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Posted to users@tomcat.apache.org by LeeAnn Pultz <le...@extraview.com> on 2005/04/20 00:19:33 UTC
OutOfMemoryError - 100 thread limit?
I have a tomcat server with multiple copies of our web application
running. We are running into what seems to be a hard-coded limit on the
number of threads available to the Tomcat application.
I have added code to our servlet class which prints out the number of
active threads whenever I initialize the servlet. On Red Hat Linux boxes,
whenever we start up enough copies of the servlet to hit 100 active
threads, we reach an OutOfMemoryError - regardless of the Xms/Xmx settings
(memory profiling shows that we have plenty of memory available). On
Windows XP, 50 seems to be the magic number.
I have tried tweaking Xss parameters, my ulimit command in Linux shows
"unlimited" - and I have reached the same results with Tomcat 3.3.1, 4.0.28
and 5.0.28 using Java 1.4.1 and 1.4.2. When I use WebLogic 8.1 on the same
Linux box, I reach 241 active threads with no problems whatsoever (stopped
my testing at that number) so it does not seem to be an o/s limitation, or
a java limitation - which leads me to believe there is something in Tomcat?
Is the number of threads available to tomcat hard coded somewhere? Is there
a parameter or configuration setting that I can change to increase this?
If this question is better off posted to the developers list, please
someone, let me know :)
thanks!
LeeAnn Pultz
ExtraView Corporation
leeann@extraview.com
831-461-7100 x115
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Re: OutOfMemoryError - 100 thread limit?
Posted by LeeAnn Pultz <le...@extraview.com>.
No, unfortunately, changing those options doesn't seem to make any
difference either.
On tomcat 3, I even tried manipulating the thread pool settings (since in 4
and 5 those are handled inside tomcat).
But I'm seeing the same problems on 3, 4 and 5.0
> > In fact, I can cause the error to happen every single time, simply by
> > hitting the first web page (login page) of the application - I don't have
> > to log in, or do any "work". All I have to do to get the error to happen
> > is hit 18-19 different instances of the web application, watch the Active
> > thread count go up to 100 and tip over the tomcat.
>
>This isn't related to the minProcessors, maxProcessors & acceptCount
>settings for your connector in your server.xml by any chance?
>
>Regards,
>--
>Jason Bainbridge
>http://kde.org - webmaster@kde.org
>Personal Site - http://jasonbainbridge.com
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
>For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
LeeAnn Pultz
ExtraView Corporation
leeann@extraview.com
831-461-7100 x115
---------------------------------------------------------------------
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Re: OutOfMemoryError - 100 thread limit?
Posted by Jason Bainbridge <jb...@gmail.com>.
On 4/20/05, LeeAnn Pultz <le...@extraview.com> wrote:
> This is not a memory leak in the application - we have hooked up a profiler
> to the application and watched the actual memory usage when causing this
> issue to happen. We have lots of memory available, are nowhere near the
> Xmx limit, and the machine has lots of memory available over and above the
> Xmx limit.
>
> In fact, I can cause the error to happen every single time, simply by
> hitting the first web page (login page) of the application - I don't have
> to log in, or do any "work". All I have to do to get the error to happen
> is hit 18-19 different instances of the web application, watch the Active
> thread count go up to 100 and tip over the tomcat.
This isn't related to the minProcessors, maxProcessors & acceptCount
settings for your connector in your server.xml by any chance?
Regards,
--
Jason Bainbridge
http://kde.org - webmaster@kde.org
Personal Site - http://jasonbainbridge.com
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Re: OutOfMemoryError - 100 thread limit?
Posted by LeeAnn Pultz <le...@extraview.com>.
We did run some code that just makes threads, on the machine and it had no
effect - I'll incorporate that code inside a servlet, so we can do this
test against tomcat and see if it makes a difference.
We just tried the same test against tomcat 5.0 using port 8080 and not
using any of the mod_jk connectors, to see if that made a difference - we
found that we started with more active threads by uncommenting that section
of server.xml (started with 67 active threads rather than 44) and got a bit
higher (died at 118 threads rather than 100 threads) so I'm taking that
result to show that the actual number of threads allocated to the
application remained about the same, with or without the usage of mod_jk.
At 09:08 AM 4/20/2005, you wrote:
>that is some really odd behavior coming from Tomcat. I've probably run
>over 1K benchmarks on Tomcat over the last 3 years and I've yet to see
>that kind of behavior. Here are some random ideas to try, which I've
>used in the past. They may not help, but I figure it wouldn't hurt to
>suggest them.
