (essentially, the CLASSPATH environment when the JVM is started). The best way to ensure that the poolman.xml file will be loaded is as follows:1. Create a c:\home\poolman directory in which to place the poolman.xml file.2. Include the path c:\home\poolman inthe %CATALINA_HOME%\bin\setclasspath.bat(or setclasspath.sh for Linux/Unix) file.In this case, the addition of the path into setclasspath.bat is used:...rem Set standard CLASSPATHrem Note that there are no quotes as we do not want to introduce randomrem quotes into the CLASSPATHset CLASSPATH=%JAVA_HOME%\lib\tools.jar;c:\home\poolmanrem Set standard command for invoking Java.The content of the poolman.xml file provides instructions for PoolMan to access the MySQL database.The configuration parameters are similar to those of DBCP. The following is a listing ofthe poolman.xml configuration used:<xml version=‖1.0‖ encoding=‖UTF-8‖?><poolman><management-mode>local</management-mode><datasource><dbname>wroxtomcat</dbname><jndiName>mysqlsrc</jndiName><driver>com.mysql.jdbc.Driver</driver><url>jdbc:mysql://localhost/wroxtomcat</url><username>empro</username><password>empass</password><minimumSize>0</minimumSize><maximumSize>10</maximumSize><connectionTimeout>600</connectionTimeout><userTimeout>12</userTimeout></datasource></poolman>The following table provides a brief description of the elements in this configuration file. For a more detailed description of the elements and allowed values, consult the PoolMan documentation.Configuration Element Descriptionpoolman Must be the outermost element (XML documentelement) of the XML configuration file management-mode Can be local or jmx. Local mode is started without JMX support.datasource Describes a pool of JDBC connections. Each<datsource>element describes one pool of JDBC connections.dbname The name for the pool of JDBC connections jndiname The name used in the JNDI lookup context to locatethe pool of JDBC connectionsdriver The Java language class name of the JDBC driver to useurl The URL passed to the driver to access the RDBMS for connections in this poolusername The login name for accessing the RDBMS password The password for accessing the RDBMS minimumSize The smallest number of connections in the pool maximumSize The maximum number of connections allowed in the poolconnectionTimeout The number of seconds to hold a connection in the poolbeforeclosing it. A value of 600 is for 10 minutes.Configuration Element DescriptionuserTimeout The number of seconds before a JDBC connectionclaimed by a user is placed back into the pool. Thisis used to reclaim user connections in case user codeforgets to give them back. Here,12 seconds is morethan adequate for the short queries that youperform.Note that the userTimeout parameter inPoolMan is directly analogous to the newremoveAbandonTimeout parameter in Tomcat 5’sDBCP pool manager.Obtaining JDBC Connections Without JNDI LookupPoolMan has a rich heritage that includes support of connection pooling back in the days of JDBC 1,before JDBC 2 became popular. In those times, it was necessary to hard-code the JDBC driver instantiationand connection establishment right into the JSP. To illustrate how different such an approach may look, this first example uses the JDBC 1 method to obtain the JDBCconnection. The JSP that you createis placed in the %CATALINA_HOME%/webapps/jsp-examples/wroxjdbc directory. The file is calledJDBCTestPM.jsp. The code is listed here, with the hard-coded JDBC portion highlighted:<html><head><%@ page errorPage=‖errorpg.jsp‖import=‖java.sql.*,javax.sql.*,java.io.*‖ %></head><body><h1>JDBC JNDI Resource Test</h1><%!public void jspInit() {try {Class.forName(―com.codestudio.sql.PoolMan‖).newInstance();// Use the Connection to create Statements and do JDBC work} catch (Exception ex) {// JSP init() cannot throw any exceptionex.printStackTrace();}}%>By overriding jspInit(), the PoolMan driver class is loaded the first time JDBCTestPM.jsp is executed.The following highlighted code shows how to use the JDBC DriverManager class to get a JDBCconnection from PoolMan. This is the way JDBC connections were obtained with JDBC1, before the arrival of the JDBC 2 data source:<%Connection conn = DriverManager.getConnection(―jdbc:poolman://wroxtomcat‖); Statement stmt = conn.createStatement();ResultSet rset = stmt.executeQuery(―select * from employee;‖);%><table width=’600’ border=’1’><tr><th ali gn=’left’>Employee ID</th><th align=’left’>Name</th><th align=’left’>Department</th></tr><%while (rset.next()) {%><tr><td><%= rset.getString(1) %></td><td><%= rset.getString(2) %></td><td><%= rset.getString(4) %></td></tr><% }if (stmt != null)stmt.close();conn.close();%></table></body></html>The highlighted explicit call to conn.close() ensures that the connection is returned to the pool. Note that once the connection to the database is obtained, the code is almost identical to that of JDBCTest.jsp.However, the necessity to hard-code the driver class loading makes the code specific to the PoolMan connection manager. While this is backwardly compatible with JDBC 1, and supported by Tomcat 5, it is not a recommended practice.Testing PoolMan with a Legacy Hard-coded DriverTo test the JDBC 1 method of obtaining JDBC connections using PoolMan, start Tomcat 5 and try to access the JSP via the following URL:http://localhost:8080/jsp-examples/wroxjdbc/JDBCTestPM.jspThe screen that you see should display data from the employee table, similar to what is shown in Figure14-5. This is identical to the result from JDBCTest.jsp, where the default DBCP pooling was used.The first time the preceding URL is accessed, Tomcat 5 will compile the JSP and call jspInit(), loading the PoolMan class. The DriverManager URL lookup will then obtain the JDBC connection fromPoolMan. Your browser should display the employee table, similar to what is shown in Figure 14-5.Obtaining a Connection with JNDI MappingThe PoolMan 2.0 open-source project provides JNDI support when locating a JDBC data source.However, because of PoolMan’s vintage (the last update was in 2001), Tomcat 5–styled JNDI emulation is not directly supported.All that is needed for compatibility with Tomcat 5, however, is an object factory class to hand out the required data source. This class (calledcom.wrox.protc5.pmfact.PoolManFactory) is provided within the poolfact.jar file included with the code distribution (code/ch14 directory). You can use this class to replace Tomcat’s DBCP pool manager with PoolMan as an alternative. This will enable you to maintain JNDI-based access, keeping the application code highly portable. To use this class, copy it to the %CATALINA_HOME%/common/lib directory.To enable the access of PoolMan through Tomcat 5’s JNDI, it is necessary to edit the conf/server.xml file . Within the <DefaultContext> of the host named localhost, add the following resource and parameter declaration for the jdbc/wroxtomcat context:<Resour ce name=‖jdbc/wroxtomcat‖ auth=‖Container‖type=‖javax.sql.DataSource‖/><ResourceParams name=‖jdbc/wroxtomcat‖><parameter><name>factory</name><value>com.wrox.protc5.pmfact.PoolManFactory</value></parameter></ResourceParams>The factory parameter overrides the default factory of mons.dbcp. BasicDataSourceFactory. Instead, it is using our version (in com.wrox.protc5.pmfact. PoolManFactory), which will create PoolMan-managed data sources.To place a test JSP into the jsp-examples Web application, you must edit the deployment descriptor(web.xml) and add a reference <resource-ref> to the preceding resource:<resource-ref><res-ref-name>jdbc/wroxtomcat</res-ref-name><res-type>javax.sql.DataSource</res-type><res-auth>Container</res-auth></resource-ref>These configuration steps are identical to what was necessary when DBCP was used earlier in the setup of JDBCTest.jsp. In general, this would be the way to configure any alternative pooling mechanism that is compatible with Tomcat 5’s JNDI emul ation. Last but not least, a test JSP file must be created that makes use of the jdbc/wroxtomcat JNDI resource.To create this JSP file, it is only necessary to make a very small change to JDBCTest.jsp. The change required is highlighted in the following snippet, and the completed file is placed into the wroxjdbc subdirectory of the jsp-examples Web application. The newJSP is called JDBCTestPJ.jsp.<html><head><%@ page errorPage=‖errorpg.jsp‖import=‖java.sql.*,javax.sql.*,java.io.*,javax.naming.InitialContext,javax.naming.Context‖ %></head><body><h1>JDBC JNDI Resource Test</h1><%InitialContext initCtx = new InitialContext();DataSource ds = (DataSource)initCtx.lookup(―java:comp/env/jdbc/wroxtomcat‖);Connection conn = ds.getConnection();Statement stmt = conn.createStatement();ResultSet rset = stmt.executeQuery(―select * from employee;‖);Note that the code of JDBCTest.jsp and JDBCTestPJ.jsp is essentially identical. This demonstrates the advantage of decoupling the application code from the RDBMS accessed via JNDI. The same code can be used with connection pooling mechanisms from different vendors without change; only the configuration must be modified. The name of the JNDI resource is jdbc/wroxtomcat. Our customcom.wrox.protc5.pmfact.PoolManFactory code uses the part after jdbc/ to find the pool to be used. In this case, wroxtomcat matches a configured <dbname> element (see poolman.xml).Testing PoolMan with JNDI-Compatible LookupTo test PoolMan’s JNDI-compatible operation mode, shut down Tomcat 5 and restart it. This restart is not strictly necessary. However, restarting Tomcat will ensure that you begin with a clean slate, as the previous example loaded PoolMan. Next, try to access the JSP via the following URL:http://localhost:8080/jsp-examples/wroxjdbc/JDBCTestPJ.jspThe output from this example is again similar to what is shown in Figure 14-5.Note that the output is indistinguishable from that of JDBCTest.jsp or JDBCTestPM.jsp, although they each use distinctively different means to access and manage the JDBC connection used.As of this writing, the PoolMan 2.x project has been dormant on Source Forge for more than two years.In fact, some developers have started to fork the code base to add new functionality and fix bugs. While the coding and design is well ahead of its time with respect to application for Tomcat, it does bring upthe issue of ongoing support for anyone who may decide to adopt this pool manager. Deploying Third-Party PoolsHaving explored the issues surrounding the integration of third-party pool managers, carefully considerthe consequences of doing so before proceeding.Following are two main points that must be considered:❑Support—How well is the third-party pool manager supported? If there is any future incompatibilitywith Tomcat, who will resolve it and how soon?❑Code portability—Must one sacrifice configuration flexibility when using the pool manager? Is it necessary to hard-code driver and data source information?Because DBCP is an Apache Commons project, it is used by many Apache Jakarta projects. As such, it is likely to evolve and stabilize rapidly with contributions from the Jakarta community. Third-party connectionpool managers are unlikely to enjoy the same level of contribution and support.In addition, because it is an essential and integral part of Tomcat 5, DBCP technologywill track Tomcat evolution and will always be tested for compatibility with every new Tomcat release.Even if a production scenario forces the deployment of a non-standard pool manager, it is wise to considera gradual migration to standard DBCP. This is especially true if Tomcat 5 deployment is important.SummaryThis chapter explored JDBC connectivity in the context of Tomcat 5. The most obvious interaction is theneed for Web applications to connect to relational database sources.To conclude this chapter, let’s review some of th e key points that have been discussed: ❑ Java supports the accessing of RDBMSs in the form of JDBC. The evolution of JDBC versionswas examined, including coverage of each type of JDBC driver that is available.❑ With the latest Servlet 2.4 and JDBC 3.0 standards, the recommended way of providing a JDBCdata source to Web applications involves the configuration of JNDI resources in the Tomcatconfiguration file. In addition, Tomcat 5 provides a value-added database connection pooling service. This pooling service draws on the code from the Jakarta Commons DBCP project.❑ Using the latest MySQL and its Connector/J driver, JNDI resources can be configured for acustom JSP that accesses RDBMS tables to generate a dynamic HTML page.❑ Database connection pooling is required functionality for any serious Web application, but standard connection pooling on Tomcat is a relatively recent phenomenon. As a result, many current third-party solutions are notstandards-compliant. As administrators, it is important to realize the existence of such alternatives. In fact, many legacy systems today still deploy them, and some sharedhosting ISPs require the use of them.❑ A third-party pool manager called PoolMan can be deployed with Tomcat 5. This pool manager replaces the built-in DBCP-based connection pool. PoolMan can use a legacy JDBC 1 mechanism for providing pooled JDBC connection access to a Web application. As a result, the Web applicationcoding becomes specific to the pool manager, despite the fact that most of the application code can be reused. This raises serious questions about the actual value of such a third-party pool manager. However, it is possible to make this pool manager―Tomcat 5 JNDI-compatible‖ using a custom adapter/factory class. By using the custom factory, the Web application coding remains portable, and independent of the pool manager mechanism used. This example illustrates that the flexible JNDI-based data source distribution is not limited to Tomcat 5’s built-in DBCP based pool manager, but can be leveraged by any third-party pool manager as well.Chapter 15 examines Tomcat security.。
管理学原理英文版最新版教学课件第3章
Globe Findings
Global Leadership and Organizational Behavior Effectiveness (GLOBE)
Globe: Dimensions of Cultural Difference
Fundamentals of Management
Tenth Edition
Chapter 3 Integrative Managerial
Issues
Learning Objectives
3.1 Explain globalization and its impact on organizations.
Globalization and Its Impact
Global village: • a boundaryless world where goods and services are
produced and marketed worldwide.
What Does It Mean to Be "Global"?
