Trouble shooting in Websphere

Generally in trouble shooting mainly we concentrate on
1)Log files
2)Hung threads
3)OOM(OutOfMemory)
4)CPU starvation
5)Disk space issues
6)Web container issues


Log Files


 Application Server---->jvm logs----------->SystemOut.log(Start,Stop,Application processes)
                                                      ----------->SystemErr.log(server related errors)
                             
                                ----->ProcessLogs------>NativeStdOut.log(Sun jdk related memory,GC,etc.,)
                                                             ------>NativeStdErr.log(IBM jdk relatede memory GC,etc..,)

Node Agent   ---->jvm logs----------->SystemOut.log(Start,Stop,Application processes)
                                                      ----------->SystemErr.log(server related errors)
                             
                                ----->ProcessLogs------>NativeStdOut.log(Sun jdk related memory,GC,etc.,)
                                                             ------>NativeStdErr.log(IBM jdk relatede memory GC,etc..,)

DMGR   ---->jvm logs----------->SystemOut.log(Start,Stop,Application processes)
                                                      ----------->SystemErr.log(server related errors)
                             
                                ----->ProcessLogs------>NativeStdOut.log(Sun jdk related memory,GC,etc.,)
                                                             ------>NativeStdErr.log(IBM jdk relatede memory GC,etc..,)

IHS------------>access.log(User details,IP,Time stamp,Page details,Time taken to access page)
       ------------>error.log(SSL information,Start and Stop of webserver)

Plugin---------->http_plugin.log (Server down issues, Information regarding connection b/w                                                                                     Application server)


In addition to this we have

FFDC----First Failure Data Capture 
Service.log or Activity.log----------->IBM service logs (Binary format )

************ShowLog command to see file ***********

Out Of Memory (OOM):



 Out of memory exception arises due to following reasons

1)Insufficient heap memory
2)Memory leaks in application code
           (Memory leaks in application occurs mainly because , the object remain in the heap memory even after the process is completed . This can be removed by using garbage collection)
3)JVM heap memory is available but it is contiguous.
    (the heap memory is allocated for each request.Each request occupies some block in the heap memory , and one request needs 60mb space to fulfil the request, 120 mb space is available but not in a single block. this condition is contiguous. in rare conditions this situation occurs . From java 6 onwards this problem is rectified)
4) Insufficient native memory.


OOM can be analysed by taking thread dump and heap dump and GC LOG

Thread dump:- snapshot of live running java threads in the application server 

 Heap dump  :- snapshot of live running java objects in the heap memory

Web container issues

200---success
302---re-directional issue
403---forbidden error
404--Page not found issue
           (This occur due to i>static content not available 
                                         ii>Application is not in running(Not application server,deployed application
                                         iii>Page not available in the EAR file provide by developer
                                         iv>in-accurate data in the plugin-cfg.xml page
                                         v>Virtual host wrong mapping .
500---internal server issue
             (Check http_plugin.log file to find the reason)



To be continued............





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