Analysis of the Internet Communication Manager (ICM)

最新推荐文章于 2019-05-16 11:45:04 发布

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本文介绍了SAP Internet Communication Manager (ICM)的基本概念及其在SAP Java实例或ABAP服务器中的作用。ICM作为连接浏览器与SAP工作进程的重要组件，通过监控工具可以检查其负载情况，包括线程状态、内存管道负载及缓存机制效率等关键指标。

The Internet Communication Manager (ICM) provides communication between the web browser and SAP work processes of the SAP Java instance or ABAP server. It does not process business logic or generate web pages, which means the load it has to manage is rather low in comparison to the work processes. With respect to the operating system, the ICM is a process icman.exe. Internally, the ICM is scalable, which means it has several threads.

To monitor the ICM load, call the ICM monitor (Transactions SMICM):

TOOLS • ADMINISTRATION • MONITOR • SYSTEM MONITORING • ICM MONITOR.

In the initial monitor screen , you can see the status of individual ICM threads. The upper part of the screen shows statistical information on the status of the threads (in the THREADS GENERATED row), the connections (CONNECTIONS USED row), and the queue (USED QUEUE ENTRIES row). You can recognize a bottleneck in the ICM if the PEAK value is the same as the Maximum value for at least one of these three parameters.

Memory pipes

To monitor the load on memory pipes, select GoTo • MEMORY PIPES • DISPLAY DATA in the ICM monitor. Among other things, you will find information here on the number of memory pipe buffers (TOTAL #MPI BUFFER field) and their loads (PEAK BUFFER USAGE field). If the value for PEAK is the same as the value for Maximum, there is a bottleneck.

Cache mechanisms

The ICM has a cache in which it records web pages or parts of web pages, such as image files. You can find an overview of the data in the ICM monitor cache under Go To • HTTP SERVER CACHE • DISPLAY. You can get statistical data on the fill level and efficiency of the cache by selecting GoTo • HTTP SERVER CACHE • DISPLAY STATISTICS. Interesting values here include the absolute size of the cache (CACHE SIZE [BYTES) field) and the occupied space in the OCCUPIED CACHE MEMORY (BYTES) field.

The ICM is activated via the SAP profile parameter rdisp/start_icman = true. (By default, the ICM is active after installation of the SAP NetWeaver Application Server.) In the online appendix Performance-Relevant Configuration Parameters and Key Figures, you will find an overview of the SAP profile parameters relevant to performance and used in the configuration of the ICM, memory pipes, and cache.