Thank you very much for the advice Jeff. I'll have a go at that. We *are*
using a thread pool
to run threads that make connections to our database but we have Tomcat in
standalone mode.
The Tomcat documentation describes setting the max_threads, etc of the ajpv12
connector but
i'd suppose the other connectors would have the same/similar syntax.
Cheers
AndyM
Jeff Kilbride wrote:
> I saw something on the dev list about Tomcat's default thread limit and how,
> under load, Apache processes could get "stuck" waiting for a Tomcat thread
> to become available.
>
> Have you changed any of the threading defaults in your server.xml file?
> Check out the Tomcat Users Guide here:
>
> http://jakarta.apache.org/tomcat/jakarta-tomcat/src/doc/index.html
>
> and do a find for the phrase "max_threads". It shows you how to configure
> min, max, and spare threads in Tomcat's thread pool and talks about the
> default values. If you up these values, maybe that will help.
>
> Thanks,
> --jeff
>
> ----- Original Message -----
> From: "Bill Graham" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, April 26, 2001 11:50 AM
> Subject: RE: 2 Critical Problems with Tomcat 3.2.x
>
> > I've also been experienceing a lot of the Number 2 problem described
> > where Tomcat stops responding to http requests and I can't figure out
> > what's causing it. I've been able to reproduce the problem with multiple
> > VMs on both Linux and Solaris machines. I applied the patch for Tomcat
> > bug #1006 and the hanging still occurs.
> >
> > I haven't come across any responses to Andy's first post so I thought
> > I'd ask again. Anyone have any idea what's causing this?
> >
> > thanks,
> > Bill
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Andrew McDonald
> > Sent: Sunday, April 22, 2001 10:56 PM
> > To: [EMAIL PROTECTED]
> > Subject: 2 Critical Problems with Tomcat 3.2.x
> >
> >
> > Hi there,
> >
> > First I'd like to thank the developers for a great product. Tomcat is a
> > nice piece of software. And like all great OSS, very easy to raise a
> > purchase order for ;) Thanks guys.
> > Unfortunately I have run into a couple of serious show-stoppers when
> > deploying TC in production.
> > A bit of background:
> > We have been running various incarnations of JServ and Tomcat over the
> > past 12 months or so.
> > We have 3 Application Servers: Two Compaq Deskpro PII/450s and one
> > PIII/500 with 128MB Ram each. They are running Linux, kernel is 2.2.19,
> > glibc-2.1.3. We are currently running various incarnations of TC3.2.x
> > We run a Stock Trading Forum, which is made up of Servlets and JSPs.
> > You can see it at http://www.hotcopper.com.au if you're interested at
> > all. We are one of the most hit websites in Australia according to
> > www.top100.com.au.
> >
> > We have tested Tomcat with the Solaris 1.3 JVM, IBM 1.3 JVM and
> > Blackdown 1.3 JVM (FCS). I'm happiest with Blackdown. It *seems* to
> > have the best performance.
> >
> > On to the problems:
> > 1. We dubbed this one "The Apache White Screen" problem. We connected
> > Tomcat to various versions of Apache <=1.14 in the standard way
> > (mod_jk.so) Symptom: People using Internet Explorer to browse our site
> > will intermittently get a white/ blank screen instead of results from
> > our application. When this happens, we believe the request doesn't even
> > enter the java code, so it may be a problem with the connector. I seem
> > to recall (sorry this was about 8 months ago) Apache returning a 304 or
> > a 302. I haven't re-tested this in a while, I was just wondering
> > whether people were aware of this problem in the past and had already
> > looked into it and possibly fixed it.
> > Our "solution" was to run Tomcat standalone, which seemed to solve this
> > issue.
> >
> > 2. We dubbed this one "The 132 Thread" Problem, even though it doesn't
> > always happen with 132 threads; sometimes 128, 130, or if using the
> > Blackdown JVM, 134. (wierd). We use NATIVE threads. Symptom: Tomcat
> > stops responding to http requests after a certain number (~132) of
> > threads is reached. When this happens it will either deadlock or
> > segfault. During this time the box is fine, and to solve it temporarily
> > I just need to kill all the java processes and restart Tomcat. This
> > problem occurs regardless of JVM and the version of the Linux Kernel
> > doesn't seem to make a difference. It happens once or twice a week.
> >
> > Assistance with either of these problems would be greatly appreciated.
> > Number 2 is the really important one but information regarding number 1
> > would be great as well.
> >
> > Of course if you need more information please get back to me.
> >
> > Oh, and btw, yes I realise that running Compaq desktops in production
> > isn't the best idea ;) That will be attended to.
> >
> > Thanks in advance
> >
> > Cheers
> >
> > --
> > Andrew McDonald "We cannot reason ourselves out of our
> basic
> > Systems Administration irrationality. All we can do is learn the
> art
> > HOTcopper Australia of being irrational in a reasonable way."
> > http://www.hotcopper.com.au - Huxley
> >
> >
