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Posted to users@tomcat.apache.org by Stuart Stephen <st...@talkics.com> on 2003/09/17 13:40:51 UTC
Tomcat on Dual CPU Server
Hi,
I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
noticed that it only uses 1 cpu. How can I make it use both? Is this a linux
thing or a tomcat thing?
Regards,
Stuart Stephen
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Re: Tomcat on Dual CPU Server
Posted by Jaco Kroon <jk...@cs.up.ac.za>.
It would either be the JVM, but apps are usually rather ignorant of the
fact that it is running on one or more CPU's, so it's probably linux. I
would try and determine whether other, multi-threaded, apps only use one
cpu as well, if so, then it is deffinately the OS, if other multi-threaded
apps use both cpu's, then check that you are not perhaps just thinking
that it is using one CPU, remember that if your webapp runs in a single
thread, then it will only use one CPU.
On Wed, 17 Sep 2003, Stuart Stephen wrote:
> Hi,
>
> I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> noticed that it only uses 1 cpu. How can I make it use both? Is this a linux
> thing or a tomcat thing?
>
> Regards,
> Stuart Stephen
>
>
>
> ---------------------------------------------------------------------
> 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: Tomcat on Dual CPU Server
Posted by Stuart Stephen <st...@talkics.com>.
Ahh, I wondered if that was what you meant. I'll have to experiment further.
Thanks.
-----Original Message-----
From: Jaco Kroon [mailto:jkroon@cs.up.ac.za]
Sent: 17 September 2003 12:59
To: Tomcat Users List
Subject: RE: Tomcat on Dual CPU Server
That would be correct, as I mentioned in my other mail, a single thread
can only run on one CPU, thus to get to 100% cpu usage, you need at least
two threads performing two concurrent "infinite loops". A single loop
cannot push 2 cpu's to over 50% as the one cpu will run the loop and the
other will sit idle, and every now and again do some arb work.
On Wed, 17 Sep 2003, Stuart Stephen wrote:
> Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that
multi-threaded
> CPU's would be supported in Sun's Java VM. However, if i put tomcat into
an
> infinite loop it seems to go only to just above 50% CPU for the whole
> system.
>
> -----Original Message-----
> From: Tim Funk [mailto:funkman@joedog.org]
> Sent: 17 September 2003 12:49
> To: Tomcat Users List
> Subject: Re: Tomcat on Dual CPU Server
>
>
> The JVM is spec'd to be able to run on multiple processors transparently
and
> an Java application. (Ignoring natvie code issues) Whether the
> *implementation* of a JVM takes advantage of a multi-cpu system is a job
of
> the JVM vendor.
>
> -Tim
>
> Stuart Stephen wrote:
>
> > Hi,
> >
> > I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> > noticed that it only uses 1 cpu. How can I make it use both? Is this a
> linux
> > thing or a tomcat thing?
> >
>
>
> ---------------------------------------------------------------------
> 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
>
>
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RE: Tomcat on Dual CPU Server
Posted by Stuart Stephen <st...@talkics.com>.
Ahh, I wondered if that was what you meant. I'll have to experiment further.
Thanks.
-----Original Message-----
From: Jaco Kroon [mailto:jkroon@cs.up.ac.za]
Sent: 17 September 2003 12:59
To: Tomcat Users List
Subject: RE: Tomcat on Dual CPU Server
That would be correct, as I mentioned in my other mail, a single thread
can only run on one CPU, thus to get to 100% cpu usage, you need at least
two threads performing two concurrent "infinite loops". A single loop
cannot push 2 cpu's to over 50% as the one cpu will run the loop and the
other will sit idle, and every now and again do some arb work.
On Wed, 17 Sep 2003, Stuart Stephen wrote:
> Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that
multi-threaded
> CPU's would be supported in Sun's Java VM. However, if i put tomcat into
an
> infinite loop it seems to go only to just above 50% CPU for the whole
> system.
>
> -----Original Message-----
> From: Tim Funk [mailto:funkman@joedog.org]
> Sent: 17 September 2003 12:49
> To: Tomcat Users List
> Subject: Re: Tomcat on Dual CPU Server
>
>
> The JVM is spec'd to be able to run on multiple processors transparently
and
> an Java application. (Ignoring natvie code issues) Whether the
> *implementation* of a JVM takes advantage of a multi-cpu system is a job
of
> the JVM vendor.