How Do Organizations Go Global?obal
Source: Robbins, Stephen P., Coulter, Mary, Management, 13th Ed., © 2016, p. 106. Reprinted and electronically reproduced by permission of Pearson Education, Inc., New York, NY
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Chapter7Overview of Layer2 SwitchingIntroduction ................................................................................................... 7-2Switch Ports ................................................................................................... 7-2Enabling and Disabling Switch Ports ........................................................ 7-2Autonegotiation of Port Speed and Duplex Mode .................................... 7-3Port Trunking .......................................................................................... 7-3Link Access Control Protocol (LACP) ........................................................ 7-3Packet Storm Protection .......................................................................... 7-3Port Mirroring ......................................................................................... 7-3Port Security ............................................................................................ 7-4Virtual Local Area Networks (VLANs) .............................................................. 7-4Creating VLANs ....................................................................................... 7-5Summary of VLAN tagging rules .............................................................. 7-6VLAN Interaction with STPs and Trunk Groups ......................................... 7-6Generic VLAN Registration Protocol (GVRP) .................................................... 7-6Quality of Service ........................................................................................... 7-7Spanning Tree Protocol (STP) .......................................................................... 7-8Spanning Tree and Rapid Spanning Tree Port States ................................. 7-8Multiple Spanning Tree Protocol (MSTP) ................................................... 7-9IGMP Snooping ............................................................................................. 7-9Triggers .......................................................................................................... 7-97-2AlliedWare OS Software ReferenceSoftware Version 2.9.1C613-03126-00REV AIntroductionThis chapter outlines the Layer 2 and IP switching features on the switch, andhow to configure some of them. For more detail, see:■Chapter 8, Switching ■Chapter 40, Quality of Service (QoS) on Switch PortsSwitch PortsEach switch port is uniquely identified by a port number. The switch supportsa number of features at the physical level that allow it to be connected in avariety of physical networks. This physical layer (layer 1) versatility includes:■Enabling and disabling of ports.■Auto negotiation of port speed and duplex mode for all 10/100 BASE ports.■Manual setting of port speed and duplex mode for all 10/100 BASE ports.■Link up and link down triggers.■Port trunking.■Packet storm protection.■Port mirroring.■Support for SNMP management.Enabling and Disabling Switch PortsAn switch port that is enabled is available for packet reception andtransmission. Its administrative status in the Interfaces MIB is UP. Disabling aswitch port does not affect the STP operation on the port. Enabling a switchport will allow the port to participate in spanning tree negotiation. A switchport that has been disabled by the Port Security feature cannot be enabledusing the ENABLE SWITCH PORT command.To enable or disable a switch port, use the commands:ENABLE SWITCH PORT={port-list |ALL}DISABLE SWITCH PORT={port-list |ALL}Resetting ports at the hardware level discards all frames queued for receptionor transmission on the port, and restarts autonegotiation of port speed andduplex mode. Ports are reset using the command:RESET SWITCH PORT={port-list |ALL} [COUNTER]To display information about switch ports, use the command:SHOW SWITCH PORT[={port-list |ALL}]Overview of Layer2 Switching7-3Software Version2.9.1 C613-03126-00REV A Autonegotiation of Port Speed and Duplex ModeEach of the switch ports can operate at either 10 Mbps or 100 Mbps, in either full duplex or half duplex mode. In full duplex mode a port can transmit and receive data simultaneously, while in half duplex mode the port can either transmit or receive, but not at the same time. This versatility makes it possible to connect devices with different speeds and duplex modes to different ports on the switch. Such versatility also requires that each port on the switch know which speed and mode to use.Port TrunkingPort trunking, also known as port bundling or link aggregation, allows a number of ports to be configured to join together to make a single logical connection of higher bandwidth. This can be used where a higher performance link is required, and makes links even more reliable.Link Access Control Protocol (LACP)The Link Access Control Protocol (LACP) follows the IEEE Standard802.3-2002, CSMA/CD access method and physical layer specifications. It enables trunk groups, called aggregated links, to be created automatically. LACP operates where systems are connected over multiple communication links. It constantly monitors these links and automatically adds or removes them from trunk groups.Packet Storm ProtectionThe packet storm protection feature allows you to set limits on the reception rate of broadcast, multicast and destination lookup failure packets. The software allows separate limits to be set for each port, beyond which each of the different packet types are discarded. The software also allows separate limits to be set for each of the packet types. Which of these options can be implemented depends on the model of switch hardware.Port MirroringPort mirroring allows traffic being received and transmitted on a switch port to be sent to another switch port, the mirror port, usually for the purposes of capturing the data with a protocol analyser. This mirror port is the only switch port that belongs to no VLANs, and therefore does not participate in any other switching. Before the mirror port can be set, it must be removed from all VLANs except the default VLAN. The port cannot be part of a trunk group.7-4AlliedWare OS Software ReferenceSoftware Version 2.9.1C613-03126-00REV APort SecurityThe port security feature allows control over the stations connected to eachswitch port, by MAC address. If enabled on a port, the switch will learn MACaddresses up to a user-defined limit from 1 to 256, then lock out all other MACaddresses. One of the following options can be specified for the action takenwhen an unknown MAC address is detected on a locked port:■Discard the packet and take no further action,■Discard the packet and notify management with an SNMP trap,■Discard the packet, notify management with an SNMP trap and disable the port.Virtual Local Area Networks (VLANs)A Virtual LAN (VLAN) is a logical, software-defined subnetwork. It allowssimilar devices on the network to be grouped together into one broadcastdomain, irrespective of their physical position in the network. Multiple VLANscan be used to group workstations, servers, and other network equipmentconnected to the switch, according to similar data and security requirements.Decoupling logical broadcast domains from the physical wiring topologyoffers several advantages, including the ability to:■Move devices and people with minimal, or no, reconfiguration ■Change a device’s broadcast domain and access to resources withoutphysically moving the device, by software reconfiguration or by moving itscable from one switch port to another■Isolate parts of the network from other parts, by placing them in differentVLANs■Share servers and other network resources without losing data isolation orsecurity■Direct broadcast traffic to only those devices which need to receive it, toreduce traffic across the network■Connect 802.1Q-compatible switches together through one port on eachswitch Devices that are members of the same VLAN only exchange data with eachother through the switch’s switching capabilities. To exchange data betweendevices in separate VLANs, the switch’s routing capabilities are used. Theswitch passes VLAN status information, indicating whether a VLAN is up ordown, to the Internet Protocol (IP) module. IP uses this information todetermine route availability.The switch has a maximum of 255 VLANs, ranging from a VLAN identifier(VID) of 1 to 4094. When the switch is first powered up, a “default” VLAN iscreated and all ports are added to it. In this initial unconfigured state, theswitch will broadcast all the packets it receives to the default VLAN. ThisVLAN has a VID of 1 and an interface name of vlan1. It cannot be deleted, andports can only be removed from it if they also belong to at least one otherOverview of Layer2 Switching7-5Software Version2.9.1 C613-03126-00REV A VLAN. The default VLAN cannot be added to any STP, but always belongs to the default STP. If all the devices on the physical LAN are to belong to the same logical LAN, that is, the same broadcast domain, then the default settings will be acceptable, and no additional VLAN configuration is required. Creating VLANsTo briefly summarise the process of creating a VLAN:1.Create the VLAN.2.Add tagged ports to the VLAN, if required.3.Add untagged ports to the VLAN, if required.To create a VLAN, use the command:CREATE VLAN=vlan-name VID=2..4094Every port must belong to a VLAN, unless it is the mirror port. By default, all ports belong to the default VLAN as untagged ports.To add tagged ports to a VLAN, use the command:ADD VLAN={vlan-name|1..4094} PORT={port-list|ALL}FRAME=TAGGEDA port can be tagged for any number of VLANs.To add untagged ports to a VLAN, use the command:ADD VLAN={vlan-name|1..4094} PORT={port-list|ALL}[FRAME=UNTAGGED]A port can be untagged for zero or one VLAN. A port can only be added to the default VLAN as an untagged port if it is not untagged for another VLAN. A port cannot transmit both tagged and untagged frames for the same VLAN (that is, it cannot be added to a VLAN as both a tagged and an untagged port). To remove ports from a VLAN, use the command:DELETE VLAN={vlan-name|1..4094} PORT={port-list|ALL} Removing an untagged port from a VLAN will return it to the default VLAN, unless it is a tagged port for another static VLAN. An untagged port can only be deleted from the default VLAN if the port is a tagged port for another static VLAN.Ports tagged for some VLANs and left in the default VLAN as untagged ports will transmit broadcast traffic for the default VLAN. If this is not required, the unnecessary traffic in the switch can be reduced by deleting those ports from the default VLAN.To change the tagging status of a port in a VLAN, use the command: SET VLAN={vlan-name|1..4094} PORT={port-list|ALL}FRAME=TAGGEDTo destroy a VLAN, use the command:DESTROY VLAN={vlan-name|2..4094|ALL}7-6AlliedWare OS Software ReferenceVLANs can only be destroyed if no ports belong to them.To display the VLANs configured on the switch, use the command:SHOW VLAN[={vlan-name|1..4094|ALL}]To view packet reception and transmission counters for a VLAN, use thecommand (see Chapter11, Interfaces):SHOW INTERFACE=VLAN n COUNTERSummary of VLAN tagging rulesWhen designing a VLAN and adding ports to VLANs, the following rulesapply.1.Each port, except for the mirror port, must belong to at least one staticVLAN. By default, a port is an untagged member of the default VLAN.2. A port can be untagged for zero or one VLAN. A port that is untagged fora VLAN transmits frames destined for that VLAN without a VLAN tag inthe Ethernet frame.3. A port can be tagged for zero or more VLANs. A port that is tagged for aVLAN transmits frames destined for that VLAN with a VLAN tag,including the numerical VLAN Identifier of the VLAN.4. A port cannot be untagged and tagged for the same VLAN.5.The mirror port, if there is one, is not a member of any VLAN.VLAN Interaction with STPs and Trunk GroupsVLANs may have ports in more than one STP, when the ports belong tomultiple VLANs. VLANs can belong to multiple STPs.All the ports in a trunk group must have the same VLAN configuration: theymust belong to the same VLANs and have the same tagging status, and canonly be operated on as a group.Generic VLAN Registration Protocol(GVRP)The GARP application GVRP allows switches in a network to dynamicallyshare VLAN membership information, to reduce the need for staticallyconfiguring all VLAN membership changes on all switches in a network. Fordetailed information see Chapter10, Generic Attribute Registration Protocol(GARP).Software Version2.9.1C613-03126-00REV AOverview of Layer2 Switching7-7Software Version2.9.1 C613-03126-00REV A Quality of ServiceQuality of Service (QoS) enables you to prioritise traffic and/or limit the bandwidth available to it. The concept of QoS is a departure from the original networking protocols, which treated all traffic on the Internet or within a LAN the same. Without QoS, every different traffic type is equally likely to be dropped if a link becomes oversubscribed. This approach is now inadequate in many networks, because traffic levels have increased and networks transport time-critical applications such as streams of video data. QoS also enables service providers to easily supply different customers with different amounts of bandwidth.Configuring Quality of Service involves two separate stages:1.Classifying traffic into flows, according to a wide range of criteria.Classification is performed by the switch’s packet classifier. It is described in Chapter39, Generic Packet Classifier.2.Acting on these traffic flows.Approaches, methods and commands for this are described Chapter40, Quality of Service (QoS) on Switch Ports.Rapier i Series switches include full QoS functionality, including■policies, to provide a QoS configuration for a port or ports■traffic classes, for bandwidth limiting and user prioritisation■maximum bandwidth limiting on a traffic class■flow groups within traffic classes, for user prioritisation■control of the egress scheduling algorithm■priority relabelling of frames, at Layer 2, by replacing the VLAN tag User Priority field■class of service relabelling of frames, at Layer 3, by replacing the DSCP (DiffServ Code Point) or the TOS precedence value in the IP header’s Type of Service (TOS) fieldT able 7-1: The different QoS-type controls available on the switchCommand set Use for Do not use forQoS Bandwidth limiting of classified traffic flows.Priority queuing of classified traffic flows.Replacing TOS or DSCP byte of IP header.Replacing User Priority in VLAN tag header.Providing a coordinated QoS solution for a port orports, using the QoS policy model.Configuring a DiffServ domain.Limiting total bandwidth on a port, unless other QoS controls are also required.7-8AlliedWare OS Software Reference Software Version 2.9.1C613-03126-00REV ASpanning Tree Protocol (STP)The Spanning Tree Protocol (STP) makes it possible to automatically disableredundant paths in a network to avoid loops, and enable them when a fault inthe network means they are needed to keep traffic flowing. A sequence ofLANs and switches may be connected together in an arbitrary physicaltopology resulting in more than one path between any two switches. If a loopexists, frames transmitted onto the extended LAN would circulate around theloop indefinitely, decreasing the performance of the extended LAN. On theother hand, multiple paths through the extended LAN provide the opportunityfor redundancy and backup in the event of a bridge experiencing a fatal errorcondition.The spanning tree algorithm ensures that the extended LAN contains no loopsand that all LANs are connected by:■Detecting the presence of loops and automatically computing a logicalloop-free portion of the topology, called a spanning tree . The topology isdynamically pruned to a spanning tree by declaring the ports on a switchredundant, and placing the ports into a ‘Blocking’ state.■Automatically recovering from a switch failure that would partition theextended LAN by reconfiguring the spanning tree to use redundant paths,if available.Spanning Tree and Rapid Spanning Tree PortStatesIf STP is running in STANDARD mode, then each port can be in one of fiveSpanning Tree states, and one of two switch states. If STP is running in RAPIDmode, then each port can be in one of four states. The state of a switch port isHardware packet filters Priority queuing of classified traffic flows.Replacing TOS or DSCP byte of IP header.Replacing User Priority in VLAN tag header.Forwarding a flow that is marked to be dropped (forexample, because bandwidth allocation is exceeded).Specifying actions for packets which match the ingressand egress ports of a classifier (if set), but do not matchthe classifier’s other parameters.Configuring a simple DiffServ domain.Bandwidth limiting.Configuring most DiffServ yer 3 switch filters Priority queuing of up to 16 distinctly different types of traffic flow.Replacing TOS or DSCP byte of IP header.Replacing User Priority in VLAN tag header.QoS for non-IP traffic (e.g. IPX).QoS based on VLANs.Bandwidth limiting.SET SWITCH PORT Limiting total ingress and/or egress bandwidth onports.Limiting bandwidth of particular types of traffic.Limiting egress bandwidth if priorityqueuing is also required.T able 7-1: The different QoS-type controls available on the switch (cont.)Command set Use for Do not use forOverview of Layer2 Switching7-9Software Version2.9.1 C613-03126-00REV A taken into account by STP. To be involved in STP negotiations, STP must be enabled on the switch, the port must be enabled on the switch, and enabled for the STP it belongs to.Multiple Spanning Tree Protocol (MSTP)Multiple Spanning Tree Protocol (MSTP) was developed to address limitations in the existing protocols, Spanning Tree Protocol (STP) and Rapid Spanning Tree Protocol (RSTP). These limitations apply mainly to networks that use multiple VLANS with topologies employing alternative physical links. MSTP is defined in IEEE Standard802.1Q 2003.For detailed information, see “Multiple Spanning Tree Protocol (MSTP)” on page9-13 of Chapter9, Spanning Trees.IGMP SnoopingIGMP (Internet Group Management Protocol) is used by IP hosts to report their multicast group memberships to routers and switches. IP hosts join a multicast group to receive broadcast messages directed to the multicast group address. IGMP is an IP-based protocol and uses IP addresses to identify both the multicast groups and the host members. For a VLAN-aware devices, this means multicast group membership is on a per-VLAN basis. If at least one port in the VLAN is a member of a multicast group, by default multicast packets will be flooded onto all ports in the VLAN.IGMP snooping enables the switch to forward multicast traffic intelligently on the switch. The switch listens to IGMP membership reports, queries and leave messages to identify the switch ports that are members of multicast groups. Multicast traffic will only be forwarded to ports identified as members of the specific multicast group.IGMP snooping is performed at Layer 2 on VLAN interfaces automatically. By default, the switch will only forward traffic out those ports with multicast listeners, therefore it will not act as a simple hub and flood all multicast traffic out all ports. IGMP snooping is independent of the IGMP and Layer 3 configuration, so an IP interface does not have to be attached to the VLAN, and IGMP does not have to be enabled or configured.IGMP snooping is enabled by default. To disable it, use the command: DISABLE IGMPSNOOPINGFor more information, see Chapter27, IP Multicasting.TriggersThe Trigger Facility can be used to automatically run specified command scripts when particular triggers are activated. When a trigger is activated by an event, global parameters and parameters specific to the event are passed to the script that is run. For more information, see Chapter60, Trigger Facility.7-10AlliedWare OS Software ReferenceThe switch can generate triggers to activate scripts when a fibre uplink portloses or gains coherent light. To create or modify a switch trigger, use thecommands:CREATE TRIGGER=trigger-id MODULE=SWITCHEVENT={LIGHTOFF|LIGHTON} PORT=port [AFTER=hh:mm][BEFORE=hh:mm] [DATE=date|DAYS=day-list] [NAME=name][REPEAT={YES|NO|ONCE|FOREVER|count}] [SCRIPT=filename...][STATE={ENABLED|DISABLED}] [TEST={YES|NO|ON|OFF}]SET TRIGGER=trigger-id PORTS={port-list|ALL} [AFTER=hh:mm][BEFORE=hh:mm] [DATE=date|DAYS=day-list] [NAME=name][REPEAT={YES|NO|ONCE|FOREVER|count}][TEST={YES|NO|ON|OFF}]The following sections list the events that may be specified for the EVENTparameter, the parameters that may be specified as module-specific-parameters,and the arguments passed to the script activated by the trigger.Event LINKDOWNDescription The port link specified by the PORT parameter has just gone down.Parameters The following command parameter(s) must be specified in the CREATE/SETTRIGGER commands:Parameter DescriptionPORT=port The port on which the event will activate the trigger.Script Parameters The trigger passes the following parameter(s) to the script:Argument Description%1The port number of the port which has just gone down.Event LINKUPDescription The port link specified by the PORT parameter has just come up.Parameters The following command parameter(s) must be specified in the CREATE/SETTRIGGER commands:Parameter DescriptionPORT=port The port on which the event will activate the trigger.Script Parameters The trigger passes the following parameter(s) to the script:Argument Description%1The port number of the port which has just come up.Software Version2.9.1C613-03126-00REV A。