>
>use jmeter to send 250 requests with 25 threads against the index page.
>
>then view the status in tomcat 5.5.4. Over time, you should see the
>number of threads drop to the minimum. Under normal conditions, tomcat
>will create enough threads to service those threads. after a few
>minutes, the thread count should drop. If it doesn't, it means
>something is keeping the connection open. if you see that, it is most
>likley an application bug. Another idea is to do netstat and see what
>the status of the connections are. It might be some of the
>connections are not closing.
>
>peter
>
>
>
>On 4/20/05, LeeAnn Pultz <le...@extraview.com> wrote:
> > We have no jsps in the application. The index.html page loads our servlet
> > class, and I've put logging of active number of threads at the beginning of
> > the servlet ini() and the very end of the service() methods in that servlet
> > class. The application initializes, but we aren't doing any of the real
> > "work" of rendering dynamic pages or talking to the database at this point.
> >
> > I get the same results whether my Xmx is 84 megs or 512 megs - we're just
> > not using that much memory.
> >
> >
> > At 08:48 AM 4/20/2005, Peter Lin wrote:
> > >that sounds very odd. so if I understand correctly. this happens when
> > >you hit the login page. I assume this don't happen with a static html
> > >page? by any chance are you using jsp tags or some web framework?
> > >
> > >peter
> > >
> > >
> > >On 4/20/05, LeeAnn Pultz <le...@extraview.com> wrote:
> > > > This is not a memory leak in the application - we have hooked up a
> profiler
> > > > to the application and watched the actual memory usage when causing
> this
> > > > issue to happen. We have lots of memory available, are nowhere
> near the
> > > > Xmx limit, and the machine has lots of memory available over and
> above the
> > > > Xmx limit.
> > > >
> > > > In fact, I can cause the error to happen every single time, simply by
> > > > hitting the first web page (login page) of the application - I
> don't have
> > > > to log in, or do any "work". All I have to do to get the error to
> happen
> > > > is hit 18-19 different instances of the web application, watch the
> Active
> > > > thread count go up to 100 and tip over the tomcat.
> > > >
> > > > We've gone through all of the suggested infomation out on the web -
> we've
> > > > tweaked the Xms, Xmx and Xss parameters - none of these changes
> made any
> > > > difference, since we're not actually running out of memory. I've
> > > > reproduced this on 3 different machines, all running Red Hat Linux
> ES 3.0 -
> > > > both with LD_ASSUME_KERNEL 2.4.19 and without, so the Linux
> threading model
> > > > doesn't seem to affect the problem.
> > > >
> > > >
> > > > At 04:16 AM 4/20/2005, you wrote:
> > > > >I'm able to go up to 647 threads and 500 concurrent connections with
> > > > >5.5.4 without any problems. chances are, it's a memory leak in the
> > > > >webapp. only way to know for sure is to profile the application.
> > > > >
> > > > >peter lin
> > > > >
> > > > >
> > > > >On 4/20/05, Tim Funk <fu...@joedog.org> wrote:
> > > > > > There are no limits in tomcat.
> > > > > > http://jakarta.apache.org/tomcat/faq/memory.html
> > > > > >
> > > > > > -Tim
> > > > > >
> > > > > > LeeAnn Pultz wrote:
> > > > > >
> > > > > > > I have a tomcat server with multiple copies of our web
> application
> > > > > > > running. We are running into what seems to be a hard-coded limit
> > > on the
> > > > > > > number of threads available to the Tomcat application.
> > > > > > >
> > > > > > > I have added code to our servlet class which prints out the
> number of
> > > > > > > active threads whenever I initialize the servlet. On Red Hat
> Linux
> > > > > > > boxes, whenever we start up enough copies of the servlet to
> hit 100
> > > > > > > active threads, we reach an OutOfMemoryError - regardless of the
> > > Xms/Xmx
> > > > > > > settings (memory profiling shows that we have plenty of memory
> > > > > > > available). On Windows XP, 50 seems to be the magic number.
> > > > > > >
> > > > > > > I have tried tweaking Xss parameters, my ulimit command in Linux
> > > shows
> > > > > > > "unlimited" - and I have reached the same results with Tomcat
> 3.3.1,
> > > > > > > 4.0.28 and 5.0.28 using Java 1.4.1 and 1.4.2. When I use
> > > WebLogic 8.1
> > > > > > > on the same Linux box, I reach 241 active threads with no
> problems
> > > > > > > whatsoever (stopped my testing at that number) so it does not
> > > seem to be
> > > > > > > an o/s limitation, or a java limitation - which leads me to
> believe
> > > > > > > there is something in Tomcat?
