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Posted to users@tomcat.apache.org by Knutsen Jeffrey S <Kn...@JohnDeere.com> on 2002/06/10 17:37:32 UTC
RE: Please help me improve my question skills (number of tomcat
a pps)
Thanks very much for the help.
I do understand that there are many variables that will affect the answer to
this question. At this time, all I am really after is "what is the best
that anyone has done", in any configuration. I am interested in real-world
successes.
Thanks again!
-----Original Message-----
From: Craig R. McClanahan [mailto:craigmcc@apache.org]
Sent: Monday, June 10, 2002 10:33 AM
To: Tomcat Users List
Subject: Re: Please help me improve my question skills (number of tomcat
apps)
On Mon, 10 Jun 2002, Knutsen Jeffrey S wrote:
> Date: Mon, 10 Jun 2002 08:48:39 -0500
> From: Knutsen Jeffrey S <Kn...@JohnDeere.com>
> Reply-To: Tomcat Users List <to...@jakarta.apache.org>
> To: "'tomcat-user@jakarta.apache.org'" <to...@jakarta.apache.org>
> Subject: Please help me improve my question skills (number of tomcat apps)
>
> I have submitted the following question and received no response. I know
> this isn't a technical problem, but I was hoping for responses from real
> developers. I thought it was a simple question, and have always received
> excellent and quick responses from the tomcat mail list in the past, so
the
> problem must be with me or the way I am asking.
>
> Can someone please help me improve myself? Is this a stupid question?
Have
> I perhaps asked it incorrectly? I am open and receptive to any
constructive
> criticism available (I can take it, but maybe you could send a direct
> response if you want to be extremely brutal?!)
>
> All I really want to know is how many applications real developers are
> putting on one machine in the real world. I am just looking for an
abstract
> number, and I am not worried about system configurations at this time.
>
The problem is that there is no generally useful answer to your question
as stated. It depends even more on the nature of the applications you are
talking about (when the answer might even be zero for a particular server
configuration) as the size of the server (an answer based on a 64-CPU
mega-server with 4 gigabytes of main memory isn't going to help you on a
small single-CPU Linux box with 64 megs).
There are no architectural limits on the number of webapps a single Tomcat
instance can support, or the number of Tomcat instances on a single
server. It all comes down to what resource bottlenecks you run into first
in your application environment. In many webapp environments, the first
bottleneck encountered is often database access, followed by the number of
simultenaous requests being processed. Neither of those bottlenecks has
much directly to do with how many different webapps you are talking
about.
> Thanks!
>
Craig
>
> ORIGINAL QUESTION:
>
> I am doing some Tomcat cost/benefit projections for my company. I need to
> determine the maximum number of applications that will run on Tomcat and
> still provide stable performance. I am not interested in a theoretical
> number at this time, just seeking information about what real developers
are
> actually doing with real applications.
>
> At this time, I am not interested in what machine types, OSs,
> configurations, versions, are being used. I understand the answer to my
> questions will depend heavily on these issues as well as on the
applications
> themselves. I just need to come up with a realistic number of
> instances/apps which are being run on a single machine by real users. I am
> seeking an answer to the following two questions:
>
> Number of Tomcat instances I am running on one machine:
>
> Number of individual applications I am running in all instances of Tomcat
on
> one machine:
>
> Please feel free to respond to the mail list, or to me directly at
> knutsenjeffreys@johndeere.com (if we don't want to clog the list with
> answers to this question). I will post a final resolution message to the
> mail list when I have come to some sort of conclusion.
>
> Thanks in advance for your help!
>
>
>
>
> --
> To unsubscribe, e-mail:
> <ma...@jakarta.apache.org>
> For additional commands, e-mail:
> <ma...@jakarta.apache.org>
>
>
>
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<ma...@jakarta.apache.org>
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>
>
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Re: Please help me improve my question skills (number of tomcat a
pps)
Posted by "Craig R. McClanahan" <cr...@apache.org>.
On Mon, 10 Jun 2002, Arshad Mahmood wrote:
> Date: Mon, 10 Jun 2002 16:49:07 +0100
> From: Arshad Mahmood <ar...@compuvision.co.uk>
> Reply-To: Tomcat Users List <to...@jakarta.apache.org>
> To: Tomcat Users List <to...@jakarta.apache.org>
> Subject: Re: Please help me improve my question skills (number of tomcat
> a pps)
>
> Hi,
>
> So the question reduces to:-
> 1. What are the extra memory requirements for a virtual host/context?
> 2. How much longer does it take to decide on a servlet/jsp to invoke for
> an extra virtual host/context?
>
> >From my (limited) understanding of Tomcat, I would say the answer to both of
> these questions is negligible compared to the memory/overhead of processing
> a typical request. So your question reduces to how many requests can be
> processed by your instance, and that depends very much on your application.
> The distribution of the requests amongst the applications shouldm't matter.
>
> Can somebody more knowledgeable confirm the extra resource requirements for
> virtual hosts/contexts.
>
Virtual hosts and webapps are both looked up via Hashtables (Tomcat 3.x)
or HashMaps (Tomcat 4.x), so the cost is indeed very small - so small that
it's basically not worth worrying about for a standalone Tomcat
installation.
When you're using Tomcat behind a web connector, it really depends on how
the connector is implemented -- and someone else will have to answer those
questions; I never use 'em so don't have any idea.