Ovation I O Reference Manual
This publication adds the Eight Channel RTD module to the Ovation I/O Reference Manual. It should be placed between Sections 19 and 20.Date: 04/03IPU No.243Ovation ® Interim Publication UpdatePUBLICATION TITLEOvation I/O Reference ManualPublication No. R3-1150Revision 3, March 2003Section 19A. Eight Channel RTDModule19A-1. DescriptionThe Eight (8) channel RTD module is used to convert inputs from Resistance Temperature Detectors (RTDs) to digital data. The digitized data is transmitted to the Controller.19A-2. Module Groups19A-2.1. Electronics ModulesThere is one Electronics module group for the 8 channel RTD Module:n5X00119G01 converts inputs for all ranges and is compatible only with Personality module 5X00121G01 (not applicable for CE Mark certified systems).19A-2.2. Personality ModulesThere is one Personality module groups for the 8 channel RTD Module:n5X00121G01 converts inputs for all ranges and is compatible only with Electronics module 5x00119G01 (not applicable for CE Mark certified systems).19A-2.3. Module Block Diagram and Field Connection WiringDiagramThe Ovation 8 Channel RTD module consists of two modules an electronics module contains a logic printed circuit board (LIA) and a printed circuit board (FTD). The electronics module is used in conjunction with a personalty module, which contains a single printed circuit board (PTD). The block diagram for the 8 channel RTD moduleis shown in Figure 19A-1.Table 19A-1. 8 Channel RTD Module Subsystem ChannelsElectronic Module Personality Module85X00119G015X00121G01Figure 19A-1. 8 Channel RTD Module Block Diagram and Field Connection Wiring Diagram19A-3. SpecificationsElectronics Module (5X00119)Personality Module (5X00121)Table 19A-2. 8 Channel RTD Module SpecificationsDescription ValueNumber of channels8Sampling rate50 HZ mode: 16.67/sec. normally. In 3 wire mode, leadresistance measurement occurs once every 6.45 sec.during which the rate drops to 3/sec.60 HZ mode: 20/sec. normally. In 3 wire mode, leadresistance measurement occurs once every 6.45 sec.during which the rate drops to 2/sec.Self Calibration Mode: Occurs on demand only. The ratedrops to 1/sec. once during each self calibration cycle.RTD ranges Refer to Table 19A-3.Resolution12 bitsGuaranteed accuracy (@25°C)0.10% ±[0.045 (Rcold/Rspan)]% ± [((Rcold + Rspan)/4096 OHM)]% ± [0.5 OHM/Rspan]% ±10 m V ± 1/2LSBwhere:Rcold and Rspan are in Ohms.Temperature coefficient 10ppm/°CDielectric isolation:Channel to channel Channel to logic 200V AC/DC 1000 V AC/DCInput impedance100 M OHM50 K OHM in power downModule power 3.6 W typical; 4.2 W maximumOperating temperature range0 to 60°C (32°F to 140°F)Storage temperature range-40°C to 85°C (-40°F to 185°F)Humidity (non-condensing)0 to 95%Self Calibration On Demand by Ovation ControllerCommon Mode Rejection120 dB @ DC and nominal power line frequency+/- 1/2%Normal Mode Rejection100 dB @ DC and nominal power line frequency+/- 1/2%Table 19A-3. 8 Channel RTD RangesScale #(HEX)Wires Type Tempo FTempo CRcold(ohm)Rhot(ohm)Excitationcurrent(ma)Accuracy± ±countsAccuracy± ±% ofSPAN1310OhmPL0 to1200–18 t o6496106.3 1.090.222310OhmCU 0 to302–18 t o1508.516.5 1.0 130.32D350OhmCU 32 to2840 to1405080 1.0110.2711350OhmCU 32 to2300 to1105378 1.0120.30193100Ohm PL –4 to334–16 t o16892163.671.0110.27223100Ohm PL 32 to5200 to269100200 1.0100.25233100Ohm PL 32 to10400 to561100301 1.0100.25253120Ohm NI –12 t o464–11 t o240109360 1.0100.25263120Ohm NI 32 to1500 to70120170 1.0130.32283120Ohm NI 32 to2780 to122120225 1.0110.27804100Ohm PL 32 to5440 to290100 208 1.0100.25814100Ohm PL 356 t o446180 t o230168 186 1.0300.74824200Ohm PL 32 to6980 to370200 473 1.0120.30834200Ohm PL 514 t o648268 t o342402452 1.0290.71844100Ohm PL 32 to1240 to51100120 1.0190.47854100Ohm PL 32 to2170 to103100 140 1.0130.3286 4100Ohm PL 32 to4120 to211100 180 1.0110.27874100Ohm PL 32 to7140 to379100 240 1.0100.25884120Ohm PL 511 t o662266 t o350200230 1.0240.5919A-4. 8 Channel RTD Terminal Block Wiring Information19A-4.1. Systems Using Personality Module 5X00121G01 Each Personality module has a simplified wiring diagram label on its side, which appears above the terminal block. This diagram indicates how the wiring from the field is to beconnected to the terminal block in the base unit. The following table lists and defines the abbreviations used in this diagram.Table 19A-4. Abbreviations Used in the DiagramAbbreviation Definition+IN, -IN Positive and negative sense input connectionEarth ground terminal. Used for landing shields when the shield is to begrounded at the module.PS+, PS-Auxiliary power supply terminals.RTN Return for current source connection.SH Shield connector. used for landing shields when the shield is to begrounded at the RTD.SRC Current source connection.Note:PS+ and PS- are not used by this module.19A-5. 8 Channel RTD Module Address Locations19A-5.1. Configuration and Status RegisterWord address 13 (D in Hex) is used for both module configuration and module status. The Module Status Register has both status and diagnostic information. The bit information contained within these words is shown in Table 19A-5.Definitions for the Configuration/Module Status Register bits:Bit 0:This bit configures the module (write) or indicates the configuration state of the module (read). A “1” indicates that the module is configured. Note that until the module is configured, reading from addresses #0 through #11 (B in Hex) will produce an attention status.Bit 1:This bit (write “1”) forces the module into the error state, resulting in the error LED being lit. The read of bit “1” indicates that there is an internal module error,or the controller has forced the module into the error state. The state of this bit is always reflected by the module’s Internal Error LED. Whenever this bit is set,an attention status is returned to the controller when address #0 through #11(B in Hex) are read.Table 19A-5. 8 Channel RTD Configuration/Status Register (Address 13 0xD in Hex)Bit Data Description -Configuration Register (Write)Data Description -Status Register (Read)0Configure Module Module Configured(1 = configured; 0 = unconfigured)1Force errorInternal or forced error(1 = forced error; 0 = no forced error)250/60 Hz select (0 = 60Hz, 1 = 50Hz)50/60 Hz System (1 = 50Hz) d(read back)3SELF_CAL (Initiates Self Calibration)Warming bit (set during power up or configuration)40050060Module Not Calibrated 708CH.1 _ 3/4 Wire.CH.1 _ 3/4 Wire - Configuration (read back)9CH.2 _ 3/4 Wire.CH.2 _ 3/4 Wire - Configuration (read back)10CH.3 _ 3/4 Wire.CH.3 _ 3/4 Wire - Configuration (read back)11CH.4 _ 3/4 Wire.CH.4 _ 3/4 Wire - Configuration (read back)12CH.5 _ 3/4 Wire.CH.5 _ 3/4 Wire - Configuration (read back)13CH.6 _ 3/4 Wire.CH.6 _ 3/4 Wire - Configuration (read back)14CH.7 _ 3/4 Wire.CH.7 _ 3/4 Wire - Configuration (read back)15CH.8 _ 3/4 Wire.CH.8 _ 3/4 Wire - Configuration (read back)Bit 2:The status of this bit (read) indicates the conversion rate of the module, write to this bit configures the conversion rate of A/D converters as shown below.see Table 19A-6.Bit3:Write: This bit is used to initiate self-calibration. Read: This bit indicates that the module is in the “Warming” state. this state exists after power up and ter-minates after 8.16 seconds. the module will be in the error condition during the warm up period.Bit4 & 5:These bits are not used and read as “0” under normal operation.Bit 6:This bit (read) is the result of a checksum test of the EEPROM. A failure of this test can indicate a bad EEPROM, but it typically indicates that the module has not been calibrated. A “0” indicates that there is no error condition. If an error is present, the internal error LED is lit and attention status will be returned for all address offsets 0-11 (0x0 - 0xB). The “1” state of this bit indicates an unre-coverable error condition in the field.Bit 7:This bits is not used and read as “0” under normal operation.Bit 8 - 15:These bits are used to configure channels 1 - 8 respectively for 3 or 4 wire op-eration. A “0” indicates 3 wire and a “1” indicates 4 wire operation, see Table 19A-7 and Table 19A-8).Word address 12 (0xC) is used to configure the appropriate scales for Channels 1 - 4 (refer to Table 19A-7 and Table 19A-8).Table 19A-6. Conversion Rate Conversion Rate (1/sec.)Bit 260 (for 60Hz systems)050 (for 50Hz systems)1Table 19A-7. Data Format for the Channel Scale Configuration Register(0xC)Bit Data Description Configuration (Write)Data Description Status (Read)0 Configure Channel #1scale - Bit 0Channel #1 scale configuration (read back) - Bit 01Configure Channel #1scale - Bit 1Channel #1 scale configuration (read back) - Bit 12Configure Channel #1scale - Bit 2Channel #1 scale configuration (read back) - Bit 23Configure Channel #1scale - Bit 3Channel #1 scale configuration (read back) - Bit 34Configure Channel #2 scale - Bit 0Channel #2 scale configuration (read back) - Bit 05Configure Channel #2 scale - Bit 1Channel #2 scale configuration (read back) - Bit 16Configure Channel #2 scale - Bit 2Channel #2 scale configuration (read back) - Bit 27Configure Channel #2 scale - Bit 3Channel #2 scale configuration (read back) - Bit 38Configure Channel #3 scale - Bit 0Channel #3 scale configuration (read back) - Bit 09Configure Channel #3 scale - Bit 1Channel #3 scale configuration (read back) - Bit 1Caution:Configuring any or all channel scales while the system is running will cause all channels to return attention status for up to two seconds following the reconfiguration.Caution:Configuring any or all channel scales while the system is running will cause all channels to return attention status for up to two seconds following the reconfiguration.10Configure Channel #3 scale - Bit 2Channel #3 scale configuration (read back) - Bit 211Configure Channel #3 scale - Bit 3Channel #3 scale configuration (read back) - Bit 312Configure Channel #4 scale - Bit 0Channel #4 scale configuration (read back) - Bit 013Configure Channel #4 scale - Bit 1Channel #4 scale configuration (read back) - Bit 114Configure Channel #4 scale - Bit 2Channel #4 scale configuration (read back) - Bit 215Configure Channel #4 scale - Bit 3Channel #4 scale configuration (read back) - Bit 3Table 19A-8. Data Format for the Channel Scale Configuration Register(0xE)Bit Data Description Configuration (Write)Data Description Status (Read)0 Configure Channel #5 scale - Bit 0Channel #5 scale configuration (read back) - Bit 01Configure Channel #5 scale - Bit 1Channel #5 scale configuration (read back) - Bit 12Configure Channel #5 scale - Bit 2Channel #5 scale configuration (read back) - Bit 23Configure Channel #5 scale - Bit 3Channel #5 scale configuration (read back) - Bit 34Configure Channel #6 scale - Bit 0Channel #6 scale configuration (read back) - Bit 05Configure Channel #6 scale - Bit 1Channel #6 scale configuration (read back) - Bit 16Configure Channel #6 scale - Bit 2Channel #6 scale configuration (read back) - Bit 27Configure Channel #6 scale - Bit 3Channel #6 scale configuration (read back) - Bit 38Configure Channel #7 scale - Bit 0Channel #7 scale configuration (read back) - Bit 09Configure Channel #7 scale - Bit 1Channel #7 scale configuration (read back) - Bit 110Configure Channel #7 scale - Bit 2Channel #7 scale configuration (read back) - Bit 211Configure Channel #7 scale - Bit 3Channel #7 scale configuration (read back) - Bit 312Configure Channel #8 scale - Bit 0Channel #8 scale configuration (read back) - Bit 013Configure Channel #8 scale - Bit 1Channel #8 scale configuration (read back) - Bit 114Configure Channel #8 scale - Bit 2Channel #8 scale configuration (read back) - Bit 215Configure Channel #8 scale - Bit 3Channel #8 scale configuration (read back) - Bit 3Table 19A-7. Data Format for the Channel Scale Configuration Register(0xC)19A-6. Diagnostic LEDsTable 19A-9. 8 Channel RTD Diagnostic LEDsLED DescriptionP (Green)Power OK LED. Lit when the +5V power is OK.C (Green)Communications OK LED. Lit when the Controller is communicatingwith the module.I (Red)Internal Fault LED. Lit whenever there is any type of error with themodule except to a loss of power. Possible causes are:n - Module initialization is in progress.n - I/O Bus time-out has occurred.n - Register, static RAM, or FLASH checksum error.n - Module resetn - Module is uncalibrated.n - Forced error has been received from the Controllern - Communication between the Field and Logic boards failedCH1 - CH 8 (Red)Channel error. Lit whenever there is an error associated with a channel or channels. Possible causes are:n - Positive overrangen - Negative overrangen Communication with the channel has failed。
3. 第三章课后习题及答案
第三章1. (Q1) Suppose the network layer provides the following service. The network layer in the source host accepts a segment of maximum size 1,200 bytes and a destination host address from the transport layer. The network layer then guarantees to deliver the segment to the transport layer at the destination host. Suppose many network application processes can be running at the destination host.a. Design the simplest possible transport-layer protocol that will get application data to thedesired process at the destination host. Assume the operating system in the destination host has assigned a 4-byte port number to each running application process.b. Modify this protocol so that it provides a “return address” to the destination process.c. In your protocols, does the transport layer “have to do anything” in the core of the computernetwork.Answer:a. Call this protocol Simple Transport Protocol (STP). At the sender side, STP accepts from thesending process a chunk of data not exceeding 1196 bytes, a destination host address, and a destination port number. STP adds a four-byte header to each chunk and puts the port number of the destination process in this header. STP then gives the destination host address and the resulting segment to the network layer. The network layer delivers the segment to STP at the destination host. STP then examines the port number in the segment, extracts the data from the segment, and passes the data to the process identified by the port number.b. The segment now has two header fields: a source port field and destination port field. At thesender side, STP accepts a chunk of data not exceeding 1192 bytes, a destination host address,a source port number, and a destination port number. STP creates a segment which contains theapplication data, source port number, and destination port number. It then gives the segment and the destination host address to the network layer. After receiving the segment, STP at the receiving host gives the application process the application data and the source port number.c. No, the transport layer does not have to do anything in the core; the transport layer “lives” inthe end systems.2. (Q2) Consider a planet where everyone belongs to a family of six, every family lives in its own house, each house has a unique address, and each person in a given house has a unique name. Suppose this planet has a mail service that delivers letters form source house to destination house. The mail service requires that (i) the letter be in an envelope and that (ii) the address of the destination house (and nothing more ) be clearly written on the envelope. Suppose each family has a delegate family member who collects and distributes letters for the other family members. The letters do not necessarily provide any indication of the recipients of the letters.a. Using the solution to Problem Q1 above as inspiration, describe a protocol that thedelegates can use to deliver letters from a sending family member to a receiving family member.b. In your protocol, does the mail service ever have to open the envelope and examine theletter in order to provide its service.Answer:a.For sending a letter, the family member is required to give the delegate the letter itself, theaddress of the destination house, and the name of the recipient. The delegate clearly writes the recipient’s name on the top of the letter. The delegate then puts the letter in an e nvelope and writes the address of the destination house on the envelope. The delegate then gives the letter to the planet’s mail service. At the receiving side, the delegate receives the letter from the mail service, takes the letter out of the envelope, and takes note of the recipient name written at the top of the letter. The delegate than gives the letter to the family member with this name.b.No, the mail service does not have to open the envelope; it only examines the address on theenvelope.3. (Q3) Describe why an application developer might choose to run an application over UDP rather than TCP.Answer:An application developer may not want its application to use TCP’s congestion control, which can throttle the application’s sending rate at times of congestion. Often, designers of IP telephony and IP videoconference applications choose to run their applications over UDP because they want to avoid TCP’s congestion control. Also, some applications do not need the reliable data transfer provided by TCP.4. (P1) Suppose Client A initiates a Telnet session with Server S. At about the same time, Client B also initiates a Telnet session with Server S. Provide possible source and destination port numbers fora. The