> > > > > > >
> > > > > > > Is the number of threads available to tomcat hard coded
> somewhere? Is
> > > > > > > there a parameter or configuration setting that I can change to
> > > increase
> > > > > > > this?
> > > > > > >
> > > > > > > If this question is better off posted to the developers list,
> please
> > > > > > > someone, let me know :)
> > > > > > >
> > > > > >
> > > > > >
> ---------------------------------------------------------------------
> > > > > > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > > > > For additional commands, e-mail:
> tomcat-user-help@jakarta.apache.org
> > > > > >
> > > > > >
> > > > >
> > > > >---------------------------------------------------------------------
> > > > >To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > > >For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > > >
> > > > LeeAnn Pultz
> > > > ExtraView Corporation
> > > > leeann@extraview.com
> > > > 831-461-7100 x115
> > > >
> > > >
> > > > ---------------------------------------------------------------------
> > > > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > > >
> > > >
> > >
> > >---------------------------------------------------------------------
> > >To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > >For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> >
> > LeeAnn Pultz
> > ExtraView Corporation
> > leeann@extraview.com
> > 831-461-7100 x115
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> >
> >
>
>---------------------------------------------------------------------
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LeeAnn Pultz
ExtraView Corporation
leeann@extraview.com
831-461-7100 x115
---------------------------------------------------------------------
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Re: OutOfMemoryError - 100 thread limit?
Posted by Peter Lin <wo...@gmail.com>.
that is some really odd behavior coming from Tomcat. I've probably run
over 1K benchmarks on Tomcat over the last 3 years and I've yet to see
that kind of behavior. Here are some random ideas to try, which I've
used in the past. They may not help, but I figure it wouldn't hurt to
suggest them.
use jmeter to send 250 requests with 25 threads against the index page.
then view the status in tomcat 5.5.4. Over time, you should see the
number of threads drop to the minimum. Under normal conditions, tomcat
will create enough threads to service those threads. after a few
minutes, the thread count should drop. If it doesn't, it means
something is keeping the connection open. if you see that, it is most
likley an application bug. Another idea is to do netstat and see what
the status of the connections are. It might be some of the
connections are not closing.
peter
On 4/20/05, LeeAnn Pultz <le...@extraview.com> wrote:
> We have no jsps in the application. The index.html page loads our servlet
> class, and I've put logging of active number of threads at the beginning of
> the servlet ini() and the very end of the service() methods in that servlet
> class. The application initializes, but we aren't doing any of the real
> "work" of rendering dynamic pages or talking to the database at this point.
>
> I get the same results whether my Xmx is 84 megs or 512 megs - we're just
> not using that much memory.
>
>
> At 08:48 AM 4/20/2005, Peter Lin wrote:
> >that sounds very odd. so if I understand correctly. this happens when
> >you hit the login page. I assume this don't happen with a static html
> >page? by any chance are you using jsp tags or some web framework?
> >
> >peter
> >
> >
> >On 4/20/05, LeeAnn Pultz <le...@extraview.com> wrote:
> > > This is not a memory leak in the application - we have hooked up a profiler
> > > to the application and watched the actual memory usage when causing this
> > > issue to happen. We have lots of memory available, are nowhere near the
> > > Xmx limit, and the machine has lots of memory available over and above the
> > > Xmx limit.
> > >
> > > In fact, I can cause the error to happen every single time, simply by
> > > hitting the first web page (login page) of the application - I don't have
> > > to log in, or do any "work". All I have to do to get the error to happen
> > > is hit 18-19 different instances of the web application, watch the Active
> > > thread count go up to 100 and tip over the tomcat.
> > >
> > > We've gone through all of the suggested infomation out on the web - we've
> > > tweaked the Xms, Xmx and Xss parameters - none of these changes made any
> > > difference, since we're not actually running out of memory. I've
> > > reproduced this on 3 different machines, all running Red Hat Linux ES 3.0 -
> > > both with LD_ASSUME_KERNEL 2.4.19 and without, so the Linux threading model
> > > doesn't seem to affect the problem.
