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From Michael.Bom...@WellsFargo.COM
Subject RE: HTTP Connection Pool grows continuously
Date Fri, 25 Oct 2002 14:21:17 GMT
If I set a maxProcessors value, Tomcat gives me new connection threads until
it reaches the limit, and then connection requests fail. 

The high timeout value is an end user requirement for the app. In any case,
I know that Tomcat is allocating many more threads - upwards of a thousand -
than I ever have concurrently connected users.  It is almost as if threads
are not being reused. I know that in earlier releases of Tomcat, it was
necessary to explicitly configure pooling in server.xml, but after 4.0 it is
the default (and only) option. 

What would be very useful is an explanation of exactly how the Tomcat
connection pooling logic is supposed to work in release 4.0. 
> -----Original Message-----
> From:	Kwok Peng Tuck [SMTP:pengtuck@makmal.com]
> Sent:	Friday, October 25, 2002 1:46 AM
> To:	Tomcat Users List
> Subject:	Re: HTTP Connection Pool grows continuously
> 
> If you change this value:  
> 
> maxProcessors="-1" 
> 
> to some value like 20 what happens?
> 
> Kristian A. Leth wrote:
> 
> >You got a pretty high connection timeout on (1200000) 20min.
> >Try setting it to something like 15000 or even lower.
> >
> >You could also fix your min and max heapsize to get more continously
> >garbagecollection
> >
> >It could also be due to problems in your code, delaying, stopping or
> >killing threads.
> >
> >Regards
> >
> >Kleth
> >
> >-------------------------------------------------------------------------
> -----------------
> >
> >Kristian A. Leth.
> >Systemsdeveloper, Maersk Data A/S.
> >--------------------------------------------------------------
> >Professionals are predictable;
> >the world is full of dangerous amateurs.
> >-------------------------------------------------------------------------
> -----------------
> >
> >
> >
> >
> >|---------+----------------------------->
> >|         |                             |
> >|         |             Michael.Bombyk@W|
> >|         |             ellsFargo.COM   |
> >|         |                             |
> >|         |             24-10-2002 22:44|
> >|         |             Please respond  |
> >|         |             to "Tomcat Users|
> >|         |             List"           |
> >|         |                             |
> >|         |                             |
> >|---------+----------------------------->
> >
> >-------------------------------------------------------------------------
> -----------------------------------------------------|
> >  |
> |
> >  |       To: tomcat-user@jakarta.apache.org
> |
> >  |       cc:
> |
> >  |       Subject:  HTTP Connection Pool grows continuously
> |
> >
> >-------------------------------------------------------------------------
> -----------------------------------------------------|
> >
> >
> >
> >I am running Tomcat 4.0.3 standalone on WIndows 2000 Server. I have a
> >maximum of perhaps 50 concurrent connections at any given time. I have
> the
> >following server.xml configuration for the HTTPConnector:
> >
> ><Connector className="org.apache.catalina.connector.http.HttpConnector"
> >port="80" minProcessors="5" maxProcessors="-1" enableLookups="true"
> >redirectPort="8443" acceptCount="10" debug="0"
> connectionTimeout="1200000"
> >/>
> >My problem is this:
> >My connection thread pool grows continuously until the point that all JVM
> >memory allocated to Tomcat is exhausted. This can be observed in the
> >catalina log with messages like these:
> >2002-10-24 12:02:14 HttpProcessor[80][1077] Starting background thread
> >2002-10-24 12:02:14 HttpProcessor[80][1078] Starting background thread
> >I understand that maxProcessors="-1" allows Tomcat to create as many
> >threads
> >as it needs to satisfy http requests, but doesn't connection thread
> pooling
> >allow reuse? I would expect that the pool would not grow any larger than
> >the
> >highest number of concurrent connections. Previously when I used
> >maxProcessors to set a connection limit, I found that I rapidly reached
> >this
> >limit, which is why I set the max value to infinity. But this is not how
> I
> >would expect connection thread pooling - which is supposed to be the
> >default
> >option in 4.0 - to work. What am I missing?
> >Thanks for your help.
> >
> >
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> >
> >
> >
> >
> >
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> >  
> >
> 
> 
> 
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