Viewing performance data from request metrics

The trace records for request metrics data are output to two log files: the Web server plug-in log file and the application server log file. The default directory for these log files is plugin_install_root/logs/web_servername/http_plugin.log and install_root/profiles/profile/logs/servername) and the default names are SystemOut.log and http_plugin.log. You might, however, specify these log file names and their locations.

In the WAS log file the trace record format is 

PMRM0003I: parent:ver=n,ip=n.n.n.n,time=nnnnnnnnnn,pid=nnnn,reqid=nnnnnn,event=nnnn 
- 
current:ver=n,ip=n.n.n.n,time=nnnnnnnnnn,pid=nnnn,reqid=nnnnnn,event=nnnn 
           type=TTT detail=some_detail_information elapsed=nnnn

In the Web server plug-in log file the trace record format is 

PLUGIN:
parent:ver=n,ip=n.n.n.n,time=nnnnnnnnnn,pid=nnnn,reqid=nnnnnn,event=nnnn 
- current:ver=n,ip=n.n.n.n,time=nnnnnnnnnn,pid=nnnn,reqid=nnnnnn,event=nnnn 
           type=TTT detail=some_detail_information elapsed=nnnn bytesIn=nnnn 
           bytesOut=nnnn

The trace record format is composed of two correlators: a parent correlator and current correlator. The parent correlator represents the upstream request and the current correlator represents the current operation. If the parent and current correlators are the same, then the record represents an operation that occurs as it enters WebSphere Application Server.

To correlate trace records for a particular request, collect records with a message ID of PMRM0003I from the appropriate application server log files and the PLUGIN trace record from the Web server plug-in log file. Records are correlated by matching current correlators to parent correlators. We can create the logical tree by connecting the current correlators of parent trace records to the parent correlators of child records. This tree shows the progression of the request across the server cluster. Refer to Why use request metrics? for an example of the transaction flow.

The parent correlator is denoted by the comma separating fields following the keyword, parent:. Likewise, the current correlator is denoted by the comma separating fields following, current:.

The fields of both parent and current correlators are:

  • ver: The version of the correlator. For convenience, it is duplicated in both the parent and current correlators.

  • ip: The IP address of the node of the application server that generated the correlator. If the system has multiple IP addresses, request metrics uses one of the IP addresses to identify the system.

  • pid: The process ID of the application server that generated the correlator.

  • time: The start time of the application server process that generated the correlator.

  • reqid: An ID that is assigned to the request by request metrics, unique to the application server process.

  • event: An event ID that is assigned to differentiate the actual trace events.

Following the parent and current correlators, the metrics data for timed operation are:

  • type: A code that is represents the type of operation being timed. Supported types include HTTP, URI, EJB, JDBC, JMS, COMMONJ_WORK_POOLED, COMMONJ_TIMER, Web services requester, and Web services provider.

  • detail: Identifies the name of the operation being timed (See the following description of Universal Resource Identifier (URI), HTTP, EJB, JDBC, JMS, asynchronous beans, and Web services.)

  • elapsed: The measured elapsed time in <units> for this operation, which includes all sub-operations called by this operation. The unit of elapsed time is milliseconds.

  • bytesIn: The number of bytes from the request that is received by the Web server plug-in.

  • bytesOut: The number of bytes from the reply that is sent from the Web server plug-in to the client.

The type and detail fields that are described include:

  • HTTP: The Web server plug-in generates the trace record. The detail is the name of the URI that is used to invoke the request.

  • URI: The trace record is generated by a Web component. The URI is the name of the URI that is used to invoke the request.

  • EJB: The fully qualified package and the method name of the enterprise bean.

  • JDBC: The values select, update, insert or delete for prepared statements. For non-prepared statements, the full statement can display.

  • JMS: JMS includes the particulars of various JMS parameters

  • Asynchronous beans:The detail specifies the name of the asynchronous beans. Asynchronous beans include two types: COMMONJ_WORK_POOLED and COMMONJ_TIMER.

  • Web services:Web services include the particulars of various Web services parameters. Web services include two types: Web services requestor and Web services provider.

 

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