The fact that you have the same symptons in tomcat 4 and in 5 points towards your application as being the culprit.
Is there any reason why you chose tomcat 5.0.18 instead of one of the many newer releases? I would find another profiler that works with both and try your tests again. Ta Matt -----Original Message----- From: Li Zhenxing [mailto:[EMAIL PROTECTED] Sent: 08 December 2004 13:47 To: [EMAIL PROTECTED] Subject: OutOfMemory! Tomcat meets sudden spikes of used memory sometimes. 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]
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