segment sent from A to B.b. The segment sent from B to S.c. The segment sent from S to A.d. The segment sent from S to B.e. If A and B are different hosts, is it possible that the source port number in the segment fromA to S is the same as that fromB to S?f. How about if they are the same host?Yes.f No.5. (P2) Consider Figure 3.5 What are the source and destination port values in the segmentsflowing form the server back to the clients’ processes? What are the IP addresses in the network-layer datagrams carrying the transport-layer segments?Answer:Suppose the IP addresses of the hosts A, B, and C are a, b, c, respectively. (Note that a,b,c aredistinct.)To host A: Source port =80, source IP address = b, dest port = 26145, dest IP address = a To host C, left process: Source port =80, source IP address = b, dest port = 7532, dest IP address = cTo host C, right process: Source port =80, source IP address = b, dest port = 26145, dest IP address = c6. (P3) UDP and TCP use 1s complement for their checksums. Suppose you have the followingthree 8-bit bytes: 01101010, 01001111, 01110011. What is the 1s complement of the sum of these 8-bit bytes? (Note that although UDP and TCP use 16-bit words in computing the checksum, for this problem you are being asked to consider 8-bit sums.) Show all work. Why is it that UDP takes the 1s complement of the sum; that is , why not just sue the sum? With the 1s complement scheme, how does the receiver detect errors? Is it possible that a 1-bit error will go undetected? How about a 2-bit error?Answer:One's complement = 1 1 1 0 1 1 1 0.To detect errors, the receiver adds the four words (the three original words and the checksum). If the sum contains a zero, the receiver knows there has been an error. All one-bit errors will be detected, but two-bit errors can be undetected (e.g., if the last digit of the first word is converted to a 0 and the last digit of the second word is converted to a 1).7. (P4) Suppose that the UDP receiver computes the Internet checksum for the received UDPsegment and finds that it matches the value carried in the checksum field. Can the receiver be absolutely certain that no bit errors have occurred? Explain.Answer:No, the receiver cannot be absolutely certain that no bit errors have occurred. This is because of the manner in which the checksum for the packet is calculated. If the corresponding bits (that would be added together) of two 16-bit words in the packet were 0 and 1 then even if these get flipped to 1 and 0 respectively, the sum still remains the same. Hence, the 1s complement the receiver calculates will also be the same. This means the checksum will verify even if there was transmission error.8. (P5) a. Suppose you have the following 2 bytes: 01001010 and 01111001. What is the 1scomplement of sum of these 2 bytes?b. Suppose you have the following 2 bytes: 11110101 and 01101110. What is the 1s complement of sum of these 2 bytes?c. For the bytes in part (a), give an example where one bit is flipped in each of the 2 bytesand yet the 1s complement doesn’t change.0 1 0 1 0 1 0 1 + 0 1 1 1 0 0 0 0 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 + 0 1 0 0 1 1 0 0 0 0 0 1 0 0 0 1Answer:a. Adding the two bytes gives 10011101. Taking the one’s complement gives 01100010b. Adding the two bytes gives 00011110; the one’s complement gives 11100001.c. first byte = 00110101 ; second byte = 01101000.9. (P6) Consider our motivation for correcting protocol rdt2.1. Show that the receiver, shown inthe figure on the following page, when operating with the sender show in Figure 3.11, can lead the sender and receiver to enter into a deadlock state, where each is waiting for an event that will never occur.Answer:Suppose the sender is in state “Wait for call 1 from above” and the receiver (the receiver shown in the homework problem) is in state “Wait for 1 from below.” The sender sends a packet with sequence number 1, and transitions to “Wait for ACK or NAK 1,” waiting for an ACK or NAK. Suppose now the receiver receives the packet with sequence number 1 correctly, sends an ACK, and transitions to state “Wait for 0 from below,” waiting for a data packet with sequence number 0. However, the ACK is corrupted. When the rdt2.1 sender gets the corrupted ACK, it resends the packet with sequence number 1. However, the receiver is waiting for a packet with sequence number 0 and (as shown in the home work problem) always sends a NAK when it doesn't get a packet with sequence number 0. Hence the sender will always be sending a packet with sequence number 1, and the receiver will always be NAKing that packet. Neither will progress forward from that state.10. (P7) Draw the FSM for the receiver side of protocol rdt3.0Answer:The sender side of protocol rdt3.0 differs from the sender side of protocol 2.2 in that timeouts have been added. We have seen that the introduction of timeouts adds the possibility of duplicate packets into the sender-to-receiver data stream. However, the receiver in protocol rdt.2.2 can already handle duplicate packets. (Receiver-side duplicates in rdt 2.2 would arise if the receiver sent an ACK that was lost, and the sender then retransmitted the old data). Hence the receiver in protocol rdt2.2 will also work as the receiver in protocol rdt 3.0.11. (P8) In protocol rdt3.0, the ACK packets flowing from the receiver to the sender do not havesequence numbers (although they do have an ACK field that contains the sequence number of the packet they are acknowledging). Why is it that our ACK packets do not require sequence numbers?Answer:To best Answer this question, consider why we needed sequence numbers in the first place. We saw that the sender needs sequence numbers so that the receiver can tell if a data packet is a duplicate of an already received data packet. In the case of ACKs, the sender does not need this info (i.e., a sequence number on an ACK) to tell detect a duplicate ACK. A duplicate ACK is obvious to the rdt3.0 receiver, since when it has received the original ACK it transitioned to the next state. The duplicate ACK is not the ACK that the sender needs and hence is ignored by the rdt3.0 sender.12. (P9) Give a trace of the operation of protocol rdt3.0 when data packets and acknowledgmentpackets are garbled. Your trace should be similar to that used in Figure 3.16Answer:Suppose the protocol has been in operation for some time. The sender is in state “Wait for call fro m above” (top left hand corner) and the receiver is in state “Wait for 0 from below”. The scenarios for corrupted data and corrupted ACK are shown in Figure 1.13. (P10) Consider a channel that can lose packets but has a maximum delay that is known.Modify protocol rdt2.1 to include sender timeout and retransmit. Informally argue whyyour protocol can communicate correctly over this channel.Answer:Here, we add a timer, whose value is greater than the known round-trip propagation delay. We add a timeout event to the “Wait for ACK or NAK0” and “Wait for ACK or NAK1” states. If the timeout event occurs, the most recently transmitted packet is retransmitted. Let us see why this protocol will still work with the rdt2.1 receiver.• Suppose the timeout is caused by a lost data packet, i.e., a packet on the senderto- receiver channel. In this case, the receiver never received the previous transmission and, from the receiver's viewpoint, if the timeout retransmission is received, it look exactly the same as if the original transmission is being received.• Suppose now that an ACK is lost. The receiver will eventually retransmit the packet on atimeout. But a retransmission is exactly the same action that is take if an ACK is garbled. Thus the sender's reaction is the same with a loss, as with a garbled ACK. The rdt 2.1 receiver can already handle the case of a garbled ACK.14. (P11) Consider the rdt3.0 protocol. Draw a diagram showing that if the network connectionbetween the sender and receiver can reorder messages (that is, that two messagespropagating in the medium between the sender and receiver can be reordered), thenthe alternating-bit protocol will not work correctly (make sure you clearly identify thesense in which it will not work correctly). Your diagram should have the sender on theleft and the receiver on the right, with the time axis running down the page, showingdata (D) and acknowledgement (A) message exchange. Make sure you indicate thesequence number associated with any data or acknowledgement segment.Answer:15. (P12) The sender side of rdt3.0 simply ignores (that is, takes no action on) all received packetsthat are either in error or have the wrong value in the ack-num field of anacknowledgement packet. Suppose that in such circumstances, rdt3.0 were simply toretransmit the current data packet . Would the protocol still work? (hint: Consider whatwould happen if there were only bit errors; there are no packet losses but prematuretimeout can occur. Consider how many times the nth packet is sent, in the limit as napproaches infinity.)Answer:The protocol would still work, since a retransmission would be what would happen if the packet received with errors has actually been lost (and from the receiver standpoint, it never knows which of these events, if either, will occur). To get at the more subtle issue behind this question, one has to allow for premature timeouts to occur. In this case, if each extra copy of the packet is ACKed and each received extra ACK causes another extra copy of the current packet to be sent, the number of times packet n is sent will increase without bound as n approaches infinity.16. (P13) Consider a reliable data transfer protocol that uses only negative acknowledgements.Suppose the sender sends data only infrequently. Would a NAK-only protocol bepreferable to a protocol that uses ACKs? Why? Now suppose the sender has a lot ofdata to send and the end to end connection experiences few losses. In this second case ,would a NAK-only protocol be preferable to a protocol that uses ACKs? Why?Answer:In a NAK only protocol, the loss of packet x is only detected by the receiver when packetx+1 is received. That is, the receivers receives x-1 and then x+1, only when x+1 is received does the receiver realize that x was missed. If there is a long delay between the transmission of x and the transmission of x+1, then it will be a long time until x can be recovered, under a NAK only protocol.On the other hand, if data is being sent often, then recovery under a NAK-only scheme could happen quickly. Moreover, if errors are infrequent, then NAKs are only occasionally sent (when needed), and ACK are never sent – a significant reduction in feedback in the NAK-only case over the ACK-only case.17. (P14) Consider the cross-country example shown in Figure 3.17. How big would the windowsize have to be for the channel utilization to be greater than 80 percent?Answer:It takes 8 microseconds (or 0.008 milliseconds) to send a packet. in order for the sender to be busy 90 percent of the time, we must have util = 0.9 = (0.008n) / 30.016 or n approximately 3377 packets.18. (P15) Consider a scenario in which Host A wants to simultaneously send packets to Host Band C. A is connected to B and C via a broadcast channel—a packet sent by A is carriedby the channel to both B and C. Suppose that the broadcast channel connecting A, B,and C can independently lose and corrupt packets (and so, for example, a packet sentfrom A might be correctly received by B, but not by C). Design a stop-and-wait-likeerror-control protocol for reliable transferring packets from A to B and C, such that Awill not get new data from the upper layer until it knows that B and C have correctlyreceived the current packet. Give FSM descriptions of A and C. (Hint: The FSM for Bshould be essentially be same as for C.) Also, give a description of the packet format(s)used.Answer:In our solution, the sender will wait until it receives an ACK for a pair of messages (seqnum and seqnum+1) before moving on to the next pair of messages. Data packets have a data field and carry a two-bit sequence number. That is, the valid sequence numbers are 0, 1, 2, and 3. (Note: you should think about why a 1-bit sequence number space of 0, 1 only would not work in the solution below.) ACK messages carry the sequence number of the data packet they are acknowledging.The FSM for the sender and receiver are shown in Figure 2. Note that the sender state records whether (i) no ACKs have been received for the current pair, (ii) an ACK for seqnum (only) has been received, or an ACK for seqnum+1 (only) has been received. In this figure, we assume that theseqnum is initially 0, and that the sender has sent the first two data messages (to get things going).A timeline trace for the sender and receiver recovering from a lost packet is shown below:Sender Receivermake pair (0,1)send packet 0Packet 0 dropssend packet 1receive packet 1buffer packet 1send ACK 1receive ACK 1(timeout)resend packet 0receive packet 0deliver pair (0,1)send ACK 0receive ACK 019. (P16) Consider a scenario in which Host A and Host B want to send messages to Host C. HostsA and C are connected by a channel that can lose and corrupt (but not reorder)message.Hosts B and C are connected by another channel (independent of the channelconnecting A and C) with the same properties. The transport layer at Host C shouldalternate in delivering messages from A and B to the layer above (that is, it should firstdeliver the data from a packet from A, then the data from a packet from B, and so on).Design a stop-and-wait-like error-control protocol for reliable transferring packets fromA toB and C, with alternating delivery atC as described above. Give FSM descriptionsof A and C. (Hint: The FSM for B should be essentially be same as for A.) Also, give adescription of the packet format(s) used.Answer:This problem is a variation on the simple stop and wait protocol (rdt3.0). Because the channel may lose messages and because the sender may resend a message that one of the receivers has already received (either because of a premature timeout or because the other receiver has yet to receive the data correctly), sequence numbers are needed. As in rdt3.0, a 0-bit sequence number will suffice here.The sender and receiver FSM are shown in Figure 3. In this problem, the sender state indicates whether the sender has received an ACK from B (only), from C (only) or from neither C nor B. The receiver state indicates which sequence number the receiver is waiting for.20. (P17) In the generic SR protocol that we studied in Section 3.4.4, the sender transmits amessage as soon as it is available (if it is in the window) without waiting for anacknowledgment. Suppose now that we want an SR protocol that sends messages twoat a time. That is , the sender will send a pair of messages and will send the next pairof messages only when it knows that both messages in the first pair have been receivercorrectly.Suppose that the channel may lose messages but will not corrupt or reorder messages.Design an error-control protocol for the unidirectional reliable transfer of messages.Give an FSM description of the sender and receiver. Describe the format of the packetssent between sender and receiver, and vice versa. If you use any procedure calls otherthan those in Section 3.4(for example, udt_send(), start_timer(), rdt_rcv(), and soon) ,clearly state their actions. Give an example (a timeline trace of sender and receiver)showing how your protocol recovers from a lost packet.Answer:21. (P18) Consider the GBN protocol with a sender window size of 3 and a sequence numberrange of 1024. Suppose that at time t, the next in-order packet that the receiver isexpecting has a sequence number of k. Assume that the medium does not reordermessages. Answer the following questions:a. What are the possible sets of sequence number inside the sender’s window at timet? Justify your Answer.b .What are all possible values of the ACK field in all possible messages currentlypropagating back to the sender at time t? Justify your Answer.Answer:a.Here we have a window size of N=3. Suppose the receiver has received packet k-1, and hasACKed that and all other preceeding packets. If all of these ACK's have been received by sender, then sender's window is [k, k+N-1]. Suppose next that none of the ACKs have been received at the sender. In this second case, the sender's window contains k-1 and the N packets up to and including k-1. The sender's window is thus [k- N,k-1]. By these arguments, the senders window is of size 3 and begins somewhere in the range [k-N,k].b.If the receiver is waiting for packet k, then it has received (and ACKed) packet k-1 and the N-1packets before that. If none of those N ACKs have been yet received by the sender, then ACKmessages with values of [k-N,k-1] may still be propagating back. Because the sender has sent packets [k-N, k-1], it must be the case that the sender has already received an ACK for k-N-1.Once the receiver has sent an ACK for k-N-1 it will never send an ACK that is less that k-N-1.Thus the range of in-flight ACK values can range from k-N-1 to k-1.22. (P19) Answer true or false to the following questions and briefly justify your Answer.a. With the SR protocol, it is possible for the sender to receive an ACK for a packet thatfalls outside of its current window.b. With CBN, it is possible for the sender to receiver an ACK for a packet that fallsoutside of its current window.c. The alternating-bit protocol is the same as the SR protocol with a sender and receiverwindow size of 1.d. The alternating-bit protocol is the same as the GBN protocol with a sender andreceiver window size of 1.Answer:a.True. Suppose the sender has a window size of 3 and sends packets 1, 2, 3 at t0 . At t1 (t1 > t0)the receiver ACKS 1, 2, 3. At t2 (t2 > t1) the sender times out and resends 1, 2, 3. At t3 the receiver receives the duplicates and re-acknowledges 1, 2, 3. At t4 the sender receives the ACKs that the receiver sent at t1 and advances its window to 4, 5, 6. At t5 the sender receives the ACKs 1, 2, 3 the receiver sent at t2 . These ACKs are outside its window.b.True. By essentially the same scenario as in (a).c.True.d.True. Note that with a window size of 1, SR, GBN, and the alternating bit protocol arefunctionally equivalent. The window size of 1 precludes the possibility of out-of-order packets (within the window). A cumulative ACK is just an ordinary ACK in this situation, since it can only refer to the single packet within the window.23. (Q4) Why is it that voice and video traffic is often sent over TCP rather than UDP in today’sInternet. (Hint: The Answer we are looking for has nothing to do with TCP’s congestion-control mechanism. )Answer:Since most firewalls are configured to block UDP traffic, using TCP for video and voice traffic lets the traffic though the firewalls24. (Q5) Is it possible for an application to enjoy reliable data transfer even when the applicationruns over UDP? If so, how?Answer:Yes. The application developer can put reliable data transfer into the application layer protocol. This would require a significant amount of work and debugging, however.25. (Q6) Consider a TCP connection between Host A and Host B. Suppose that the TCP segmentstraveling form Host A to Host B have source port number x and destination portnumber y. What are the source and destination port number for the segments travelingform Host B to Host A?Answer:Source port number y and destination port number x.26. (P20) Suppose we have two network entities, A and B. B has a supply of data messages thatwill be sent to A according to the following conventions. When A gets a request fromthe layer above to get the next data (D) message from B, A must send a request (R)message to B on the A-to-B channel. Only when B receives an R message can it send adata (D) message back to A on the B-to-A channel. A should deliver exactly one copy ofeach D message to the layer above. R message can be lost (but not corrupted) in the A-to-B channel; D messages, once sent, are always delivered correctly. The delay alongboth channels is unknown and variable.Design(give an FSM description of) a protocol that incorporates the appropriatemechanisms to compensate for the loss-prone A-to-B channel and implementsmessage passing to the layer above at entity A, as discussed above. Use only thosemechanisms that are absolutely necessary.Answer:Because the A-to-B channel can lose request messages, A will need to timeout and retransmit its request messages (to be able to recover from loss). Because the channel delays are variable and unknown, it is possible that A will send duplicate requests (i.e., resend a request message that has already been received by B). To be able to detect duplicate request messages, the protocol will use sequence numbers. A 1-bit sequence number will suffice for a stop-and-wait type of request/response protocol.A (the requestor) has 4 states:• “Wait for Request 0 from above.” Here the requestor is waiting for a call from above to request a unit of data. When it receives a request from above, it sends a request message, R0, to B, starts a timer and make s a transition to the “Wait for D0” state. When in the “Wait for Request 0 from above” state, A ign ores anything it receives from B.• “Wait for D0”. Here the requestor is waiting for a D0 data message from B. A timer is always running in this state. If the timer expires, A sends another R0 message, restarts the timer and remains in this state. If a D0 message is received from B, A stops the time and transits to the “Wait for Request 1 from above” state. If A receives a D1 data message while in this state, it is ignored.• “Wait for Request 1 from above.” Here the requestor is again waiting for a call from above to request a unit of data. When it receives a request from above, it sends a request message, R1, to B, starts a timer and makes a transition to the “Wait for D1” state. When in the “Wait for Request 1 from above” state, A ignores anything it receives from B.• “Wait for D1”. Here the requestor is waiting for a D1 data message from B. A timer is always running in this state. If the timer expires, A sends another R1 message, restarts the timer and remains in this state. If a D1 message is received from B, A stops the timer and transits to the “Wait for Request 0 from above” state. If A receives a D0 data message while in this state, it is ignored.The data supplier (B) has only two states:。