>
> -Tim
>
> Stuart Stephen wrote:
>
> > Hi,
> >
> > I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> > noticed that it only uses 1 cpu. How can I make it use both? Is this a
> linux
> > thing or a tomcat thing?
> >
>
>
> ---------------------------------------------------------------------
> 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
>
>
---------------------------------------------------------------------
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---------------------------------------------------------------------
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RE: Tomcat on Dual CPU Server
Posted by Jaco Kroon <jk...@cs.up.ac.za>.
That would be correct, as I mentioned in my other mail, a single thread
can only run on one CPU, thus to get to 100% cpu usage, you need at least
two threads performing two concurrent "infinite loops". A single loop
cannot push 2 cpu's to over 50% as the one cpu will run the loop and the
other will sit idle, and every now and again do some arb work.
On Wed, 17 Sep 2003, Stuart Stephen wrote:
> Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded
> CPU's would be supported in Sun's Java VM. However, if i put tomcat into an
> infinite loop it seems to go only to just above 50% CPU for the whole
> system.
>
> -----Original Message-----
> From: Tim Funk [mailto:funkman@joedog.org]
> Sent: 17 September 2003 12:49
> To: Tomcat Users List
> Subject: Re: Tomcat on Dual CPU Server
>
>
> The JVM is spec'd to be able to run on multiple processors transparently and
> an Java application. (Ignoring natvie code issues) Whether the
> *implementation* of a JVM takes advantage of a multi-cpu system is a job of
> the JVM vendor.
>
> -Tim
>
> Stuart Stephen wrote:
>
> > Hi,
> >
> > I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> > noticed that it only uses 1 cpu. How can I make it use both? Is this a
> linux
> > thing or a tomcat thing?
> >
>
>
> ---------------------------------------------------------------------
> 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
>
>
---------------------------------------------------------------------
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Re: Tomcat on Dual CPU Server
Posted by Tim Funk <fu...@joedog.org>.
You need 2 infinite loops to peg a dual CPU system.
-Tim
Stuart Stephen wrote:
> Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded
> CPU's would be supported in Sun's Java VM. However, if i put tomcat into an
> infinite loop it seems to go only to just above 50% CPU for the whole
> system.
>
> -----Original Message-----
> From: Tim Funk [mailto:funkman@joedog.org]
> Sent: 17 September 2003 12:49
> To: Tomcat Users List
> Subject: Re: Tomcat on Dual CPU Server
>
>
> The JVM is spec'd to be able to run on multiple processors transparently and
> an Java application. (Ignoring natvie code issues) Whether the
> *implementation* of a JVM takes advantage of a multi-cpu system is a job of
> the JVM vendor.
>
Re: Tomcat on Dual CPU Server
Posted by Tim Funk <fu...@joedog.org>.
You need 2 infinite loops to peg a dual CPU system.
-Tim
Stuart Stephen wrote:
> Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded
> CPU's would be supported in Sun's Java VM. However, if i put tomcat into an
> infinite loop it seems to go only to just above 50% CPU for the whole
> system.
>
> -----Original Message-----
> From: Tim Funk [mailto:funkman@joedog.org]
> Sent: 17 September 2003 12:49
> To: Tomcat Users List
> Subject: Re: Tomcat on Dual CPU Server
>
>
> The JVM is spec'd to be able to run on multiple processors transparently and
> an Java application. (Ignoring natvie code issues) Whether the
> *implementation* of a JVM takes advantage of a multi-cpu system is a job of
> the JVM vendor.
>
---------------------------------------------------------------------
To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
RE: Tomcat on Dual CPU Server
Posted by Jaco Kroon <jk...@cs.up.ac.za>.
That would be correct, as I mentioned in my other mail, a single thread
can only run on one CPU, thus to get to 100% cpu usage, you need at least
two threads performing two concurrent "infinite loops". A single loop
cannot push 2 cpu's to over 50% as the one cpu will run the loop and the
other will sit idle, and every now and again do some arb work.
On Wed, 17 Sep 2003, Stuart Stephen wrote:
> Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded
> CPU's would be supported in Sun's Java VM. However, if i put tomcat into an
> infinite loop it seems to go only to just above 50% CPU for the whole
> system.
