WAS v8.5 > MonitoringMonitoring application flow
Monitoring, optimizing, and troubleshooting WebSphere Application Server performance can be a challenge. This article gives you a basic strategy for monitoring with an understanding of the application view.
This information includes understanding the application flow that satisfies the end user request. This perspective provides the views of specific servlets that access specific session beans, entity container-managed persistence beans, and a specific database. This perspective is important for the in-depth internal understanding of who is using specific resources. Typically at this stage, you deploy some type of trace through the application, or thread analysis under load condition techniques to isolate areas of the application and particular interactions with the back-end systems that are especially slow under load. In this case, WAS provides request metrics to help trace each individual transaction as it flows through the application server, recording the response time at different stages of the transaction flow (for example, request metrics records the response times for the web server, the web container, the Enterprise JavaBeans container, and the back-end database). In addition, several IBM development and monitoring tools that are based on the request metrics technology (for example, Tivoli Monitoring for Transaction Performance) are available to help view the transaction flow.
Subtopics
- Why use request metrics?
Request metrics is a tool that enables you to track individual transactions, recording the processing time in each of the major WAS components.- Data we can collect with request metrics
Typically, different components of the enterprise application might be hosted across several nodes in a distributed system. For example, the servlets might be hosted on one node, while the enterprise beans on which these servlets depend might be hosted on an entirely different node. When a request comes to a process, the process might send the request to one or more downstream processes, as shown in the following figure:- Get performance data from request metrics
This topic describes how to enable request metrics.- Request metric extension
Certain applications might require additional instrumentation points within the request metrics flow. For example, you might want to understand the response time to a unique back-end system as seen in the following call graph:- Differences between Performance Monitoring Infrastructure and request metrics
PMI provides information about average system resource usage statistics, with no correlation between the data across different WAS components. For example, PMI provides information about average thread pool usage. Request metrics provides data about each individual transaction, correlating this information across the various WAS components to provide an end-to-end picture of the transaction, as shown in the following diagram:- Why use request metrics?
Request metrics is a tool that enables you to track individual transactions, recording the processing time in each of the major WAS components.- Get performance data from request metrics
This topic describes how to enable request metrics.- Request metric extension
Certain applications might require additional instrumentation points within the request metrics flow. For example, you might want to understand the response time to a unique back-end system as seen in the following call graph:
Subtopics
- Why use request metrics?
Request metrics is a tool that enables you to track individual transactions, recording the processing time in each of the major WAS components.- Data we can collect with request metrics
Typically, different components of the enterprise application might be hosted across several nodes in a distributed system. For example, the servlets might be hosted on one node, while the enterprise beans on which these servlets depend might be hosted on an entirely different node. When a request comes to a process, the process might send the request to one or more downstream processes, as shown in the following figure:- Get performance data from request metrics
This topic describes how to enable request metrics.- Request metric extension
Certain applications might require additional instrumentation points within the request metrics flow. For example, you might want to understand the response time to a unique back-end system as seen in the following call graph:- Differences between Performance Monitoring Infrastructure and request metrics
PMI provides information about average system resource usage statistics, with no correlation between the data across different WAS components. For example, PMI provides information about average thread pool usage. Request metrics provides data about each individual transaction, correlating this information across the various WAS components to provide an end-to-end picture of the transaction, as shown in the following diagram:- Why use request metrics?
Request metrics is a tool that enables you to track individual transactions, recording the processing time in each of the major WAS components.- Get performance data from request metrics
This topic describes how to enable request metrics.- Request metric extension
Certain applications might require additional instrumentation points within the request metrics flow. For example, you might want to understand the response time to a unique back-end system as seen in the following call graph:
Related
Monitoring overall system health
Monitoring end user response time