> > >
> > >
> > > At 04:16 AM 4/20/2005, you wrote:
> > > >I'm able to go up to 647 threads and 500 concurrent connections with
> > > >5.5.4 without any problems. chances are, it's a memory leak in the
> > > >webapp. only way to know for sure is to profile the application.
> > > >
> > > >peter lin
> > > >
> > > >
> > > >On 4/20/05, Tim Funk <fu...@joedog.org> wrote:
> > > > > There are no limits in tomcat.
> > > > > http://jakarta.apache.org/tomcat/faq/memory.html
> > > > >
> > > > > -Tim
> > > > >
> > > > > LeeAnn Pultz wrote:
> > > > >
> > > > > > I have a tomcat server with multiple copies of our web application
> > > > > > running. We are running into what seems to be a hard-coded limit
> > on the
> > > > > > number of threads available to the Tomcat application.
> > > > > >
> > > > > > I have added code to our servlet class which prints out the number of
> > > > > > active threads whenever I initialize the servlet. On Red Hat Linux
> > > > > > boxes, whenever we start up enough copies of the servlet to hit 100
> > > > > > active threads, we reach an OutOfMemoryError - regardless of the
> > Xms/Xmx
> > > > > > settings (memory profiling shows that we have plenty of memory
> > > > > > available). On Windows XP, 50 seems to be the magic number.
> > > > > >
> > > > > > I have tried tweaking Xss parameters, my ulimit command in Linux
> > shows
> > > > > > "unlimited" - and I have reached the same results with Tomcat 3.3.1,
> > > > > > 4.0.28 and 5.0.28 using Java 1.4.1 and 1.4.2. When I use
> > WebLogic 8.1
> > > > > > on the same Linux box, I reach 241 active threads with no problems
> > > > > > whatsoever (stopped my testing at that number) so it does not
> > seem to be
> > > > > > an o/s limitation, or a java limitation - which leads me to believe
> > > > > > there is something in Tomcat?
> > > > > >
> > > > > > Is the number of threads available to tomcat hard coded somewhere? Is
> > > > > > there a parameter or configuration setting that I can change to
> > increase
> > > > > > this?
> > > > > >
> > > > > > If this question is better off posted to the developers list, please
> > > > > > someone, let me know :)
> > > > > >
> > > > >
> > > > > ---------------------------------------------------------------------
> > > > > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > > > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > > > >
> > > > >
> > > >
> > > >---------------------------------------------------------------------
> > > >To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > >For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > >
> > > LeeAnn Pultz
> > > ExtraView Corporation
> > > leeann@extraview.com
> > > 831-461-7100 x115
> > >
> > >
> > > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > >
> > >
> >
> >---------------------------------------------------------------------
> >To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> >For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
>
> LeeAnn Pultz
> ExtraView Corporation
> leeann@extraview.com
> 831-461-7100 x115
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
>
>
---------------------------------------------------------------------
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Re: OutOfMemoryError - 100 thread limit?
Posted by LeeAnn Pultz <le...@extraview.com>.
We have no jsps in the application. The index.html page loads our servlet
class, and I've put logging of active number of threads at the beginning of
the servlet ini() and the very end of the service() methods in that servlet
class. The application initializes, but we aren't doing any of the real
"work" of rendering dynamic pages or talking to the database at this point.
I get the same results whether my Xmx is 84 megs or 512 megs - we're just
not using that much memory.
At 08:48 AM 4/20/2005, Peter Lin wrote:
>that sounds very odd. so if I understand correctly. this happens when
>you hit the login page. I assume this don't happen with a static html
>page? by any chance are you using jsp tags or some web framework?
>
>peter
>
>
>On 4/20/05, LeeAnn Pultz <le...@extraview.com> wrote:
> > This is not a memory leak in the application - we have hooked up a profiler
> > to the application and watched the actual memory usage when causing this
> > issue to happen. We have lots of memory available, are nowhere near the
> > Xmx limit, and the machine has lots of memory available over and above the
> > Xmx limit.
> >
> > In fact, I can cause the error to happen every single time, simply by
> > hitting the first web page (login page) of the application - I don't have
> > to log in, or do any "work". All I have to do to get the error to happen
> > is hit 18-19 different instances of the web application, watch the Active
> > thread count go up to 100 and tip over the tomcat.
