Hi folks,
I am puzzled by the situation that Tomcat 4.1.31 meets sudden spikes of used
memory sometimes. Then it will increase to throw OutOfMemory Exception and
tomcat is hanging.

Those memory spikes appear in my Web application for a long time. The odd
thing is that it does not seem to progressively go up but rather spike up
with each next full GC will clean less objects out.

This is three pictures of the gc log.
http://my.sme.cn/jsp/main/memoryleak.png
http://my.sme.cn/jsp/main/memoryleak2.png
http://my.sme.cn/jsp/main/memoryleak3.png
I used HPjtune tool to watch the gc log.
System using windows 2000 server, 2*CPU, 2G memory, JSDK 1.4.2_05, tomcat
4.1.31, And
set -Xms1250m -Xmx1250m -server -XX:+UseParallelGC -Xloggc:D:\tomcat\logs\gc.log

At first, I doubt if my app program has memory leak. But the application
only runs by JSPs and javabeans.(I abandon using DBCP pool and any thread
operation because of the memory leak.) I think simple JSPs can't cause the
memory spike. I have a monitor.jsp to show my application status.
http://my.sme.cn/jsp/main/monitor.jsp

The WebSite uses normally below 100M memory heap through my monitor.jsp. It
can run a few days, or a few hours before the spike appears. It is
irregular. I read the access_log and want to find answer. But I can't find
any clue.

Then, I think tomcat 4.1.* has some bugs causing the memory leak. I upgraded
my application to tomcat 5.0.18, but I met same thing.

The WebSite's hits is more than 200,000 per day. I try to use OptimizeIt 6
profile to watch memory status, but OptimizeIt always exits after runs 2~3
hours. I guess this program maybe need using progressive memory of system to
log things and analyze those when I notice Optimizeit used 1.6G system
memory.(and OptimizeIt 6 profile only runs under tomcat 4.1.*! So I return
to tomcat 4.1.31)

I don't know how to cause the thing and how to find solution. Any suggestion
is appreciated. Thanks.

Li Zhenxing

---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to