activity.log

The application server creates the activity.log file from the activity of the various WebSphere Application Server components. you cannot read this log with a text reader. You ca use this script called, showlog under appserver root.
Ex.,
./WAS_INST_ROOT/bin/showlog PATH_TOACTIVITY_LOG/activity.log
like this
websphe: /software/opt/IBM/WebSphere/AppServer/bin
$ ./showlog ../profiles/AppSrv*/logs/activity.log
This displays ur activity log something like this, just as a sample:
ExtendedMessage:
---------------------------------------------------------------
ComponentId: Application Server
ProcessId: 18124
ThreadId: 0000005d
ThreadName: WebContainer : 4
SourceId: com.ibm.ws.webcontainer.srt.SRTServletResponse
ClassName:
MethodName:
Manufacturer: IBM
Product: WebSphere
Version: Platform 6.0 [BASE 6.0.2.0 o0526.07]
ServerName: Node01Cell\Node01\server1
TimeStamp: 2008-12-22 12:27:17.175000000
UnitOfWork:
Severity: 2
Category: WARNING
PrimaryMessage: WARNING: Cannot set status. Response already committed