> >
> > We've gone through all of the suggested infomation out on the web - we've
> > tweaked the Xms, Xmx and Xss parameters - none of these changes made any
> > difference, since we're not actually running out of memory. I've
> > reproduced this on 3 different machines, all running Red Hat Linux ES 3.0 -
> > both with LD_ASSUME_KERNEL 2.4.19 and without, so the Linux threading model
> > doesn't seem to affect the problem.
> >
> >
> > At 04:16 AM 4/20/2005, you wrote:
> > >I'm able to go up to 647 threads and 500 concurrent connections with
> > >5.5.4 without any problems. chances are, it's a memory leak in the
> > >webapp. only way to know for sure is to profile the application.
> > >
> > >peter lin
> > >
> > >
> > >On 4/20/05, Tim Funk <fu...@joedog.org> wrote:
> > > > There are no limits in tomcat.
> > > > http://jakarta.apache.org/tomcat/faq/memory.html
> > > >
> > > > -Tim
> > > >
> > > > LeeAnn Pultz wrote:
> > > >
> > > > > I have a tomcat server with multiple copies of our web application
> > > > > running. We are running into what seems to be a hard-coded limit
> on the
> > > > > number of threads available to the Tomcat application.
> > > > >
> > > > > I have added code to our servlet class which prints out the number of
> > > > > active threads whenever I initialize the servlet. On Red Hat Linux
> > > > > boxes, whenever we start up enough copies of the servlet to hit 100
> > > > > active threads, we reach an OutOfMemoryError - regardless of the
> Xms/Xmx
> > > > > settings (memory profiling shows that we have plenty of memory
> > > > > available). On Windows XP, 50 seems to be the magic number.
> > > > >
> > > > > I have tried tweaking Xss parameters, my ulimit command in Linux
> shows
> > > > > "unlimited" - and I have reached the same results with Tomcat 3.3.1,
> > > > > 4.0.28 and 5.0.28 using Java 1.4.1 and 1.4.2. When I use
> WebLogic 8.1
> > > > > on the same Linux box, I reach 241 active threads with no problems
> > > > > whatsoever (stopped my testing at that number) so it does not
> seem to be
> > > > > an o/s limitation, or a java limitation - which leads me to believe
> > > > > there is something in Tomcat?
> > > > >
> > > > > Is the number of threads available to tomcat hard coded somewhere? Is
> > > > > there a parameter or configuration setting that I can change to
> increase
> > > > > this?
> > > > >
> > > > > If this question is better off posted to the developers list, please
> > > > > someone, let me know :)
> > > > >
> > > >
> > > > ---------------------------------------------------------------------
> > > > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > > >
> > > >
> > >
> > >---------------------------------------------------------------------
> > >To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > >For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> >
> > LeeAnn Pultz
> > ExtraView Corporation
> > leeann@extraview.com
> > 831-461-7100 x115
> >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> >
> >
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
>For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
LeeAnn Pultz
ExtraView Corporation
leeann@extraview.com
831-461-7100 x115
---------------------------------------------------------------------
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Re: OutOfMemoryError - 100 thread limit?
Posted by Peter Lin <wo...@gmail.com>.
that sounds very odd. so if I understand correctly. this happens when
you hit the login page. I assume this don't happen with a static html
page? by any chance are you using jsp tags or some web framework?
peter
On 4/20/05, LeeAnn Pultz <le...@extraview.com> wrote:
> This is not a memory leak in the application - we have hooked up a profiler
> to the application and watched the actual memory usage when causing this
> issue to happen. We have lots of memory available, are nowhere near the
> Xmx limit, and the machine has lots of memory available over and above the
> Xmx limit.
>
> In fact, I can cause the error to happen every single time, simply by
> hitting the first web page (login page) of the application - I don't have
> to log in, or do any "work". All I have to do to get the error to happen
> is hit 18-19 different instances of the web application, watch the Active
> thread count go up to 100 and tip over the tomcat.
>
> We've gone through all of the suggested infomation out on the web - we've
> tweaked the Xms, Xmx and Xss parameters - none of these changes made any
> difference, since we're not actually running out of memory. I've
> reproduced this on 3 different machines, all running Red Hat Linux ES 3.0 -
> both with LD_ASSUME_KERNEL 2.4.19 and without, so the Linux threading model
> doesn't seem to affect the problem.
>
>
> At 04:16 AM 4/20/2005, you wrote:
> >I'm able to go up to 647 threads and 500 concurrent connections with
> >5.5.4 without any problems. chances are, it's a memory leak in the
> >webapp. only way to know for sure is to profile the application.