>
> -----Original Message-----
> From: Tim Funk [mailto:funkman@joedog.org]
> Sent: 17 September 2003 12:49
> To: Tomcat Users List
> Subject: Re: Tomcat on Dual CPU Server
>
>
> The JVM is spec'd to be able to run on multiple processors transparently and
> an Java application. (Ignoring natvie code issues) Whether the
> *implementation* of a JVM takes advantage of a multi-cpu system is a job of
> the JVM vendor.
>
> -Tim
>
> Stuart Stephen wrote:
>
> > Hi,
> >
> > I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> > noticed that it only uses 1 cpu. How can I make it use both? Is this a
> linux
> > thing or a tomcat thing?
> >
>
>
> ---------------------------------------------------------------------
> 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
>
>
RE: Tomcat on Dual CPU Server
Posted by Stuart Stephen <st...@talkics.com>.
Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded
CPU's would be supported in Sun's Java VM. However, if i put tomcat into an
infinite loop it seems to go only to just above 50% CPU for the whole
system.
-----Original Message-----
From: Tim Funk [mailto:funkman@joedog.org]
Sent: 17 September 2003 12:49
To: Tomcat Users List
Subject: Re: Tomcat on Dual CPU Server
The JVM is spec'd to be able to run on multiple processors transparently and
an Java application. (Ignoring natvie code issues) Whether the
*implementation* of a JVM takes advantage of a multi-cpu system is a job of
the JVM vendor.
-Tim
Stuart Stephen wrote:
> Hi,
>
> I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> noticed that it only uses 1 cpu. How can I make it use both? Is this a
linux
> thing or a tomcat thing?
>
---------------------------------------------------------------------
To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
RE: Tomcat on Dual CPU Server
Posted by Stuart Stephen <st...@talkics.com>.
Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded
CPU's would be supported in Sun's Java VM. However, if i put tomcat into an
infinite loop it seems to go only to just above 50% CPU for the whole
system.
-----Original Message-----
From: Tim Funk [mailto:funkman@joedog.org]
Sent: 17 September 2003 12:49
To: Tomcat Users List
Subject: Re: Tomcat on Dual CPU Server
The JVM is spec'd to be able to run on multiple processors transparently and
an Java application. (Ignoring natvie code issues) Whether the
*implementation* of a JVM takes advantage of a multi-cpu system is a job of
the JVM vendor.
-Tim
Stuart Stephen wrote:
> Hi,
>
> I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> noticed that it only uses 1 cpu. How can I make it use both? Is this a
linux
> thing or a tomcat thing?
>
---------------------------------------------------------------------
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
Re: Tomcat on Dual CPU Server
Posted by Tim Funk <fu...@joedog.org>.
The JVM is spec'd to be able to run on multiple processors transparently and
an Java application. (Ignoring natvie code issues) Whether the
*implementation* of a JVM takes advantage of a multi-cpu system is a job of
the JVM vendor.
-Tim
Stuart Stephen wrote:
> Hi,
>
> I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> noticed that it only uses 1 cpu. How can I make it use both? Is this a linux
> thing or a tomcat thing?
>
---------------------------------------------------------------------
To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
Re: Tomcat on Dual CPU Server
Posted by Jaco Kroon <jk...@cs.up.ac.za>.
It would either be the JVM, but apps are usually rather ignorant of the
fact that it is running on one or more CPU's, so it's probably linux. I
would try and determine whether other, multi-threaded, apps only use one
cpu as well, if so, then it is deffinately the OS, if other multi-threaded
apps use both cpu's, then check that you are not perhaps just thinking
that it is using one CPU, remember that if your webapp runs in a single
thread, then it will only use one CPU.
On Wed, 17 Sep 2003, Stuart Stephen wrote:
> Hi,
>
> I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> noticed that it only uses 1 cpu. How can I make it use both? Is this a linux
> thing or a tomcat thing?
>
> Regards,
> Stuart Stephen
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
>
>
Re: Tomcat on Dual CPU Server
Posted by Tim Funk <fu...@joedog.org>.
The JVM is spec'd to be able to run on multiple processors transparently and
an Java application. (Ignoring natvie code issues) Whether the
*implementation* of a JVM takes advantage of a multi-cpu system is a job of
the JVM vendor.
-Tim
Stuart Stephen wrote:
> Hi,
>
> I've installed tomcat on a dual CPU redhat linux 9.0 machine and have
> noticed that it only uses 1 cpu. How can I make it use both? Is this a linux
> thing or a tomcat thing?
>