Re: [Exist-open] How to limit the Memory Consumption of eXist? Problem with scope=session in server-config.wsdd?

[Andreas H. <and...@fi...>]

Dear Wolfgang,

thanks for the fast reply!

Wolfgang wrote:
>> So here my question: Is it possible to limit the memory consumption 
>> of eXist by a specific configuration? Or is there some memory leak 
>> which could maybe be fixed? How can I contribute to find this memory 
>> leak (if there is any?)
>
> Your memory and cacheSize configuration looks ok. I thus assume 
> there's a memory leak. You say you are using SOAP. Another user, 
> Gregory, recently uploaded a patch which says that axis 1.3 has a 
> known memory leak:
>
> http://sourceforge.net/tracker/index.php?func=detail&aid=2531223&group_id=17691&atid=317691 
>
>
> I would thus suggest to update to the current eXist-stable-1.2 branch 
> and replace the axis jars as described. I'll try to do this as well.

OK, I'll  try this.

>
>> I have the suspicion that the regular update each 10 Seconds of few 
>> documents prevents the database to clean up the memory...  Maybe it 
>> is also a tomcat/axis problem. I noticed, that you are using 
>> "scope=session" instead of "scope=application" in the 
>> server-config.wsdd. Is it safe to switch the scope to "application"? 
>> This often solves tomcat memory issues...
>
> I have no experience with those settings, sorry.
scope=session means, that your Query and Admin classes are instantiated 
for each HTTP session. If you set scope=application then the Query and 
Admin classes are instantiated only once when the first SOAP request 
arrives and subsequent calls of the SOAP methods are invoked on the same 
Object (Instance). It is told that scope=session often leads to memory 
problems within tomcat...

So it depends on the structure of the Query and Admin classes if it is 
possible to switch to scope=application. It is mainly a matter of being 
thread safe or not. I will just try it a give you a feedback within the 
next weeks...

Thanks, Andreas

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Andreas Hoheisel
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