I have an application web based. using Oracle backend and Java front end.

App server is in weblogic and Solaris os and two cpu with 8 applications.

DB server is oracle 8.1.7 on Solaris

This application is getting slow when number of threads are more ( like many users login and related activities) . I found out that during the peak time the garbage collector is also not running properly.

I want to know how can we change the GC algorithm ( like concurrent GC / parallel GC etc )

Where do we give the settings of JVM ?

How to enable the parallel GC ?
How to set the heap size ?

Sounds like you're not properly releasing database connections and your application is getting starved of them.

ALWAYS make sure you release any connection to your database in the same method you make it.
And you should best also use a connection pool for increased performance, usually appservers these days provide you with one.

hi friends,

any new suggestion? please

hi friends,

any new suggestion? please

Hi Guy,

For the JVM Tuning a simple google search produced the following nice result...


Also, both ServerCrash and jwenting offered you nice possible solutions. What you're dealing with is very difficult to diagnose, work on without a lot of information. jwenting pointed out the most likely issue and ServerCrash pointed you to a document that explains how to change the algorithm for GC. You're going to have to take these resources yourself and figure out your own solution. Hopefully it is an easy issue of not closing your jdbc sessions. If it isn't, you're going to have to do a lot of your own detective work on your system. We most likely will not be able to help you.

Best of Luck,



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