JVM in Oracle Apps 11i

Analyzing Oracle Apps 11i JVM logs

In order to analyze Oracle apps 11i JVM, lets open stdout file for one of Group, I have selected OACoreGroup here, you know log file location (If not check previous page) , open file like OACoreGroup.X.stdout you should see output like below if GC(Grabage Collector) is set in Verbose mode.
48561.624: [GC 325980K->170382K(519168K), 0.2751056 secs]
49307.880: [GC 334862K->179171K(519168K), 0.2660486 secs]
50236.662: [GC 343651K->187797K(519168K), 0.2518720 secs]
50515.494: [Full GC[Unloading class sun. reflect. Generated Method Accessor 143]
[Unloading class sun. reflect. GeneratedMethodAccessor136]
[Unloading class sun. reflect. GeneratedMethodAccessor74]

Here first entry is time since JVM was started so each time you bounce Apache it will be reset to 0. So difference between two entries is seconds after which GC (Garbage Collector) was executed. First entry in bracket [ is Heap Size at start of GC & Second entry is Heap Size after GC was executed. Number mentioned in round bracket () is heap size currently attocated in K. If you see GC running very frequently , you can start thinking of increasing JVM heap size
First three entries were for Minor Garbage Collector & fourth one is FULL GC is for Full Garbage Collector.

connect using apps, sys or system & issue
select count(*), module from v$session where program like '%JDBC%' group by module;

Often you would like to know what is version of jdbc thin drivers that your Web Server ( Apache, ias 1.0.2.2.2 ) is using . To find out how you can check jdbc thin driver version Click Here

There are some tools available like jvmstst, jconsole .. but I never tried so wait till I configure one for my system. For monitoring via jconsole I read wonderful note on my favorite blogger's (Steven Chan) site. You can check same by Clicking Here