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Posted to users@tomcat.apache.org by Billy Ng <bi...@gmail.com> on 2008/06/05 22:25:10 UTC
Tomcat having problems under load
Hi folks,
I am using Tomcat 5.5.20 on a Linux box with 8 CPUs and 8GB of RAM. I am seeing a really strange behavior. The web app has 1 very heavy load servlet, but I notice only 1 CPU is busy. Then, the Tomcat is only up for 15 minutes and die. Any thing I should look at?
Thanks in advance!
Billy Ng
Re: Tomcat having problems under load
Posted by Johnny Kewl <jo...@kewlstuff.co.za>.
Billy, nothing on TV so I playing here ;)
You need to collect some info and explain the details... so if I guess
wrong, the gurus can help you later ;)
When you say Tomcat up for 15 mins and dies... does tomcat crash?... is
there an error log, if so get it ready and post it?
Or is it just a browser error page?
When you say strange behaviour... is this something that was working and
suddenly stopped working or is it a new installation?
Either way post your JK worker and mounts and connector configuration.
I think 2 possibe problems...
Either the "heavy servlet" has a problem and via a lock or bad sync, or
something else... its just not getting through the code, stuck in a wait.
Or your JK connection is screwed and the connection is just not getting
thru...
Put Tomcat back on port 8080 (add the connector back) if its not there....
and see if the servlet works on port 8080
If not... it is the servlet... if it works on 8080... your JK connector is
screwed.
If servlet is screwed, then put the thing back into the debugger... Netbeans
whatever, and try find the block, lock, loop whatever... threading can be
tricky.
So thats what you got to do.... the problem as I "guess" it, is that the
connection is not getting thru, the browser is hanging around waiting for
Tomcat to do something and eventually says... I give up, after 15 mins....
which suggests a bad JK config.
I think the reason you see one CPU being scheduled is because one thread is
allocated and then it gets stuck... If you do another browser I think you'll
see the next thread allocated to the next CPU and that will also get
stuck... something like that... I wouldnt worry about the CPU utilization
until the thing actually works...
I've never had a problem like this... so try the above, and if you dont come
right, come back here with "lots of feedback" ;)
Thanks for the machine info btw... its a dual quad, I think... I dont know
of any board with 8 physical processors... just wanted to see it, if it did
exist... ha ha
Good luck
----- Original Message -----
From: "Billy Ng" <bi...@gmail.com>
To: "Tomcat Users List" <us...@tomcat.apache.org>
Sent: Saturday, June 07, 2008 1:46 AM
Subject: Re: Tomcat having problems under load
> It is a Dell box. Only my IT knows the detail. The Linux is 64-bit and
> java has 5GB in the heap. It should be enough. The Tomcat never runs out
> of memory. Al least, I do not see it in the logs. I would not think it
> is a memory issue. We are using apache+mod_jk_+tomcat. I wonder if the
> mod_jk or garbarge collection fails me.
>>
>> I am using Tomcat 5.5.20 on a Linux box with 8 CPUs and 8GB of RAM. I am
>> seeing a really strange behavior. The web app has 1 very heavy load
>> servlet, but I notice only 1 CPU is busy. Then, the Tomcat is only up
>> for 15 minutes and die. Any thing I should look at?
>>
>> Thanks in advance!
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Re: Tomcat having problems under load
Posted by Billy Ng <bi...@gmail.com>.
It is a Dell box. Only my IT knows the detail. The Linux is 64-bit and
java has 5GB in the heap. It should be enough. The Tomcat never runs out
of memory. Al least, I do not see it in the logs. I would not think it is
a memory issue. We are using apache+mod_jk_+tomcat. I wonder if the mod_jk
or garbarge collection fails me.
Billy Ng
----- Original Message -----
From: "Johnny Kewl" <jo...@kewlstuff.co.za>
To: "Tomcat Users List" <us...@tomcat.apache.org>
Sent: Friday, June 06, 2008 10:11 AM
Subject: Re: Tomcat having problems under load
>
> ----- Original Message -----
> From: "Billy Ng" <bi...@gmail.com>
> To: "Tomcat Users List" <us...@tomcat.apache.org>
> Sent: Thursday, June 05, 2008 10:25 PM
> Subject: Tomcat having problems under load
>
>
> Hi folks,
>
> I am using Tomcat 5.5.20 on a Linux box with 8 CPUs and 8GB of RAM. I am
> seeing a really strange behavior. The web app has 1 very heavy load
> servlet, but I notice only 1 CPU is busy. Then, the Tomcat is only up for
> 15 minutes and die. Any thing I should look at?
>
> Thanks in advance!
>
> Billy,
>
> Dont know, my guess the heavy servlet has issues, check mem, logs, threads
> etc... and chuck will probably set you right ;)
> I just want to know about the box ;) Where did you get Godzilla? ;) Would
> luv to have a squiz at the monster you have there.
> Didnt even know bios, linux would see a monster with 8 cpus... a link to
> the supplier would be nice, thanks.
> Is it all for this servlet? Wow!
>
>
> ---------------------------------------------------------------------------
> HARBOR : http://www.kewlstuff.co.za/index.htm
> The most powerful application server on earth.
> The only real POJO Application Server.
> See it in Action : http://www.kewlstuff.co.za/cd_tut_swf/whatisejb1.htm
> ---------------------------------------------------------------------------
>
>
> ---------------------------------------------------------------------
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
> For additional commands, e-mail: users-help@tomcat.apache.org
>
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Re: Tomcat having problems under load
Posted by Johnny Kewl <jo...@kewlstuff.co.za>.
----- Original Message -----
From: "Billy Ng" <bi...@gmail.com>
To: "Tomcat Users List" <us...@tomcat.apache.org>
Sent: Thursday, June 05, 2008 10:25 PM
Subject: Tomcat having problems under load
Hi folks,
I am using Tomcat 5.5.20 on a Linux box with 8 CPUs and 8GB of RAM. I am
seeing a really strange behavior. The web app has 1 very heavy load
servlet, but I notice only 1 CPU is busy. Then, the Tomcat is only up for
15 minutes and die. Any thing I should look at?
Thanks in advance!
Billy,
Dont know, my guess the heavy servlet has issues, check mem, logs, threads
etc... and chuck will probably set you right ;)
I just want to know about the box ;) Where did you get Godzilla? ;) Would
luv to have a squiz at the monster you have there.
Didnt even know bios, linux would see a monster with 8 cpus... a link to the
supplier would be nice, thanks.
Is it all for this servlet? Wow!
---------------------------------------------------------------------------
HARBOR : http://www.kewlstuff.co.za/index.htm
The most powerful application server on earth.
The only real POJO Application Server.
See it in Action : http://www.kewlstuff.co.za/cd_tut_swf/whatisejb1.htm
---------------------------------------------------------------------------
---------------------------------------------------------------------
To start a new topic, e-mail: users@tomcat.apache.org
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