《管理学》(Management)(英文大纲)
Part 2 Defining the Manager’s Terrain
Chapter 3 Organizational Culture and the Environment: The Constraints
The manager: Omnipotent or Symbolic? The organization’s Culture The environment
Part 6 Controlling
Chapter 18 Foundations of Control
What is control? Why is control important? The control process Types of control Implications for managers Contemporary issues in control
The importance of strategic management The strategic management process Types of organizational strategies
Part 3 Planning(Cont’d)
Chapter 9 Planning Tools and Techniques
Understanding managerial communication The process of interpersonal
communication Organizational communication Understanding information technology
Part 6 Controlling(Cont’d)
Chapter 19 Operations and Value Chain Management
________________________________________________ Session S3C MINORITY ENGINEERING PROGRAM C
________________________________________________ 1Joseph E. Urban, Arizona State University, Department of Computer Science and Engineering, P.O. Box 875406, Tempe, Arizona, 85287-5406, joseph.urban@ 2Maria A. Reyes, Arizona State University, College of Engineering and Applied Sciences, Po Box 874521, Tempe, Arizona 852189-955, maria@ 3Mary R. Anderson-Rowland, Arizona State University, College of Engineering and Applied Sciences, P.O. Box 875506, Tempe, Arizona 85287-5506, mary.Anderson@MINORITY ENGINEERING PROGRAM COMPUTER BASICS WITH AVISIONJoseph E. Urban 1, Maria A. Reyes 2, and Mary R. Anderson-Rowland 3Abstract - Basic computer skills are necessary for success in an undergraduate engineering degree program. Students who lack basic computer skills are immediately at risk when entering the university campus. This paper describes a one semester, one unit course that provided basic computer skills to minority engineering students during the Fall semester of 2001. Computer applications and software development were the primary topics covered in the course that are discussed in this paper. In addition, there is a description of the manner in which the course was conducted. The paper concludes with an evaluation of the effort and future directions.Index Terms - Minority, Freshmen, Computer SkillsI NTRODUCTIONEntering engineering freshmen are assumed to have basic computer skills. These skills include, at a minimum, word processing, sending and receiving emails, using spreadsheets, and accessing and searching the Internet. Some entering freshmen, however, have had little or no experience with computers. Their home did not have a computer and access to a computer at their school may have been very limited. Many of these students are underrepresented minority students. This situation provided the basis for the development of a unique course for minority engineering students. The pilot course described here represents a work in progress that helped enough of the students that there is a basis to continue to improve the course.It is well known that, in general, enrollment, retention, and graduation rates for underrepresented minority engineering students are lower than for others in engineering, computer science, and construction management. For this reason the Office of Minority Engineering Programs (OMEP, which includes the Minority Engineering Program (MEP) and the outreach program Mathematics, Engineering, Science Achievement (MESA)) in the College of Engineering and Applied Sciences (CEAS) at Arizona State University (ASU) was reestablished in 1993to increase the enrollment, retention, and graduation of these underrepresented minority students. Undergraduate underrepresented minority enrollment has increased from 400 students in Fall 1992 to 752 students in Fall 2001 [1]. Retention has also increased during this time, largely due to a highly successful Minority Engineering Bridge Program conducted for two weeks during the summer before matriculation to the college [2] - [4]. These Bridge students were further supported with a two-unit Academic Success class during their first semester. This class included study skills, time management, and concept building for their mathematics class [5]. The underrepresented minority students in the CEAS were also supported through student chapters of the American Indian Science and Engineering Society (AISES), the National Society of Black Engineers (NSBE), and the Society of Hispanic Professional Engineers (SHPE). The students received additional support from a model collaboration within the minority engineering student societies (CEMS) and later expanded to CEMS/SWE with the addition of the student chapter of the Society of Women Engineers (SWE) [6]. However, one problem still persisted: many of these same students found that they were lacking in the basic computer skills expected of them in the Introduction to Engineering course, as well as introductory computer science courses.Therefore, during the Fall 2001 Semester an MEP Computer Basics pilot course was offered. Nineteen underrepresented students took this one-unit course conducted weekly. Most of the students were also in the two-unit Academic Success class. The students, taught by a Computer Science professor, learned computer basics, including the sending and receiving of email, word processing, spreadsheets, sending files, algorithm development, design reviews, group communication, and web page development. The students were also given a vision of advanced computer science courses and engineering and of computing careers.An evaluation of the course was conducted through a short evaluation done by each of five teams at the end of each class, as well as the end of semester student evaluations of the course and the instructor. This paper describes theclass, the students, the course activities, and an assessment of the short-term overall success of the effort.M INORITY E NGINEERING P ROGRAMSThe OMEP works actively to recruit, to retain, and to graduate historically underrepresented students in the college. This is done through targeted programs in the K-12 system and at the university level [7], [8]. The retention aspects of the program are delivered through the Minority Engineering Program (MEP), which has a dedicated program coordinator. Although the focus of the retention initiatives is centered on the disciplines in engineering, the MEP works with retention initiatives and programs campus wide.The student’s efforts to work across disciplines and collaborate with other culturally based organizations give them the opportunity to work with their peers. At ASU the result was the creation of culturally based coalitions. Some of these coalitions include the American Indian Council, El Concilio – a coalition of Hispanic student organizations, and the Black & African Coalition. The students’ efforts are significant because they are mirrored at the program/staff level. As a result, significant collaboration of programs that serve minority students occurs bringing continuity to the students.It is through a collaboration effort that the MEP works closely with other campus programs that serve minority students such as: Math/Science Honors Program, Hispanic Mother/Daughter Program, Native American Achievement Program, Phoenix Union High School District Partnership Program, and the American Indian Institute. In particular, the MEP office had a focus on the retention and success of the Native American students in the College. This was due in large part to the outreach efforts of the OMEP, which are channeled through the MESA Program. The ASU MESA Program works very closely with constituents on the Navajo Nation and the San Carlos Apache Indian Reservation. It was through the MESA Program and working with the other campus support programs that the CEAS began investigating the success of the Native American students in the College. It was a discovery process that was not very positive. Through a cohort investigation that was initiated by the Associate Dean of Student Affairs, it was found that the retention rate of the Native American students in the CEAS was significantly lower than the rate of other minority populations within the College.In the spring of 2000, the OMEP and the CEAS Associate Dean of Student Affairs called a meeting with other Native American support programs from across the campus. In attendance were representatives from the American Indian Institute, the Native American Achievement Program, the Math/Science Honors Program, the Assistant Dean of Student Life, who works with the student coalitions, and the Counselor to the ASU President on American Indian Affairs, Peterson Zah. It was throughthis dialogue that many issues surrounding student success and retention were discussed. Although the issues andconcerns of each participant were very serious, the positiveeffect of the collaboration should be mentioned and noted. One of the many issues discussed was a general reality that ahigh number of Native American students were c oming to the university with minimal exposure to technology. Even through the efforts in the MESA program to expose studentsto technology and related careers, in most cases the schoolsin their local areas either lacked connectivity or basic hardware. In other cases, where students had availability to technology, they lacked teachers with the skills to help them in their endeavors to learn about it. Some students were entering the university with the intention to purse degrees in the Science, Technology, Engineering, and Mathematics (STEM) areas, but were ill prepared in the skills to utilize technology as a tool. This was particularly disturbing in the areas of Computer Science and Computer Systems Engineering where the basic entry-level course expected students to have a general knowledge of computers and applications. The result was evident in the cohort study. Students were failing the entry-level courses of CSE 100 (Principals of Programming with C++) or CSE 110 (Principals of Programming with Java) and CSE 200 (Concepts of Computer Science) that has the equivalent of CSE 100 or CSE 110 as a prerequisite. The students were also reporting difficulty with ECE 100, (Introduction to Engineering Design) due to a lack of assumed computer skills. During the discussion, it became evident that assistance in the area of technology skill development would be of significance to some students in CEAS.The MEP had been offering a seminar course inAcademic Success – ASE 194. This two-credit coursecovered topics in study skills, personal development, academic culture issues and professional development. The course was targeted to historically underrepresented minority students who were in the CEAS [3]. It was proposed by the MEP and the Associate Dean of Student Affairs to add a one-credit option to the ASE 194 course that would focus entirely on preparing students in the use of technology.A C OMPUTERB ASICSC OURSEThe course, ASE 194 – MEP Computer Basics, was offered during the Fall 2001 semester as a one-unit class that met on Friday afternoons from 3:40 pm to 4:30 pm. The course was originally intended for entering computer science students who had little or no background using computer applications or developing computer programs. However, enrollment was open to non-computer science students who subsequently took advantage of the opportunity. The course was offered in a computer-mediated classroom, which meantthat lectures, in- class activities, and examinations could all be administered on comp uters.During course development prior to the start of the semester, the faculty member did some analysis of existing courses at other universities that are used by students to assimilate computing technology. In addition, he did a review of the comp uter applications that were expected of the students in the courses found in most freshman engineering programs.The weekly class meetings consisted of lectures, group quizzes, accessing computer applications, and group activities. The lectures covered hardware, software, and system topics with an emphasis on software development [9]. The primary goals of the course were twofold. Firstly, the students needed to achieve a familiarity with using the computer applications that would be expected in the freshman engineering courses. Secondly, the students were to get a vision of the type of activities that would be expected during the upper division courses in computer science and computer systems engineering and later in the computer industry.Initially, there were twenty-two students in the course, which consisted of sixteen freshmen, five sophomores, and one junior. One student, a nursing freshman, withdrew early on and never attended the course. Of the remaining twenty-one students, there were seven students who had no degree program preference; of which six students now are declared in engineering degree programs and the seventh student remains undecided. The degree programs of the twenty-one students after completion of the course are ten in the computing degree programs with four in computer science and six in computer systems engineering. The remaining nine students includes one student in social work, one student is not decided, and the rest are widely distributed over the College with two students in the civil engineering program and one student each in bioengineering, electrical engineering, industrial engineering, material science & engineering, and mechanical engineering.These student degree program demographics presented a challenge to maintain interest for the non-computing degree program students when covering the software development topics. Conversely, the computer science and computer systems engineering students needed motivation when covering applications. This balance was maintained for the most part by developing an understanding that each could help the other in the long run by working together.The computer applications covered during the semester included e-mail, word processing, web searching, and spreadsheets. The original plan included the use of databases, but that was not possible due to the time limitation of one hour per week. The software development aspects included discussion of software requirements through specification, design, coding, and testing. The emphasis was on algorithm development and design review. The course grade was composed of twenty-five percent each for homework, class participation, midterm examination, and final examination. An example of a homework assignment involved searching the web in a manner that was more complex than a simple search. In order to submit the assignment, each student just had to send an email message to the faculty member with the information requested below. The email message must be sent from a student email address so that a reply can be sent by email. Included in the body of the email message was to be an answer for each item below and the URLs that were used for determining each answer: expected high temperature in Centigrade on September 6, 2001 for Lafayette, LA; conversion of one US Dollar to Peruvian Nuevo Sols and then those converted Peruvian Nuevo Sols to Polish Zlotys and then those converted Polish Zlotys to US Dollars; birth date and birth place of the current US Secretary of State; between now and Thursday, September 6, 2001 at 5:00 pm the expected and actual arrival times for any US domestic flight that is not departing or arriving to Phoenix, AZ; and your favorite web site and why the web site is your favorite. With the exception of the favorite web site, each item required either multiple sites or multiple levels to search. The identification of the favorite web site was introduced for comparison purposes later in the semester.The midterm and final examinations were composed of problems that built on the in-class and homework activities. Both examinations required the use of computers in the classroom. The submission of a completed examination was much like the homework assignments as an e-mail message with attachments. This approach of electronic submission worked well for reinforcing the use of computers for course deliverables, date / time stamping of completed activities, and a means for delivering graded results. The current technology leaves much to be desired for marking up a document in the traditional sense of hand grading an assignment or examination. However, the students and faculty member worked well with this form of response. More importantly, a major problem occurred after the completion of the final examination. One of the students, through an accident, submitted the executable part of a browser as an attachment, which brought the e-mail system to such a degraded state that