> >
> >peter lin
> >
> >
> >On 4/20/05, Tim Funk <fu...@joedog.org> wrote:
> > > There are no limits in tomcat.
> > > http://jakarta.apache.org/tomcat/faq/memory.html
> > >
> > > -Tim
> > >
> > > LeeAnn Pultz wrote:
> > >
> > > > I have a tomcat server with multiple copies of our web application
> > > > running. We are running into what seems to be a hard-coded limit on the
> > > > number of threads available to the Tomcat application.
> > > >
> > > > I have added code to our servlet class which prints out the number of
> > > > active threads whenever I initialize the servlet. On Red Hat Linux
> > > > boxes, whenever we start up enough copies of the servlet to hit 100
> > > > active threads, we reach an OutOfMemoryError - regardless of the Xms/Xmx
> > > > settings (memory profiling shows that we have plenty of memory
> > > > available). On Windows XP, 50 seems to be the magic number.
> > > >
> > > > I have tried tweaking Xss parameters, my ulimit command in Linux shows
> > > > "unlimited" - and I have reached the same results with Tomcat 3.3.1,
> > > > 4.0.28 and 5.0.28 using Java 1.4.1 and 1.4.2. When I use WebLogic 8.1
> > > > on the same Linux box, I reach 241 active threads with no problems
> > > > whatsoever (stopped my testing at that number) so it does not seem to be
> > > > an o/s limitation, or a java limitation - which leads me to believe
> > > > there is something in Tomcat?
> > > >
> > > > Is the number of threads available to tomcat hard coded somewhere? Is
> > > > there a parameter or configuration setting that I can change to increase
> > > > this?
> > > >
> > > > If this question is better off posted to the developers list, please
> > > > someone, let me know :)
> > > >
> > >
> > > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > >
> > >
> >
> >---------------------------------------------------------------------
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> >For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
>
> LeeAnn Pultz
> ExtraView Corporation
> leeann@extraview.com
> 831-461-7100 x115
>
>
> ---------------------------------------------------------------------
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>
>
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Re: OutOfMemoryError - 100 thread limit?
Posted by LeeAnn Pultz <le...@extraview.com>.
This is not a memory leak in the application - we have hooked up a profiler
to the application and watched the actual memory usage when causing this
issue to happen. We have lots of memory available, are nowhere near the
Xmx limit, and the machine has lots of memory available over and above the
Xmx limit.
In fact, I can cause the error to happen every single time, simply by
hitting the first web page (login page) of the application - I don't have
to log in, or do any "work". All I have to do to get the error to happen
is hit 18-19 different instances of the web application, watch the Active
thread count go up to 100 and tip over the tomcat.
We've gone through all of the suggested infomation out on the web - we've
tweaked the Xms, Xmx and Xss parameters - none of these changes made any
difference, since we're not actually running out of memory. I've
reproduced this on 3 different machines, all running Red Hat Linux ES 3.0 -
both with LD_ASSUME_KERNEL 2.4.19 and without, so the Linux threading model
doesn't seem to affect the problem.
At 04:16 AM 4/20/2005, you wrote:
>I'm able to go up to 647 threads and 500 concurrent connections with
>5.5.4 without any problems. chances are, it's a memory leak in the
>webapp. only way to know for sure is to profile the application.
>
>peter lin
>
>
>On 4/20/05, Tim Funk <fu...@joedog.org> wrote:
> > There are no limits in tomcat.
> > http://jakarta.apache.org/tomcat/faq/memory.html
> >
> > -Tim
> >
> > LeeAnn Pultz wrote:
> >
> > > I have a tomcat server with multiple copies of our web application
> > > running. We are running into what seems to be a hard-coded limit on the
> > > number of threads available to the Tomcat application.
> > >
> > > I have added code to our servlet class which prints out the number of
> > > active threads whenever I initialize the servlet. On Red Hat Linux
> > > boxes, whenever we start up enough copies of the servlet to hit 100
> > > active threads, we reach an OutOfMemoryError - regardless of the Xms/Xmx
> > > settings (memory profiling shows that we have plenty of memory
> > > available). On Windows XP, 50 seems to be the magic number.
> > >
> > > I have tried tweaking Xss parameters, my ulimit command in Linux shows
> > > "unlimited" - and I have reached the same results with Tomcat 3.3.1,
> > > 4.0.28 and 5.0.28 using Java 1.4.1 and 1.4.2. When I use WebLogic 8.1
> > > on the same Linux box, I reach 241 active threads with no problems
> > > whatsoever (stopped my testing at that number) so it does not seem to be
> > > an o/s limitation, or a java limitation - which leads me to believe
> > > there is something in Tomcat?