> Regards,
> Arshad
>
Craig
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Re: Please help me improve my question skills (number of tomcat a pps)
Posted by Arshad Mahmood <ar...@compuvision.co.uk>.
Hi,
So the question reduces to:-
1. What are the extra memory requirements for a virtual host/context?
2. How much longer does it take to decide on a servlet/jsp to invoke for
an extra virtual host/context?
>From my (limited) understanding of Tomcat, I would say the answer to both of
these questions is negligible compared to the memory/overhead of processing
a typical request. So your question reduces to how many requests can be
processed by your instance, and that depends very much on your application.
The distribution of the requests amongst the applications shouldm't matter.
Can somebody more knowledgeable confirm the extra resource requirements for
virtual hosts/contexts.
Regards,
Arshad
----- Original Message -----
From: "Knutsen Jeffrey S" <Kn...@JohnDeere.com>
To: "'Tomcat Users List'" <to...@jakarta.apache.org>
Sent: Monday, June 10, 2002 4:37 PM
Subject: RE: Please help me improve my question skills (number of tomcat a
pps)
> Thanks very much for the help.
>
> I do understand that there are many variables that will affect the answer
to
> this question. At this time, all I am really after is "what is the best
> that anyone has done", in any configuration. I am interested in
real-world
> successes.
>
> Thanks again!
>
>
>
>
> -----Original Message-----
> From: Craig R. McClanahan [mailto:craigmcc@apache.org]
> Sent: Monday, June 10, 2002 10:33 AM
> To: Tomcat Users List
> Subject: Re: Please help me improve my question skills (number of tomcat
> apps)
>
>
>
>
> On Mon, 10 Jun 2002, Knutsen Jeffrey S wrote:
>
> > Date: Mon, 10 Jun 2002 08:48:39 -0500
> > From: Knutsen Jeffrey S <Kn...@JohnDeere.com>
> > Reply-To: Tomcat Users List <to...@jakarta.apache.org>
> > To: "'tomcat-user@jakarta.apache.org'" <to...@jakarta.apache.org>
> > Subject: Please help me improve my question skills (number of tomcat
apps)
> >
> > I have submitted the following question and received no response. I
know
> > this isn't a technical problem, but I was hoping for responses from real
> > developers. I thought it was a simple question, and have always
received
> > excellent and quick responses from the tomcat mail list in the past, so
> the
> > problem must be with me or the way I am asking.
> >
> > Can someone please help me improve myself? Is this a stupid question?
> Have
> > I perhaps asked it incorrectly? I am open and receptive to any
> constructive
> > criticism available (I can take it, but maybe you could send a direct
> > response if you want to be extremely brutal?!)
> >
> > All I really want to know is how many applications real developers are
> > putting on one machine in the real world. I am just looking for an
> abstract
> > number, and I am not worried about system configurations at this time.
> >
>
> The problem is that there is no generally useful answer to your question
> as stated. It depends even more on the nature of the applications you are
> talking about (when the answer might even be zero for a particular server
> configuration) as the size of the server (an answer based on a 64-CPU
> mega-server with 4 gigabytes of main memory isn't going to help you on a
> small single-CPU Linux box with 64 megs).
>
> There are no architectural limits on the number of webapps a single Tomcat
> instance can support, or the number of Tomcat instances on a single
> server. It all comes down to what resource bottlenecks you run into first
> in your application environment. In many webapp environments, the first
> bottleneck encountered is often database access, followed by the number of
> simultenaous requests being processed. Neither of those bottlenecks has
> much directly to do with how many different webapps you are talking
> about.
>
>
> > Thanks!
> >
>
> Craig
>
>
> >
> > ORIGINAL QUESTION:
> >
> > I am doing some Tomcat cost/benefit projections for my company. I need
to
> > determine the maximum number of applications that will run on Tomcat and
> > still provide stable performance. I am not interested in a theoretical
> > number at this time, just seeking information about what real developers
> are
> > actually doing with real applications.
> >
> > At this time, I am not interested in what machine types, OSs,
> > configurations, versions, are being used. I understand the answer to my
> > questions will depend heavily on these issues as well as on the
> applications
> > themselves. I just need to come up with a realistic number of
> > instances/apps which are being run on a single machine by real users. I
am
> > seeking an answer to the following two questions:
> >
> > Number of Tomcat instances I am running on one machine:
> >
> > Number of individual applications I am running in all instances of
Tomcat
> on
> > one machine:
> >
> > Please feel free to respond to the mail list, or to me directly at
> > knutsenjeffreys@johndeere.com (if we don't want to clog the list with
> > answers to this question). I will post a final resolution message to
the
> > mail list when I have come to some sort of conclusion.
> >
> > Thanks in advance for your help!
> >
> >
> >
> >
> > --
> > To unsubscribe, e-mail:
> > <ma...@jakarta.apache.org>
> > For additional commands, e-mail:
> > <ma...@jakarta.apache.org>
> >
> >
> >
> > --
> > To unsubscribe, e-mail:
> <ma...@jakarta.apache.org>
> > For additional commands, e-mail:
> <ma...@jakarta.apache.org>
> >
> >
>
>
> --
> To unsubscribe, e-mail:
> <ma...@jakarta.apache.org>
> For additional commands, e-mail:
> <ma...@jakarta.apache.org>
>
>
>
> --
> To unsubscribe, e-mail:
<ma...@jakarta.apache.org>
> For additional commands, e-mail:
<ma...@jakarta.apache.org>
>
--
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