WebSphere Application Server Network Deployment, Version 6.0.x     Operating Systems: AIX, HP-UX, Linux, Solaris, Windows

Monitoring overall system health

Why and when to perform this task

Monitoring overall system health is of fundamental importance to understand the health of every system involved that includes Web servers, application servers, databases, back-end systems, and any other systems critical to running your Web site. If any system has a problem, it might have a rippling effect and cause the servlet is slow problem. IBM and several other business partners leverage the WebSphere APIs to capture this kind of performance data and to incorporate this data into an overall 24-by-7 monitoring solution across multiple products. WebSphere Application Server provides Performance Monitoring Infrastructure (PMI) data to help monitor the overall health of the WebSphere Application Server environment. PMI provides average statistics on WebSphere Application Server resources, application resources, and system metrics. Many statistics are available in WebSphere Application Server, and you might want to understand the ones that most directly measure your site to detect problems.
To monitor overall system health, monitor the following statistics at a minimum:
Metric Meaning
Average response time Include statistics, for example, servlet or enterprise beans response time. Response time statistics indicate how much time is spent in various parts of WebSphere Application Server and might quickly indicate where the problem is (for example, the servlet or the enterprise beans).
Number of requests (transactions) Enables you to look at how much traffic is processed by WebSphere Application Server, helping you to determine the capacity that you have to manage. As the number of transactions increase, the response time of your system might be increasing, showing the need for more system resources or the need to retune your system to handle increased traffic.
Number of live HTTP sessions The number of live HTTP sessions reflects the concurrent usage of your site. The more concurrent live sessions, the more memory is required. As the number of live sessions increase, you might adjust the session time-out values or the Java virtual machine (JVM) heap available.
Web server thread pools Interpret the Web server thread pools, the Web container thread pools, and the Object Request Broker (ORB) thread pools, and the data source or connection pool size together. These thread pools might constrain performance due to their size. The thread pools setting can be too small or too large, therefore causing performance problems. Setting the thread pools too large impacts the amount of memory that is needed on a system or might cause too much work to flow downstream if downstream resources cannot handle a high influx of work. Setting thread pools too small might also cause bottlenecks if the downstream resource can handle an increase in workload.
The Web and Enterprise JavaBeans (EJB) thread pools
Database and connection pool size
JVM Memory Use the JVM memory metric to understand the JVM heap dynamics, including the frequency of garbage collection. This data can assist in setting the optimal heap size. In addition, use the metric to identify potential memory leaks.
CPU You must observe these system resources to ensure that you have enough system resources, for example, CPU, I/O, and paging, to handle the workload capacity.
I/O
System paging
To monitor several of these statistics, WebSphere Application Server provides the performance monitoring infrastructure to obtain the data, and provides the Tivoli Performance Viewer in the administrative console to view this data.



Sub-topics
Why use Tivoli Performance Viewer?
Performance Monitoring Infrastructure (PMI)
Enabling PMI data collection
Developing your own monitoring applications
Extending PMI using Custom PMI API
Monitoring performance with Tivoli Performance Viewer (TPV)
Third-party performance monitoring and management solutions
Task topic    

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Last updated: Mar 17, 2005 4:28:29 AM CST
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