Hi XWiki users, I have encountered a problem where after running XWiki on my tomcat server for a week, i get an java.lang.OutOfMemoryError: PermGen space error. It appears that xwiki consumed all the java heap space. I believe the problem may be related to unreleased DB connections because, I noticed that everytime I try to shutdown tomcat, it hangs with xwiki deployed, also by running "ps aux" i see the postgresql connection processes belonging to xwiki still running. I tried deploying another application that uses hibernate + postgresql on the same tomcat running xwiki, and upon shutting down the server, all db connection processes from the other application gracefully terminate but not the ones from xwiki. My question is does anyone ever had this problem before? If so what is the solution? Solutions that I have tried but did NOT work: 1- Increase java heap with -Xmx512m 2- Reduce the maximum and minimum idle DB connections My system specs: OS: Linux ubuntu kernel 2.6.20 Java: 1.6.0_05-13 Xwiki: 1.4 (binary distribution) Posgresql: 8.2.6 Total RAM: 1Gb

Thanks for the prompt response. The answer regarding to large attachments is no. I don't have any large attachments in any of my pages. The "out-of-memory" error happens without any page in common, but when that happens, any other page that I want to access will result with the same error. It is like once memory has run out, it is unrecoverable. You may be right regarding to the DB connections threads not receiving the shutdown message, but that does not explain why i can't properly shutdown tomcat with XWiki deployed. Again, Tomcat shutdows smoothly when XWiki is not present. I don't mind not being able to gracefully shutdown tomcat, since i can always do "kill -9 <pid>", but what annoys me is the out-of-memory error after certain time. What could be the problem? This is happening on my development machine, but I am going to build another Linux machine right now and try if I can replicate the problem. Richard server for a week, i get an java.lang.OutOfMemoryError: PermGen space error. It appears that xwiki consumed all the java heap space. I believe the problem may be related to unreleased DB connections because, I noticed that everytime I try to shutdown tomcat, it hangs with xwiki deployed, also by running "ps aux" i see the postgresql connection processes belonging to xwiki still running. I tried deploying another application that uses hibernate + postgresql on the same tomcat running xwiki, and upon shutting down the server, all db connection processes from the other application gracefully terminate but not the ones from xwiki. the solution? _________________________________________________________________ E-mail for the greater good. Join the i'm Initiative from Microsoft. http://im.live.com/Messenger/IM/Join/Default.aspx?source=EML_WL_GreaterGood _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

Notice that PermGen space is not java heap. Therefore I suppose it is unlikely to have anything to do with attachment. Not in this case. You may want to check if other web applications are deployed to your tomcat instance - and if they use many classes/libs. Then you may want to increase the "-XX:MaxPermSize" or undeploy some webapps.

Pavel On Thu, May 29, 2008 at 9:16 PM, Richard V. &lt;xgcom(a)hotmail.com&gt; wrote: > Thanks for the prompt response. > > The answer regarding to large attachments is no. I don't have any large > attachments in any of my pages. > > The "out-of-memory" error happens without any page in common, but when that > happens, any other page that I want to access will result with the same > error. It is like once memory has run out, it is unrecoverable. > > You may be right regarding to the DB connections threads not receiving the > shutdown message, but that does not explain why i can't properly shutdown > tomcat with XWiki deployed. Again, Tomcat shutdows smoothly when XWiki is > not present. I don't mind not being able to gracefully shutdown tomcat, > since i can always do "kill -9 <pid>", but what annoys me is the > out-of-memory error after certain time. > > What could be the problem? This is happening on my development machine, but > I am going to build another Linux machine right now and try if I can > replicate the problem. > > Richard > >> Date: Thu, 29 May 2008 19:46:20 +0200 >> From: sergiu(a)xwiki.com >> To: users(a)xwiki.org >> Subject: Re: [xwiki-users] Xwiki memory leak? >> >> Richard V. wrote: >>> Hi XWiki users, >>> >>> I have encountered a problem where after running XWiki on my tomcat > server for a week, i get an java.lang.OutOfMemoryError: PermGen space error. > It appears that xwiki consumed all the java heap space. I believe the > problem may be related to unreleased DB connections because, I noticed that > everytime I try to shutdown tomcat, it hangs with xwiki deployed, also by > running "ps aux" i see the postgresql connection processes belonging to > xwiki still running. I tried deploying another application that uses > hibernate + postgresql on the same tomcat running xwiki, and upon shutting > down the server, all db connection processes from the other application > gracefully terminate but not the ones from xwiki. >>> My question is does anyone ever had this problem before? If so what is > the solution? >>> Solutions that I have tried but did NOT work: >>> 1- Increase java heap with -Xmx512m >>> 2- Reduce the maximum and minimum idle DB connections >>> >>> My system specs: >>> >>> OS: Linux ubuntu kernel 2.6.20 >>> Java: 1.6.0_05-13 >>> Xwiki: 1.4 (binary distribution) >>> Posgresql: 8.2.6 >>> Total RAM: 1Gb >>> >> AFAIK, there isn't a leak, but a somewhat "normal" behavior caused by >> the cache settings. The cache is configured to be a fixed size LRU >> cache, so if you store large entries in the cache, they will be kept >> there. The OOM error appears mostly when there are large attachments in >> the database. You should either reduce the size of the attachment cache >> or increase the memory. >> >> The shutdown problem is a different thing, it doesn't have anything to >> do with the database connections. I think it is because of some threads >> we're spawning that don't receive the shutdown message (the quartz >> scheduler for example). A memory leak regarding DB connections would >> mean there are thousands of open connections to the database, but I am >> pretty sure that's not the case, right? >> >> So, the main question is: Are there many & pretty large attachments in >> the wiki?