grading was impossible until the problem was corrected. An ftp drop box would be simple solution in order to avoid this type of accident in the future until another solution is found for the e-mail system.In order to get students to work together on various aspects of the course, there was a group quiz and assignment component that was added about midway through the course. The group activities did not count towards the final grade, however the students were promised an award for the group that scored the highest number of points.There were two group quizzes on algorithm development and one out-of-class group assignment. The assignment was a group effort in website development. This assignment involved the development of a website that instructs. The conceptual functionality the group selected for theassignment was to be described in a one-page typed double spaced written report by November 9, 2001. During the November 30, 2001 class, each group presented to the rest of the class a prototype of what the website would look like to the end user. The reports and prototypes were subject to approval and/or refinement. Group members were expected to perform at approximately an equal amount of effort. There were five groups with four members in four groups and three members in one group that were randomly determined in class. Each group had one or more students in the computer science or computer systems engineering degree programs.The three group activities were graded on a basis of one million points. This amount of points was interesting from the standpoint of understanding relative value. There was one group elated over earning 600,000 points on the first quiz until the group found out that was the lowest score. In searching for the group award, the faculty member sought a computer circuit board in order to retrieve chips for each member of the best group. During the search, a staff member pointed out another staff member who salvages computers for the College. This second staff member obtained defective parts for each student in the class. The result was that each m ember of the highest scoring group received a motherboard, in other words, most of the internals that form a complete PC. All the other students received central processing units. Although these “awards” were defective parts, the students viewed these items as display artifacts that could be kept throughout their careers.C OURSE E VALUATIONOn a weekly basis, there were small assessments that were made about the progress of the course. One student was selected from each team to answer three questions about the activities of the day: “What was the most important topic covered today?”, “What topic covered was the ‘muddiest’?”, and “About what topic would you like to know more?”, as well as the opportunity to provide “Other comments.” Typically, the muddiest topic was the one introduced at the end of a class period and to be later elaborated on in the next class. By collecting these evaluation each class period, the instructor was able to keep a pulse on the class, to answer questions, to elaborate on areas considered “muddy” by the students, and to discuss, as time allowed, topics about which the students wished to know more.The overall course evaluation was quite good. Nineteen of the 21 students completed a course evaluation. A five-point scale w as used to evaluate aspects of the course and the instructor. An A was “very good,” a B was “good,” a C was “fair,” a D was “poor,” and an E was “not applicable.” The mean ranking was 4.35 on the course. An average ranking of 4.57, the highest for the s even criteria on the course in general, was for “Testbook/ supplementary material in support of the course.” The “Definition and application of criteria for grading” received the next highest marks in the course category with an average of 4.44. The lowest evaluation of the seven criteria for the course was a 4.17 for “Value of assigned homework in support of the course topics.”The mean student ranking of the instructor was 4.47. Of the nine criteria for the instructor, the highest ranking of 4.89 was “The instructor exhibited enthusiasm for and interest in the subject.” Given the nature and purpose of this course, this is a very meaningful measure of the success of the course. “The instructor was well prepared” was also judged high with a mean rank of 4.67. Two other important aspects of this course, “The instructor’s approach stimulated student thinking” and “The instructor related course material to its application” were ranked at 4.56 and 4.50, respectively. The lowest average rank of 4.11 was for “The instructor or assistants were available for outside assistance.” The instructor keep posted office hours, but there was not an assistant for the course.The “Overall quality of the course and instruction” received an average rank of 4.39 and “How do you rate yourself as a student in this course?” received an average rank of 4.35. Only a few of the students responded to the number of hours per week that they studies for the course. All of the students reported attending at least 70% of the time and 75% of the students said that they attended over 90% of the time. The students’ estimate seemed to be accurate.A common comment from the student evaluations was that “the professor was a fun teacher, made class fun, and explained everything well.” A common complaint was that the class was taught late (3:40 to 4:30) on a Friday. Some students judged the class to be an easy class that taught some basics about computers; other students did not think that there was enough time to cover all o f the topics. These opposite reactions make sense when we recall that the students were a broad mix of degree programs and of basic computer abilities. Similarly, some students liked that the class projects “were not overwhelming,” while other students thought that there was too little time to learn too much and too much work was required for a one credit class. Several students expressed that they wished the course could have been longer because they wanted to learn more about the general topics in the course. The instructor was judged to be a good role model by the students. This matched the pleasure that the instructor had with this class. He thoroughly enjoyed working with the students.A SSESSMENTS A ND C ONCLUSIONSNear the end of the Spring 2002 semester, a follow-up survey that consisted of three questions was sent to the students from the Fall 2001 semester computer basics course. These questions were: “Which CSE course(s) wereyou enrolled in this semester?; How did ASE 194 - Computer Basi cs help you in your coursework this semester?; and What else should be covered that we did not cover in the course?”. There were eight students who responded to the follow-up survey. Only one of these eight students had enrolled in a CSE course. There was consistency that the computer basics course helped in terms of being able to use computer applications in courses, as well as understanding concepts of computing. Many of the students asked for shortcuts in using the word processing and spreadsheet applications. A more detailed analysis of the survey results will be used for enhancements to the next offering of the computer basics course. During the Spring 2002 semester, there was another set of eight students from the Fall 2001 semester computer basi cs course who enrolled in one on the next possible computer science courses mentioned earlier, CSE 110 or CSE 200. The grade distribution among these students was one grade of A, four grades of B, two withdrawals, and one grade of D. The two withdrawals appear to be consistent with concerns in the other courses. The one grade of D was unique in that the student was enrolled in a CSE course concurrently with the computer basics course, contrary to the advice of the MEP program. Those students who were not enrolled in a computer science course during the Spring 2002 semester will be tracked through the future semesters. The results of the follow-up survey and computer science course grade analysis will provide a foundation for enhancements to the computer basics course that is planned to be offered again during the Fall 2002 semester.S UMMARY A ND F UTURE D IRECTIONSThis paper described a computer basics course. In general, the course was considered to be a success. The true evaluation of this course will be measured as we do follow-up studies of these students to determine how they fare in subsequent courses that require basic computer skills. Future offerings of the course are expected to address non-standard computing devices, such as robots as a means to inspire the students to excel in the computing field.R EFERENCES[1] Office of Institutional Analysis, Arizona State UniversityEnro llment Summary, Fall Semester , 1992-2001, Tempe,Arizona.[2] Reyes, Maria A., Gotes, Maria Amparo, McNeill, Barry,Anderson-Rowland, Mary R., “MEP Summer Bridge Program: A Model Curriculum Project,” 1999 Proceedings, American Society for Engineering Education, Charlotte, North Carolina, June 1999, CD-ROM, 8 pages.[3] Reyes, Maria A., Anderson-Rowland, Mary R., andMcCartney, Mary Ann, “Learning from our MinorityEngineering Students: Improving Retention,” 2000Proceedings, American Society for Engineering Education,St. Louis, Missouri, June 2000, Session 2470, CD-ROM, 10pages.[4] Adair, Jennifer K,, Reyes, Maria A., Anderson-Rowland,Mary R., McNeill, Barry W., “An Education/BusinessPartnership: ASU’s Minority Engineering Program and theTempe Chamber of Commerce,” 2001 Proceeding, AmericanSociety for Engineering Education, Albuquerque, NewMexico, June 2001, CD-ROM, 9 pages.[5] Adair, Jennifer K., Reyes, Maria A., Anderson-Rowland,Mary R., Kouris, Demitris A., “Workshops vs. Tutoring:How ASU’s Minority Engineering Program is Changing theWay Engineering Students Learn, “ Frontiers in Education’01 Conference Proceedings, Reno, Nevada, October 2001,CD-ROM, pp. T4G-7 – T4G-11.[6] Reyes, Maria A., Anderson-Rowland, Mary R., Fletcher,Shawna L., and McCartney, Mary Ann, “ModelCollaboration within Minority Engineering StudentSocieties,” 2000 Proceedings, American Society forEngineering Education, St. Louis, Missouri, June 2000, CD-ROM, 8 pages.[7] Anderson-Rowland, Mary R., Blaisdell, Stephanie L.,Fletcher, Shawna, Fussell, Peggy A., Jordan, Cathryne,McCartney, Mary Ann, Reyes, Maria A., and White, Mary,“A Comprehensive Programmatic Approach to Recruitmentand Retention in the College of Engineering and AppliedSciences,” Frontiers in Education ’99 ConferenceProceedings, San Juan, Puerto Rico, November 1999, CD-ROM, pp. 12a7-6 – 12a7-13.[8] Anderson-Rowland, Mary R., Blaisdell, Stephanie L.,Fletcher, Shawna L., Fussell, Peggy A., McCartney, MaryAnn, Reyes, Maria A., and White, Mary Aleta, “ACollaborative Effort to Recruit and Retain UnderrepresentedEngineering Students,” Journal of Women and Minorities inScience and Engineering, vol.5, pp. 323-349, 1999.[9] Pfleeger, S. L., Software Engineering: Theory and Practice,Prentice-Hall, Inc., Upper Saddle River, NJ, 1998.。
文书の07000
2INSTALLATION PROCEDURE2.1 Installation............................................................... 2-22.2 Uninstallation .......................................................... 2-72.3 Reinstallation .......................................................... 2-9Analytical Solution Data Management System (INSTALLATION)2Analytical Solution Data Management System (INSTALLATION)Analytical Solution Data Management System (INSTALLATION) 2-1INSTALLATION PROCEDUREThe installation, uninstallation, upgrade, and reinstallation procedures for the Analytical Solution Data ManagementSystem are different. For each procedure, refer to the following appropriate chapters:● For new installationRefer to the following:Chapter 2. 2.1 InstallationChapter 3. 3.1 Preparation Required for Setup3.2 New SetupChapter 4. Database SettingsChapter 5. 5.1 Installation Qualification (IQ)● For uninstallationRefer to the following:Chapter 2. 2.2 Uninstallation● For troubleshootingRefer to the following:Chapter 2. 2.3 ReinstallationChapter 3. 3.1 Preparation Required for Setup3.3 Setup for Upgrade2-2 Analytical Solution Data Management System (INSTALLATION)I N S T A L L A T I O N P R O C E D U R E2.1 InstallationNOTICE: The customer must not attempt installation,uninstallation, or upgrade of the software. To insure safe and correct use of the instrument, itsinstallation must be carried out by, or under the supervision of, service personnel qualified by our authorized service agent or us.To install the Analytical Solution Data Management System, start Windows ® and log on to it using an administrator account. If Windows ® cannot start up normally or the login fails, refer to the user guide supplied with Windows ®.Install the Analytical Solution Data Management System as follows:(1) Close all the running applications and insert the installation CD into the CD drive.(2) In Windows ® Explorer, double-click the installer for theappropriate language version of theAnalytical Solution Data Management System under the CD drive.➢ ASDAMSInstaller_ EN.exe(3) If vcredist_x86.exe, the package required for the IQ tool, has not been installed, you are prompted to install the package. Click [Install].➢ If the package is already installed, skip to step (8)2.1 InstallationAnalytical Solution Data Management System (INSTALLATION) 2-3INSTALLATION PROCEDURE(4) The [User AccountControl] screen may appear.In such a case, click [Yes] to [Do you want to allow this app to make changes to your device?].(5) When the MicrosoftVisual C++ 2010 x86 Redistributable Setup screen appears, select the [I have read and accept the license terms.] check box and click [Install].(6) The packageinstallation starts.(7) When the installationis complete, the [Installation Is Complete] screen appears. Click [Finish].(8) A setup screenappears. Click [Next].Click [Ignore] button if the screen of "Files in Use" show during the setup.2-4 Analytical Solution Data Management System (INSTALLATION)I N S T A L L A T I O N P R O C E D U R E(9) The [SelectInstallation Folder] screen appears. Click [Disk Cost].(10) The disk spacescreen appears. Check [Available] (free space) and [Required](required space). Make sure that the disk has enough space and click [OK].The [Select Installation Folder] screen appears again. Proceed to the next step without changing the default setting (Folder: C:\ASDAMS).Select [Everyone] for whom the system is installed, and click [Next].☝The software must be installed in C: drive.☝1.5 TB or more of free space for ChromAssist and ASDAMS(Server PC or Stand-alone PC) and 500 GB of free space for ChromAssist and ASDAMS (Client PC).☝If the disk space is not enough, stop the installation. Deleteunnecessary files to make enough space and retry installation.☝The user cannot specify files to install because they are automatically imported when the installer iscreated.Analytical Solution Data Management System (INSTALLATION) 2-5INSTALLATION PROCEDURE(11) The [ConfirmInstallation] screen appears. Click [Next].(12) The [User AccountControl] screen may appear.In such a case, click [Yes] to [Do you want to allow this app from anunknown publisher to make changes to your device?].(13) The installationstarts.(14) When theinstallation is complete, the [InstallationComplete] screen appears. Click [Close].☞ If the installation cannot becomplete, refer to Troubleshooting.2-6Analytical Solution Data Management System (INSTALLATION)I N S T A L L A T I O N P R O C E D U R E(15) Right-click the[Start] button and click [Task Manager] from the displayed menu.(16) The [Task Manager]screen appears. Click [More details] to display [Services].(17) The [Services] list is displayed. Check [ASDAMSService].(18) [ASDAMSService] isincluded in [Services], the installation is complete.Proceed to Chapter 3, "Setting Each User Environment".[END]Analytical Solution Data Management System (INSTALLATION) 2-7INSTALLATION PROCEDURETo remove the Analytical Solution Data Management System installed on the Server and Client PC, perform uninstallation. To uninstall the Analytical Solution Data Management System, start Windows ® and log on to it using an administrator account. If Windows ® cannot start up normally or the login fails, refer to the user guide supplied with Windows ®.Uninstall the Analytical Solution Data Management System using the Windows ® function as follows:Make sure that Analytical Solution Data Management System is closed before uninstallation.(1) Right-click the [Start]button and click [Apps & features]from the displayedmenu.(2) The [Apps &features] screenappears. Click theAnalytical Solution Data Management System first and then [Uninstall].(3) A confirmationmessage appears.Click [Uninstall].(4) The [User AccountControl] screen may appear. In such a case, click [Yes] to [Do you want to allow this app from anunknown publisher to make changes to your device?].2-8 Analytical Solution Data Management System (INSTALLATION)I N S T A L L A T I O N P R O C E D U R E(5) When the screen toselect whether to continue the uninstallation appears, select[Automatically close applications and attempt to restart them after setup is complete.] and click [OK].(6) The uninstallationstarts.(7) Right-click the [Start]button and click [Apps and features] from the displayed menu.(8) If the AnalyticalSolution DataManagement System is not found in [Apps and features], the uninstallation is complete.[END]☞ If the uninstallation cannotbe complete, refer to Troubleshooting.☝Even after uninstallation, files, such as log files, other than extracted files are not deleted.If they are unnecessary, delete them manually. When continuing the upgrade process, do not delete the remaining files.☝When the setup hasalready been performed, the Date and Time will be set as follows:Server: Client :Server PCThe settings will remain even if uninstallation is performed.Manually change them if necessary. For how to change the settings, refer to the user guideaccompanying Windows ®pursuant to the environment.INSTALLATION PROCEDURE 2.3 ReinstallationTo repair the Analytical Solution Data Management Systeminstalled on the Server and Client PC, perform reinstallation. Toreinstall the Analytical Solution Data Management System,start Windows® and log on to it using an administrator account.If Windows® cannot start up normally or the login fails, refer tothe user guide supplied with Windows®.Reinstall the Analytical Solution Data Management System asfollows:(1) Close all the runningapplications andinsert the installationCD into the CD drive.(2) In Windows®Explorer, double-clickthe installer for theappropriate languageversion of theAnalytical SolutionData ManagementSystem under the CDdrive.➢ASDAMSInstaller_EN.exe(3) Select [RepairAnalytical InformationManagementSystem] and click[Finish].(4) The [User AccountControl] screen mayappear.In such a case, click[Yes] to [Do you wantto allow this app froman unknown publisherto make changes toyour device?].☝If you have an old versionof the Analytical SolutionData Management Systeminstalled, uninstall the oldversion before installing thenew version.2.3 ReinstallationAnalytical Solution Data Management System (INSTALLATION)2-92-10 Analytical Solution Data Management System (INSTALLATION)I N S T A L L A T I O N P R O C E D U R E(5) The screen to selectwhether to continue the reinstallation appears. Click [Continue].(6) The reinstallationstarts.(7) When thereinstallation is complete, a dialog box appears. Click [Close].(8) The screenprompting you to restart the PC appears. Close all the other applications and click [Yes].(9) The PC is restarted.(10) Click [More details]in [Task Manager] to display [Services]. If [ASDAMSService] is included in [Services], the installation is complete.Proceed to Chapter 3, "Setting Each User Environment". For a client PC, perform the settings in Chapter 4.3.2 too.[END]☞ If the reinstallation cannotbe complete, refer to Troubleshooting.If you do not restart the PC immediately, click [No].。
