Performance Monitoring Infrastructure Request Metrics data output

The trace records for Performance Monitoring Infrastructure (PMI) Request Metrics data are output to two log files: the Web server plug-in log file and the appserver log file. The default directory for these log files is <$WAS_ROOT/logs> (or the name given to your server <$WAS-ROOT/logs/server>) and default names are SystemOut.log and http_plugin.log. Users might, however, specify these log file names and their locations.

In the WebSphere Application Server 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 occurred as it entered WebSphere Application Server.

To correlate trace records for a particular request, collect records with a message ID of PMRM0003I from the appropriate appserver 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. The logical tree can be created 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 Measuring data requests (Performance Monitoring Infrastructure 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 as follows:

• 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 appserver that generated the correlator.

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

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

• reqid: An ID assigned to the request by Request Metrics, unique to the appserver process.

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

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

• type: A code representing the type of operation being timed. Supported types include , URI, EJB and JDBC.

• detail: Identifies the name of the operation being timed (See the description of Universal Resource Identifier (URI), , Enterprise bean and Java Database Connectivity (JDBC) below.)

• 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 received by the Web server plug-in.

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

The type and detail fields are described as follows:

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

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

• EJB: The fully qualified package and 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 appear.

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Measuring data requests (Performance Monitoring Infrastructure Request Metrics)
    

 

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