Pavel wrote:
> 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.

You are right, PermGen has nothing to do with objects used by the XWiki 
platform. So, either the default size is not enough to hold many 
applications, or there is a bug in one of the libraries we're using that 
creates classes (Groovy? Hibernate+CGLib?). For the moment try 
increasing the -XX:MaxPermSize to 128M and see if the problem persists.

> Pavel
> 
> On Thu, May 29, 2008 at 9:16 PM, Richard V. <[EMAIL PROTECTED]> 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: [EMAIL PROTECTED]
>>> To: [email protected]
>>> 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?

-- 
Sergiu Dumitriu
http://purl.org/net/sergiu/
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