Building Embedded Linux Systems
Building Embedded Linux Systems（构件嵌入式Linux系统）By Karim YaghmourOrganization of the Material材料的组织There are three major parts to this book. The first part is composed of Chapter 1 through Chapter 3. These chapters cover the preliminary background required for building any sort of embedded Linux system. Though they describe no hands-on procedures, they are essential to understand many aspects of building embedded Linux systems.有这本书的三个部分。
第一部分是1章主要通过3章。
这些章节涵盖建筑任何嵌入式Linux 系统所需的初步背景。
虽然他们没有动手程序描述，他们了解嵌入式Linux系统的建设必不可少的许多方面。
The second part spans Chapter 4 through Chapter 9. These important chapters lay out the essential steps involved in building any embedded Linux system. Regardless of your systems' purpose or functionality, these chapters are required reading.第二部分跨越4章通过9章。
这些重要的章节奠定了嵌入式Linux系统建设所涉及的任何必要的步骤。
1+x大数据试题+参考答案
1+x大数据试题+参考答案一、单选题（共80题，每题1分，共80分）1、关于Sqoop数据的导入导出描述不正确的是？（）A、实现从MySQL到Hive的导入导出B、实现从MySQL到Oracle的导入导出C、实现从HDFS到Oracle的导入导出D、实现从HDFS到MySQL的导入导出正确答案：B2、关于ZooKeeper临时节点的说法正确的是？（）A、创建临时节点的命令为：create -s /tmp myvalueB、临时节点允许有子节点C、一旦会话结束，临时节点将被自动删除D、临时节点不能手动删除正确答案：C3、下列关于调度器的描述不正确的是？（）A、先进先出调度器可以是多队列B、容器调度器其实是多个FIFO队列C、公平调度器不允许管理员为每个队列单独设置调度策略D、先进先出调度器以集群资源独占的方式运行作业正确答案：A4、Hive 适合（）环境A、Hive 适合关系型数据环境B、Hive 适合用于联机(online)事务处理C、适合应用在大量不可变数据的批处理作业D、提供实时查询功能正确答案：C5、下列哪些不是 ZooKeeper 的特点（）A、可靠性B、顺序一致性C、多样系统映像D、原子性正确答案：C6、tar 命令用于对文件进行打包压缩或解压，-t 参数含义（）A、查看压缩包内有哪些文件B、创建压缩文件C、向压缩归档末尾追加文件D、解开压缩文件正确答案：A7、下列哪些不是 HBase 的特点（）A、高可靠性B、高性能C、面向列D、紧密性正确答案：D8、把公钥追加到授权文件的命令是？（）A、ssh-addB、ssh-copy-idC、ssh-keygenD、ssh正确答案：B9、HDFS有一个gzip文件大小75MB，客户端设置Block大小为64MB。
当运行mapreduce任务读取该文件时input split大小为？A、64MBB、75MBC、一个map读取64MB，另外一个map读取11MB正确答案：B10、大数据平台实施方案流程中,建议整个项目过程顺序是（）。
询问领导意见的英文句子-概述说明以及解释
询问领导意见的英文句子1.What is your opinion on this matter?2.Could you please share your thoughts on this issue?3.I would like to hear your perspective on this topic.4.May I ask for your feedback on this proposal?5.What do you think about this idea?6.Do you have any insights on this matter?7.Would you be able to provide your input on this decision?8.I value your opinion and would like to hear your thoughts.9.Could I get your point of view on this matter?10.Your feedback would be greatly appreciated.11.I'm curious to know your thoughts on this subject.12.Could you offer any suggestions on this issue?13.What are your impressions of this concept?14.Do you have any concerns or objections regarding this proposal?15.I would love to get your take on this matter.16.May I seek your guidance on this matter?17.What is your stance on this topic?18.Can I ask for your advice on this decision?19.How do you feel about this idea?20.Your perspective on this issue would be valuable.21.What is your take on this matter?22.Could you share your insights on this?23.I would appreciate your feedback on this issue.24.What are your thoughts on this particular situation?25.May I ask for your opinion on this matter?26.I value your perspective, would you mind giving me your input on this?27.How do you see this situation? Any suggestions?28.Are there any specific recommendations you can provide regarding this issue?29.Do you have any ideas or suggestions on how to approach this?30.I would like to hear your viewpoint on this topic.31.Can you offer any guidance or recommendations on this matter?32.What is your stance on this issue?33.I would be interested to know your viewpoint on this matter.34.Any advice or suggestions on how to proceed with this?35.What are your thoughts regarding the best course of action in this situation?36.May I seek your opinion on this matter?37.I would be grateful for your input on this particular issue.38.Do you have any recommendations on how to handle this?39.How do you perceive this situation? Any suggestions?40.What advice or suggestions would you offer in this scenario?41.What is your opinion on this matter?42.I value your input. What do you think about this?43.Could you share your thoughts on this issue?44.May I ask for your perspective on this?45.What are your views on this topic?46.Do you have any suggestions or insights regarding this?47.I would appreciate your feedback on this matter.48.Could you please provide your thoughts on this?49.Your expertise would be valuable. How do you see this situation?50.I'm interested in hearing your ideas on this. What are your thoughts?51.What is your take on this issue?52.Would you mind sharing your opinion on this?53.I would like to hear your viewpoint on this matter.54.What are your impressions regarding this topic?55.I'm curious to know what you think about this.56.Do you have any thoughts or suggestions on this?57.What would be your suggestion in this situation?58.How do you think we should proceed in this matter?59.Your perspective on this would be greatly appreciated.60.May I seek your guidance on this matter?61.Have you considered any alternative strategies?62.What do you think about incorporating customer feedback into our decision-making process?63.Are there any additional resources or support we need to obtain for this project?64.Do you believe our current approach aligns with ourlong-term goals?65.Would it be beneficial to seek input from other departments or teams?66.Are there any potential risks or challenges that need to be addressed?67.What are your thoughts on collaborating with external partners for this initiative?68.Do you think it is necessary to conduct a market research study before proceeding?69.How would you prioritize the various aspects of this project?70.What metrics should we use to measure the success of this endeavor?71.Do you have any concerns about the proposed budget forthis project?72.What would be your recommendation regarding the timeline for implementation?73.Should we involve key stakeholders in the decision-making process?74.What impact do you think this initiative will have on our existing operations?75.Do you have any reservations or doubts about the feasibility of this plan?76.How do you envision this project aligning with our company's values and mission?77.What do you think is the level of support we can expect from our team members?78.Do you believe additional training or skill development is necessary for the team?79.Should we consider reallocating resources from other projects to support this endeavor?80.What are your thoughts on conducting a pilot test before fully implementing the strategy?81.May I know your thoughts on this matter?82.What is your opinion on this issue?83.Could you please share your viewpoint on this?84.I would greatly appreciate your input on this subject.85.Do you have any suggestions regarding this matter?86.Could you kindly provide your thoughts on this?87.Would you mind sharing your perspective on this?88.I value your insights on this topic.89.I would like to hear your feedback on this.90.Your thoughts on this would be highly valuable.91.May I get your take on this?92.What are your views on this matter?93.Do you have any thoughts or ideas on this?94.Could you please give me your thoughts?95.I am interested in hearing your opinion.96.Your expert advice on this would be greatly appreciated.97.I would be grateful if you could provide your input on this.98.What would be your recommendation regarding this issue?99.Could you please give me your perspective on this? 100.I would like to know your stance on this matter.101.Could you share your thoughts on this matter?102.What is your opinion regarding this issue?103.May I seek your input on this topic?104.I would greatly appreciate your insights on this matter. 105.Do you have any thoughts or opinions on this subject?106.Could you provide some guidance on this matter?107.What are your views on this particular issue?108.I'm interested in hearing your perspective on this topic.109.Can I get your point of view on this matter?110.What do you think about this situation?111.Do you have any suggestions or recommendations in this regard?112.I would like to know your thoughts on this matter.113.Could you please give me your opinion on this matter?114.I'd like to hear your thoughts on this particular issue.115.What is your take on this topic?116.Can you provide some input on this subject?117.May I ask for your advice on this matter?118.What are your thoughts on this specific issue?119.I'm curious to know your perspective on this subject.120.Can you share your insights on this particular topic?。
TOGAF 9.2 题库练习(Level 1及Level 2)-中培课程【】.
Level 2（Certified）
问题23
阅读案例回答问题： 你是某公司的首席架构师，该公司主要生产用于工业设备的滚珠轴承。他们制造业务，主要是在美国，德国和英国的几个城市。该公司历来允许各工厂推动自己的生产计划系统。每个工厂都有自己的定制物料需求计划，主生产计划，物料清单和车间控制系统。 通过"Just In Time"制造技术，能减少因过多库存和在制品造成的浪费。竞争日益激烈的商业环境迫使企业改善其业务能力，以更好适应客户的需求。为进一步提升这种能力，该公司已经决定实施企业资源计划（ERP）解决方案，使它与其制造能力更好地匹配，满足产品需求。此外，在未来的六个月内，他们的制造过程必须加以调整以符合即将出台的欧洲新法规。作为实施过程的重要组成部分，企业架构（EA）部门已经开始实施基于TOGAF9的架构过程。CIO是活动的发起人。首席架构师已指示，该计划应包括使用架构内容框架和TOGAF的元模型内容的正式建模。这有助于公司使用架构工具支持其架构过程。首席架构师表示，为了模拟复杂的制造过程，有必要对事件驱动进行流程建模。此外，为了整合多个数据中心的应用程序，有必要针对IT资产的位置进行建模。特别是，最终的目标是单一的ERP应用程序运行在一个数据中心。目前该项目处于初步阶段，架构师正在剪裁架构开发方法（ADM）和架构内容框架，以适应企业环境。
D. 你应该建议架构团队将数据和服务扩展纳入到他们定制的内容元模型中，使他们能够针对IT资产的位置建模，并确保制造流程的合规性。这有助于识别那些在单一数据中心的整合过程中过剩的能力。
2021/9/15
Байду номын сангаасevel 2（Certified）
问题24阅读案例回答问题：你是汽车行业的一家主要供应商的首席企业架构师。该公司总部设在美国俄亥俄州克里夫兰市，在美国，巴西，德国，日本和韩国都有制造工厂。这些工厂一直运营着自己的生产计划和调度系统，以及定制开发的用以驱动自动化生产设备的应用程序。该公司正在实施精益制造原则，以减少浪费，在所有生产业务方面提高工作效率。最近举行的一次内部质量改进演习表明，通过替换位于克利夫兰数据中心的生产计划和调度系统的系统，生产浪费能显著减少。该中央系统能为每一个工厂更换现有系统的功能提供支持。它也能消除每个厂房设施都必须有独立完整的数据中心的需求。 节省出来的IT人员用来可以支持其它的应用程序。在某些情况下，一个第三方承包商能够提供这些员工。几年来，企业架构部门已经拥有基于TOGAF 9的成熟而且完善的治理架构和开发流程。在最近的一次会议上，架构委员会批准了一项来自负责全球制造业务的总工程师的架构工作请求。 请求涵盖了最初的架构调查和一个用来规划转型的全面体系结构的发展。目前，通用的ERP部署架构项目组已经形成，项目组已被要求制定一个架构愿景，以期达到预期的成果和收益。有些工厂经理对远程集中系统的实施计划和生产调度的安全性和可靠性都比较关注。总工程师想知道这些问题如何能得到解决。请参考情景：在通用ERP部署架构项目组的启动会议上，针对如何开展工作，项目组的成员提出了一些可供选择的方案。你需要选择最合适的建议，以确保项目组能针对问题评估不同的方案，并阐明架构的需求。基于TOGAF9 ，下列哪项是最佳答案？A.项目组应为每个制造工厂制定基线和目标架构，以确保与被选择的观点相对应的视图能解决干系人关注的核心问题。针对几个架构的综合对比分析，被用来验证方案，并确定实现目标要求所需的能力增量。B.项目组应该谨慎处理，并仔细研究厂商的文献，并和目前批准的供应商举行一系列的简报会。基于研究结果，项目组应该定义一个初步的架构愿景。然后，项目组根据它构建模型，和重要干系人达成共识。C. 项目组应针对干系人进行分析，以了解他们真正关注的问题。然后，利用业务场景技术，对每家制造工厂进行一系列的访谈。这将帮助他们识别和记录高层干系人对架构的关键需求。D. 项目组应推行一个试点项目，使候选人名单的厂商能演示能解决干系人所关注问题的各种解决方案。根据该试点项目的结果，可以开发出一套完整的退出机制，推动该架构的自我进化。
绿色生活绿意的英语作文
Living a green lifestyle has become increasingly important in todays world as we face the challenges of climate change,environmental degradation,and resource scarcity. Here are some key aspects to consider when writing an essay on living a green life:1.Reduce,Reuse,Recycle:The three Rs are the foundation of a green lifestyle.Reducing waste by consuming less,reusing items to extend their life,and recycling materials to prevent them from ending up in landfills.2.Sustainable Transportation:Opt for ecofriendly modes of transportation such as walking,biking,public transit,or carpooling to reduce carbon emissions.3.Energy Efficiency:Use energyefficient appliances and light bulbs,and consider renewable energy sources like solar or wind power for your home.4.Water Conservation:Save water by taking shorter showers,fixing leaks,and using watersaving devices.5.EcoFriendly Products:Choose products made from sustainable materials and with minimal packaging.Support companies that prioritize environmental responsibility.6.Local and Organic Food:Support local farmers by purchasing locally grown,organic produce.This reduces the carbon footprint associated with transportation and supports healthier agricultural practices.7.Planting Trees and Green Spaces:Engage in activities that increase green spaces,such as planting trees and maintaining gardens.This helps improve air quality and provides habitats for wildlife.8.Waste Management:Properly dispose of hazardous waste and compost organic materials to reduce the amount of waste that goes to landfills.cating Others:Raise awareness about the importance of a green lifestyle and encourage others to adopt ecofriendly practices.10.Policy Advocacy:Support and advocate for policies that promote environmental protection and sustainable development.11.Sustainable Fashion:Choose clothing made from sustainable materials and support brands that prioritize ethical production practices.12.Mindful Consumption:Be conscious of the impact of your purchases and make choices that align with your values of sustainability.munity Involvement:Participate in community cleanups,tree planting events, and other environmental initiatives to make a collective impact.14.Green Building:If youre in a position to do so,consider building or retrofitting your home with green building principles that focus on energy efficiency,sustainable materials, and reducing environmental impact.15.Personal Commitment:Make a personal commitment to live a greener life and continuously seek ways to improve your environmental footprint.By incorporating these elements into your essay,you can provide a comprehensive view of what it means to live a green life and the benefits it brings to both the individual and the planet.。
Eaton Visual Power Manager OVF Appliance Installat
Visual Capacity Optimization Manager Visual Power ManagerOVF Appliance Installation GuideRelease 6.9.0January 2023EatonProprietary and Confidential/VCOMLEGAL NOTICECopyright © 1999–2022. Eaton All rights reserved. The contents of this document constitute valuable proprietary and confidential property of Eaton and are provided subject to specific obligations of confidentiality set forth in one or more binding legal agreements. Any use of this material is limited strictly to the uses specifically authorized in the applicable license agreement(s) pursuant to which such material has been furnished. Any use or disclosure of all or any part of this material not specifically authorized in writing by Eaton is strictly prohibited.Contact SupportFor your convenience Eaton provides one site where you can access the information that you need for our enterprise products. You can access the resources listed below by going tohttps:///login.•Online and telephone contact information for technical assistance and customer services •Product and documentation downloads•Other helpful resources appropriate for your productContentsContents (4)1. Installing the OVF (Appliance) (5)Resources for VPM and VPM Essential OVF (5)Resources for VCOM OVF (5)Before You Install the OVF (6)Licensing (6)URL (6)HTTP vs HTTPS (6)Steps to Install the OVF (7)Static IP (8)DHCP (9)Wait 5 Minutes Before Attempting ServerAdmin (9)2. Finish Configuration in the Server Admin tool (10)3. Server Ports (16)From 3D Client to Master Server (16)From Web Client to Master Server (16)From Master Server to Probe Server (Distributed Setup) (16)From Master Server to Master DB (Distributed Setup) (16)From Master DB to Master Server (Distributed Setup) (16)From Master DB to Probe Servers (Distributed Setup) (16)From Probe Server to Master Server (Distributed Setup) (17)From Probe Server to Master DB (Distributed Setup) (17)From Probe Server to SNMP Monitored Devices (17)From SNMP Monitored Devices to Probe Server (17)From Probe Server to Modbus Monitored Devices (17)Internal Monitoring Ports on the Server (17)1.Installing the OVF (Appliance)Resources for VPM and VPM Essential OVFThe VPM and VPM Essential OVF has the following default resources to support approximately 1,000 Rackmount Assets (RMA) with a 5-minute poling interval.Operating System Oracle Linux 8.7 (64 bit)Disk Space 400 GBCPU 4 CPU (For the VCOM OVF it installed the Superset, it changes to 6CPU)It is strongly suggested that each VM host CPU/Core have a passmark rating of8000 or above: https:///cpu_list.phpMemory 16GB (For the VCOM OVF it installed the Superset, it change to 24GB) Database PostgreSQL 13.5 server (included with application)Web Server Tomcat 9.0.64 (included with application)Virtual Server VMware Workstation or ESXi 6.7 U2 and above with the Virtual HardwareVersion 15 formatResources for VCOM OVFThe VCOM OVF has the following default resources to support approximately 1,000 Rackmount Assets (RMA) with a 5-minute poling interval.Operating System Oracle Linux 8.7 (64 bit)Disk Space 400 GBCPU 6 CPUsIt is strongly suggested that each VM host CPU/Core have a passmark rating of8000 or above: https:///cpu_list.phpMemory 24GBDatabase PostgreSQL 13.5 server (included with application)Web Server Tomcat 9.0.64 (included with application)Virtual Server VMware Workstation or ESXi 6.7 U2 and above with the Virtual HardwareVersion 15 formatBefore You Install the OVFBefore you install the OVF please ensure you are prepared as to the items below.LicensingThere are two licensing options for your application. The application license uses hardware signature information.•Generic License –The generic license does not allow for vMotion on the VM. If the server moves with vMotion then the license will break. If you can turn off vMotion for your VM then use this license option.•vCenter (vMotion) License – If your VM has vMotion then you must use the vCenter license.o For the vCenter License you will need a▪IP Address for vCenter Server▪vCenter read-only service account▪Static password for service account (password cannot change)o How the vCenter License WorksTo protect Eaton product license against possible abuse in the virtualized environmentwith technologies, such as vMotion (for example, running multiple unauthorized VMcopies), it is necessary for our products to perform basic license validation with thefollowing 2 simple rules:1.In a vCenter environment, given a specific license, only one product instancewith that license is allowed to be running.2.The running product instance must match the IP, hostname and VM guest ID forwhich the license is issued.o The actual license validation algorithm is simple and straightforward:▪When the license is generated in a vCenter environment, the IP, hostname and VM guest ID is embedded in the license file which we issue for the customer.▪When running the application, our license validation method calls vCenter tocheck if there is one and only one IP + hostname + VM guest ID combinationexisting in vCenter that matches the specification in the license.