> > >
> > > Is the number of threads available to tomcat hard coded somewhere? Is
> > > there a parameter or configuration setting that I can change to increase
> > > this?
> > >
> > > If this question is better off posted to the developers list, please
> > > someone, let me know :)
> > >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> >
> >
>
>---------------------------------------------------------------------
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LeeAnn Pultz
ExtraView Corporation
leeann@extraview.com
831-461-7100 x115
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Re: OutOfMemoryError - 100 thread limit?
Posted by Peter Lin <wo...@gmail.com>.
I'm able to go up to 647 threads and 500 concurrent connections with
5.5.4 without any problems. chances are, it's a memory leak in the
webapp. only way to know for sure is to profile the application.
peter lin
On 4/20/05, Tim Funk <fu...@joedog.org> wrote:
> There are no limits in tomcat.
> http://jakarta.apache.org/tomcat/faq/memory.html
>
> -Tim
>
> LeeAnn Pultz wrote:
>
> > I have a tomcat server with multiple copies of our web application
> > running. We are running into what seems to be a hard-coded limit on the
> > number of threads available to the Tomcat application.
> >
> > I have added code to our servlet class which prints out the number of
> > active threads whenever I initialize the servlet. On Red Hat Linux
> > boxes, whenever we start up enough copies of the servlet to hit 100
> > active threads, we reach an OutOfMemoryError - regardless of the Xms/Xmx
> > settings (memory profiling shows that we have plenty of memory
> > available). On Windows XP, 50 seems to be the magic number.
> >
> > I have tried tweaking Xss parameters, my ulimit command in Linux shows
> > "unlimited" - and I have reached the same results with Tomcat 3.3.1,
> > 4.0.28 and 5.0.28 using Java 1.4.1 and 1.4.2. When I use WebLogic 8.1
> > on the same Linux box, I reach 241 active threads with no problems
> > whatsoever (stopped my testing at that number) so it does not seem to be
> > an o/s limitation, or a java limitation - which leads me to believe
> > there is something in Tomcat?
> >
> > Is the number of threads available to tomcat hard coded somewhere? Is
> > there a parameter or configuration setting that I can change to increase
> > this?
> >
> > If this question is better off posted to the developers list, please
> > someone, let me know :)
> >
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
>
>
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Re: OutOfMemoryError - 100 thread limit?
Posted by Tim Funk <fu...@joedog.org>.
There are no limits in tomcat.
http://jakarta.apache.org/tomcat/faq/memory.html
-Tim
LeeAnn Pultz wrote:
> I have a tomcat server with multiple copies of our web application
> running. We are running into what seems to be a hard-coded limit on the
> number of threads available to the Tomcat application.
>
> I have added code to our servlet class which prints out the number of
> active threads whenever I initialize the servlet. On Red Hat Linux
> boxes, whenever we start up enough copies of the servlet to hit 100
> active threads, we reach an OutOfMemoryError - regardless of the Xms/Xmx
> settings (memory profiling shows that we have plenty of memory
> available). On Windows XP, 50 seems to be the magic number.
>
> I have tried tweaking Xss parameters, my ulimit command in Linux shows
> "unlimited" - and I have reached the same results with Tomcat 3.3.1,
> 4.0.28 and 5.0.28 using Java 1.4.1 and 1.4.2. When I use WebLogic 8.1
> on the same Linux box, I reach 241 active threads with no problems
> whatsoever (stopped my testing at that number) so it does not seem to be
> an o/s limitation, or a java limitation - which leads me to believe
> there is something in Tomcat?
>
> Is the number of threads available to tomcat hard coded somewhere? Is
> there a parameter or configuration setting that I can change to increase
> this?
>
> If this question is better off posted to the developers list, please
> someone, let me know :)
>
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Which connector to use, and how to build
Posted by Daxin Zuo <dz...@techexcel.com>.
Please help
Computer: UNIX Sparc 2.9
Apache 2.0.54
Tomcat 5.0.28
Please tell me what connector to use. I see the jk2 is in history. The last
version it supports is 2.0.43.
I downloaded the jakarta-tomcat-connectors-1.2.10-src.tar, it is difficult
to find a clear instruction for the build process.
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