▪Nothing else is read from vCenter other than the IP + hostname + VM GuestIDcombination. Typically, this has not been a security concern.URLYou will need a unique DNS qualified URL for the new server. When prompted enter the complete URL minus http/https.HTTP vs HTTPSIf you are going to use HTTPS follow the steps for Self-Sign.If desired, you can generate your own certificates at a later time.Steps to Install the OVFDownload OVF zip packageUnzip the package and import OVF to your VM Infrastructure using all of the files from the packageNOTE: BEFORE BOOTING THE VIRTUAL MACHINE, PLEASE MAKE SURE YOU HAVE A RESERVERD OR STATIC IP FOR THIS VM AND ALSO A DNS ENTRY CREATED FOR THE WEB URL YOU WOULD LIKE TO USE TO ACCESS THE APPLICATION WEB INTERFACE. THESE ARE HARD REQUIREMENTS AND BOTH WILL BE APPLIED DURING THE NEXT STEPS OF THE INSTALLATION WIZARD.Start your VM Guest server which is running the application. Do not add or remove a network interface to the VM Guest prior to startup.1.If the machine is slow, you may see this message. Click the Enter key to continue with theinitialization process.2.If the VM Host renames the network interface, then this message may appear. If you see thismessage, then hit Enter to continue with the initialization process.Choose an IP Configuration from the Network IP Address Configuration Menua.Static IP – Configure the VM Guest with a Static IP Addressb.DHCP – Use DHCP to dynamically assign an IP Address to the VM Guestc.Cancel – The Network IP Address Configuration Menu window will be closed, and theuser will be shown the OS login prompt.d.Reboot – The VM Guest will be rebooted.Static IP1.Enter the Static IP Address to be configured for the VM Guest2.Enter the network mask to be used for the Static IP Address3.Enter the gateway address to be used with the Static IP Address4.Enter the DNS Server to be used with the Static IP Address5.The configuration of the server will be updated based on the information provided. After 20-30seconds, the following message will be presented to the user. Access the URL specified andlogin with the user/password combination to continue with the initialization of the server.DHCPWhen the DHCP option is selected the configuration of the server will be updated. After 20-30 seconds, the following message will be presented to the user. Access the URL specified and login with theuser/password combination to continue with the initialization of the server.Wait 5 Minutes Before Attempting ServerAdminPlease wait 5 minutes before attempting to connect to the Server Admin tool to continue configuration.2.Finish Configuration in the Server Admin tooling a web browser application, access the https://IPAddress/ServerAdmin address which wasspecified in the IP Address Configuration message.e the admin / Monit@r#1 user/pw combination to login to this Server Admin interface.3.Server Admin will recognize the server has not been fully initialized and will present theinitialization screen. It needs to accept the Eula then will show the initialization steps page.4.Initialize page will auto disable SSH and firewall port.a.Disable SSH means user can’t access server by SSH command. Please click Enable SSH.b.Disable Firewall means server will close 12001-12006 ports. Please click Enable FirewallPort.5.Define the IP Address of the server – Dropdown list will display IP Address found on the serverautomatically.a.Note, the following message may appear and will require attention from the networkadministrator.6.Define the Host URL to be used to access the application.a.The system will preferentially retrieve the URL corresponding to the current IP from theDNS server. Note: we recommend users register IP and URL on the DNS server first.b.If the system cannot retrieve the URL from the DNS server, it will try to retrieve the URLfrom the application configuration file. The default URL is vcom680.local. In this case,the following message will appear, and users need to click Yes to continue.7.Define the Time zone to be used for the server8.Confirm the current time fields9.Click Submit to process configuration updates on the server and application.a.Note, if DNS does not have the specified URL registered, the following message willappear. Click OK to continue with the initialization process. You will need to registerthe specified URL with the DNS system to be able to access the application login pagewhen initialization is complete.b.Alternatively, the computer performing the installation may configure the localWindows hosts file with the IP and URL combination. This will allow the initializationprocess to complete, but end users would also need to configure hosts files to accessthe login page. Please make sure the URL is registered in the DNS system.10.The appl ication default it set to HTTPS Self Sign, if there are doesn’t want to change it, pleaseturn to step3. If want to change to HTTP or HTTPS Upload Certificate, please submit changes.After clicking the Submit, it will restart the server admin and it takes about 10 seconds. Please do not close the tab after it started it will show the server admin page.11.In the Initialization Window Step 3: Select License Type , click the radio button for GenericLicense and click Generate License Request button.12.For a vCenter license enter the following information in the fields shown below:- The IP address for the vCenter server- A read-only username and its Password for the vCenter server13.Click the Generate License Request buttonA message will appear which explains the need to obtain a license activation key for theapplication. Click OK and wait for the License Request File to be automatically downloaded to the laptop/PC and it can be found in the Downloads folder.14.Send the License Request File to the support team. The Support team will generate a LicenseActivation File which can be used for the application server.15.When the License Activation File has been received, use Step 4 of the Initialization web page onServer Admin to upload the license file. Use the Select File button to choose the LicenseActivation File. Click Upload License to apply the License Activation File to the server.16.The license will be applied to the server. Click OK to close the message window.17.The application of the license will require a reboot of the server and a full startup of theapplication and database processes. This process, depending on the speed of the server, can take up to 15 minutes to complete. A status message will indicate the license is being applied to the server.18.If the license is applied successfully, the browser session will be forwarded to the applicationlogin page. User will be presented the login page for the application.Login with user = admin and password = Monit@r#1 which is the default user for a newinstallation.a.The following error message will be received if the startup process fails. The mostcommon reason for this issue is related to resolving the specified URL to the IP Address of the server. Please ensure the DNS system is properly configured with the URL so the initialization process is able to complete the system startup processed.3.Server PortsThe application operates on multiple network ports to establish and maintain communication between server components and monitored devices. Customers must enable these ports during the setup of the server architecture for the system to operate as expected. The following summarizes the required ports in the application architecture.From 3D Client to Master Server# Port Type Port Port Usage1 TCP 80/443 Web Services2 TCP 12003 License Services3 TCP 12006 Message QueueFrom Web Client to Master Server# Port Type Port Port Usage1 TCP 80/443 Web ServerFrom Master Server to Probe Server (Distributed Setup)# Port Type Port Port Usage1 TCP 22 Remote Execution2 TCP 5432 DB Access3 TCP 12005 Remote MessagingFrom Master Server to Master DB (Distributed Setup)# Port Type Port Port Usage1 TCP 22 Remote Execution2 TCP 5432 DB Access if Master DB is on a separateserverFrom Master DB to Master Server (Distributed Setup)# Port Type Port Port Usage1 TCP 80/443 Web Services2 TCP 12007 Message QueueFrom Master DB to Probe Servers (Distributed Setup)1 TCP 5432 DB AccessFrom Probe Server to Master Server (Distributed Setup)# Port Type Port Port Usage1 TCP 80/443 Replication to access master services2 TCP 12006 Message Queue3 TCP 12007 Message Queue4 TCP 5432 DB Access if Master is an All-In-One orcombined with Master DB From Probe Server to Master DB (Distributed Setup)# Port Type Port Port Usage1 TCP 5432 DB Access if Master DB is on separate severFrom Probe Server to SNMP Monitored Devices# Port Type Port Port Usage1 UDP 161 SNMP QueryFrom SNMP Monitored Devices to Probe Server# Port Type Port Port Usage1 UDP 162 SNMP TrapsFrom Probe Server to Modbus Monitored Devices# Port Type Port Port Usage1 TCP 502 Modbus QueryInternal Monitoring Ports on the Server。
三次分配制度 英语
三次分配制度英语The three distribution systems, also known as three-part division of goods or three-way sharing system, originated in ancient China and have been practiced for over a thousand years. It is a unique and effective way to allocate resources fairly and provide stability within communities.The first part of the three distribution systems is "Equal Allocation". This principle ensures that everyone is given an equal share of the resources available. It promotes the idea of fairness and equal opportunity for all members of the society. Under this system, individuals receive an equal share of resources regardless of their contributions or needs. This ensures that no one is left behind or disadvantaged, and everyone has access to the basic necessities of life.The second part of the three distribution systems is "Equal Compensation". This principle emphasizes rewarding individuals based on their contributions to society. It acknowledges that individuals have different skills, talents, and efforts and therefore should be compensated accordingly. Those who contribute more to society or work harder receive a higher compensation compared to others. This motivates individuals to work diligently and make meaningful contributions to their communities.The third part of the three distribution systems is "According to Needs". This principle recognizes that individuals have different needs and circumstances, and resources should be allocated based on those needs. It takes into account factors such as age, health, disability, and family circumstances when distributing goods andresources. Individuals with greater needs receive more resources to support their well-being, while those with fewer needs receive fewer resources. This ensures that vulnerable members of society are taken care of and everyone's basic needs are met.The three distribution systems have played a vital role in Chinese society throughout history. They have contributed to social stability, harmonious relationships, and the overall welfare of the community. The systems promote a sense of equality, justice, and empathy among the members of society.One of the key advantages of the three distribution systems is that they minimize social inequalities. By providing equal access to resources, compensating individuals based on their contributions, and considering individual needs, the system reduces disparities in wealth and opportunities. It prevents the concentration of wealth in the hands of a few and ensures a more equitable distribution of resources.Another benefit of the three distribution systems is that they promote social cohesion and mutual support. By recognizing individual needs and providing for those needs, the systems create a sense of solidarity and cooperation within the community. Individuals are more likely to help and support each other, leading to a stronger and more resilient society.Moreover, the three distribution systems take into account the different aspects of fairness. The equal allocation ensures equal treatment for all, the equal compensation rewards effort and contribution, and the allocation according to needs focuses onfairness based on individual circumstances. This comprehensive approach to fairness ensures that no one is left behind and encourages a sense of social justice and equality.However, critics argue that the three distribution systems can create dependency and discourage individual initiative and innovation. They claim that the equal allocation and according to needs aspects may disincentivize individuals from working hard or pursuing personal development. Additionally, the systems may not effectively address the changing needs and dynamics of a modern society.In conclusion, the three distribution systems have been an integral part of Chinese culture for centuries. They provide a comprehensive and balanced approach to resource allocation, focusing on equality, contribution-based rewards, and meeting individual needs. While they have their advantages, it is essential to adapt and modify these systems to address the challenges and realities of the modern world.。
M.Chapkin V.Obraztsov
m2max = m2 + m2 ? 2E E3 + 2p p3 ; 3
1
(2)
which is greater than or equal to m2 and on the other hand smaller than or equal to (m ? m3 )2. This means that the variable is more powerful than the commonly used m3 value. KORALZ 5] Monte Carlo shows that distribution on m2max when the Initial State Radiation (ISR) is switched o has form
Abstract
1 Introduction
The usual eld theory of microscopic process is invariant under the product of charge conjugations (C), space re ection (P) and time reversal (T). For this reason a test of CPT invariance is really a test of correctness of the description of the microscopic phenomena in terms of existing eld theory. CPT violation would mean an existence of unknown properties of the elds and their interactions which are outside the standard eld theory. The best known consequence of CPT invariance is the equality of masses and lifetimes of a particle and its antiparticle. The most impressive limit on mass di erence between particle and its antiparicle was obtained for the system (K 0; K 0). In the literature 1], the reader can meet the estimate j(mK0 ? mK0 )=mK0 j < 9 10?19, but it does not mean that the parameters describing CPT violation are extremely small too. The extraordinary smallness of this ratio originates from the factor 2(mK ? mK )=mK0 1:4 10?14 which has nothing to do with CPT violation and the ratio is also not independent of some approximations and theoretical assumptions ( see also ref. 2]). It is more natural to look for CPT vialation in the processes in which one of the invariances C, P, or T is violated. Such are the processes initiated by weak interaction, in particular, the decays of -leptons. Up to now there is no data on the mass di erence of ? and +. In this paper we measure the masses of ? and + separately and determine their mass di erence which is practically not sensitive to the systematic errors because they shift the mass value in the same way both for ? and for +. We analyse the 3-prong decays of -leptons using the method developed by ARGUS 3] for measurement the mass of -lepton. It consists of the construction of the variable which is smaller than or equal to mass of the and analysing its behaviour near the boundary of physically allowed region . We also apply the same idea for -neutrino mass measurement and construct the variable which is greater than or equal to the mass of invisible or unmeasured particles. The best upper limit for -neutrino mass was obtained by the ALEPH collaboration 4] from the analysis of the two-dimensional distribution mhad ? Ehad. The method which was used in this work has smaller dependance on the shape of theoretical distributions of the decay products of -lepton and di erent systematics. The data used were collected by the DELPHI experiment at LEP in the years 1991 to 1994 at centre-of-mass energies around 91.2 GeV.
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3,000
6%
2,500
2,000
4%
1,500
2% 0% -2% -4% -6%
0 2 4 6 8 10 12 14 16 18 20
1,000
500
0
Years
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Finance
School of Management and Economics
Example: Future Value of a Lump Sum
1 Year 2 Years $1.1 $1.21 Simple interest: 0.1 Simple interest: 0.1+0.1=0.2 Compound interest: 0.01
3 Years 4 Years
$1.331 $1.4641
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Finance
School of Management and Economics
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Finance
School of Management and Economics
Present Value of a Lump Sum
FV = PV *(1+ i)
n
Divide both sides by (1+i)n to obtain:
Present value factor
FV −n PV = = FV*(1+ i) n (1+ i)
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Finance
School of Management and Economics
Time Value of Money
The time value of money refers to the fact that money in hand today is worth more than the expectation of the same amount to be received in the future. – Interest – Purchasing power – Uncertainty
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Finance
School of Management and Economics
Financial Decisions
Costs and benefits being spread out over time.
– The values of sums of money at different dates. – The same amounts of money at different dates have different values.
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Finance
School of Management and Economics
Compounding
– Present value (PV) – Future value (FV) – Simple interest: the interest on the original principal – Compound interest: the interest on the interest – Future value factor
FV = $1× (1 + 0.06 / 12)12 = 1.06168
General formula
APR EFF = 1 + m
m
−1
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Finance
School of Management and Economics
Effective Annual Rates of an APR of 6%
4
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Finance
School of Management and Economics
Future Value of a Lump Sum
FV = PV * (1 + i )
FV with growths from -6% to +6%
3,500
n
Future value factor
Future Value of $1000
the discount rate
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Finance
School of Management and Economics
Example: Present Value of a Lump Sum
You have been offered $40,000 for your printing business, payable in 2 years. Given the risk, you require a return of 8%. What is the present value of the offer?
Value of $5 Invested
– More generally, with an investment of $5 at 10% we obtain
1 Year 2 years 3 years 4 Years $5*(1+0.10) $5.5*(1+0.10) $6.05*(1+0.10) $6.655*(1+0.10) $5.5 $6.05 $6.655 $7.3205
FV PV = (1 + i ) n 40,000 = (1 + 0.08) 2 = 34293.55281 ≅ $34,293.55 today
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ce
School of Management and Economics
Solving Lump Sum Cash Flow for Interest Rate
FV = PV * (1 + i ) n = $1500 * (1 + 0.03) 5 = $1738.91111145
n i PV FV Result 5 3% 1,500 ? 1738.91111145
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Finance
School of Management and Economics
Calculation by Excel
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Finance
School of Management and Economics
Value of Investing $1 at an Interest Rate of 10%
– Continuing in this manner you will find that the following amounts will be earned:
As the frequency of compounding increases, the effective annual rate increases.
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Finance
School of Management and Economics
Frequency of Compounding
Note that as the frequency of compounding increases, so does the annual effective rate. What occurs as the frequency of compounding rises to infinity (i.e. continuous compounding)?
Frequency of Compounding
– Annual percentage rate (APR) – Effective annual rate (EFF)
Suppose you invest $1 in a CD, earning interest at a stated APR of 6% per year compounded monthly.
If you invest $15,000 for ten years, you receive $30,000. What is your annual return?
Finance
School of Management and Economics
Chapter 3: Allocating Resources Over Time
Objective
Explain the concepts of compounding and discounting and to provide examples of real life Applications
Annual Percentage rate 6% 6% 6% 6% 6% 6% 6% Frequency of Compounding 1 2 4 12 52 365 ∞ Annual Effective Rate 6.00000% 6.09000% 6.13636% 6.16778% 6.17998% 6.18313% 6.18365%
FV = PV * (1 + i ) n FV ⇒ = (1 + i ) n PV ⇒ (1 + i ) = ⇒ i=
n
FV PV
n
FV −1 PV
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Finance
School of Management and Economics
Example: Interest Rate on a Lump Sum Investment
APR APR EFF = Lim1+ −1 =e m→∞ m
m
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Finance
School of Management and Economics
Present Value
– In order to reach a target amount of money at a future date, how much should we invest today? – Discounting – Discounted-cash-flow (DCF)