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Posted to users@tomcat.apache.org by Wouter Bijlsma <j....@stud.tue.nl> on 2003/03/21 20:01:02 UTC
Connection drops with tomcat-based game server (very short version)
Is it possible that tomcat sometimes randomly kills a request, does not process a request or queues a request indefinitely, thereby blocking a client that tries to read back the response to its request? Could this be possible when a servlet communicates with the clients using only raw data and InputStreams/OutputStreams? And: is it a good idea to develop a game server for playing games like chess, chequers or draughts with tomcat, considering the fact that tomcats main purpose is to act as web application server using a strict request-response paradigm. Is it safe to assume that every request made by a client always yields a proper response, also when using raw data transfers? Also when there's a really high volume of requests to a single servlet?
Don't get me wrong: I do *not* think there's something wrong with tomcat! As a matter of fact I have really good experiences with it using it for web applications!!
Kind Regards,
Wouter Bijlsma,
j.w.bijlsma@stud.tue.nl
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Re: Connection drops with tomcat-based game server (very short
version)
Posted by Ben Ricker <br...@wellinx.com>.
One other suggestion: You might try putting Apache in front of the
Tomcat to see if it still drops the connections. If the behavior stops,
it might be something in the httpd connector. If the behavior persists,
then I would look at the app or, more likely, the other "network" access
(is there firewalls? VPN? some weird network setup?).
Ben
On Fri, 2003-03-21 at 13:51, Wouter Bijlsma wrote:
> There's nothing in the logfiles (we are only using catalina.out) that would suggest that Tomcat even knows about a connection problem. The server just goes on as if nothing happened, but the messages it sends to the 'dead client' are never delivered. This might indeed be a load/config issue, although some users experienced the problem even when only 3 users were logged in. The confusing part is that we just cannot reproduce the bug on a fast network (not even with 15 users logged in), while neither the client nor the server use time-sensitive code for sending or receiving messages.
>
> We are using tomcat 4.0.6 on a Debian/testing linux machine, kernel version 2.4.20
>
> Wouter Bijlsma
>
> On 21 Mar 2003 13:16:19 -0600
> Ben Ricker <br...@wellinx.com> wrote:
>
> > Sounds like a load issue coupled with a config issue. How about some
> > logs entries? DO you see anything in the logs you setup? Catalina.out?
> > Context log?
> >
> > Also, some idea what OS and version would also be helpful. It is nearly
> > impossible to tell (at least for me).
> >
> > Ben Ricker
> >
> > On Fri, 2003-03-21 at 13:01, Wouter Bijlsma wrote:
> > > Is it possible that tomcat sometimes randomly kills a request, does
> > > not process a request or queues a request indefinitely, thereby
> > > blocking a client that tries to read back the response to its request?
> > > Could this be possible when a servlet communicates with the clients
> > > using only raw data and InputStreams/OutputStreams? And: is it a good
> > > idea to develop a game server for playing games like chess, chequers
> > > or draughts with tomcat, considering the fact that tomcats main
> > > purpose is to act as web application server using a strict
> > > request-response paradigm. Is it safe to assume that every request
> > > made by a client always yields a proper response, also when using raw
> > > data transfers? Also when there's a really high volume of requests to
> > > a single servlet?
> > >
> > > Don't get me wrong: I do *not* think there's something wrong with
> > > tomcat! As a matter of fact I have really good experiences with it
> > > using it for web applications!!
> > >
> > > Kind Regards,
> > >
> > > Wouter Bijlsma,
> > > j.w.bijlsma@stud.tue.nl
> > >
> > >
> > > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > --
> > Ben Ricker <br...@wellinx.com>
> > Wellinx.com
> >
> >
> > ---------------------------------------------------------------------
> > 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
--
Ben Ricker <br...@wellinx.com>
Wellinx.com
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Re: Connection drops with tomcat-based game server (very short version)
Posted by Wouter Bijlsma <j....@stud.tue.nl>.
There's nothing in the logfiles (we are only using catalina.out) that would suggest that Tomcat even knows about a connection problem. The server just goes on as if nothing happened, but the messages it sends to the 'dead client' are never delivered. This might indeed be a load/config issue, although some users experienced the problem even when only 3 users were logged in. The confusing part is that we just cannot reproduce the bug on a fast network (not even with 15 users logged in), while neither the client nor the server use time-sensitive code for sending or receiving messages.
We are using tomcat 4.0.6 on a Debian/testing linux machine, kernel version 2.4.20
Wouter Bijlsma
On 21 Mar 2003 13:16:19 -0600
Ben Ricker <br...@wellinx.com> wrote:
> Sounds like a load issue coupled with a config issue. How about some
> logs entries? DO you see anything in the logs you setup? Catalina.out?
> Context log?
>
> Also, some idea what OS and version would also be helpful. It is nearly
> impossible to tell (at least for me).
>
> Ben Ricker
>
> On Fri, 2003-03-21 at 13:01, Wouter Bijlsma wrote:
> > Is it possible that tomcat sometimes randomly kills a request, does
> > not process a request or queues a request indefinitely, thereby
> > blocking a client that tries to read back the response to its request?
> > Could this be possible when a servlet communicates with the clients
> > using only raw data and InputStreams/OutputStreams? And: is it a good
> > idea to develop a game server for playing games like chess, chequers
> > or draughts with tomcat, considering the fact that tomcats main
> > purpose is to act as web application server using a strict
> > request-response paradigm. Is it safe to assume that every request
> > made by a client always yields a proper response, also when using raw
> > data transfers? Also when there's a really high volume of requests to
> > a single servlet?
> >
> > Don't get me wrong: I do *not* think there's something wrong with
> > tomcat! As a matter of fact I have really good experiences with it
> > using it for web applications!!
> >
> > Kind Regards,
> >
> > Wouter Bijlsma,
> > j.w.bijlsma@stud.tue.nl
> >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> --
> Ben Ricker <br...@wellinx.com>
> Wellinx.com
>
>
> ---------------------------------------------------------------------
> 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: Connection drops with tomcat-based game server (very short
version)
Posted by Ben Ricker <br...@wellinx.com>.
Sounds like a load issue coupled with a config issue. How about some
logs entries? DO you see anything in the logs you setup? Catalina.out?
Context log?
Also, some idea what OS and version would also be helpful. It is nearly
impossible to tell (at least for me).
Ben Ricker
On Fri, 2003-03-21 at 13:01, Wouter Bijlsma wrote:
> Is it possible that tomcat sometimes randomly kills a request, does not process a request or queues a request indefinitely, thereby blocking a client that tries to read back the response to its request? Could this be possible when a servlet communicates with the clients using only raw data and InputStreams/OutputStreams? And: is it a good idea to develop a game server for playing games like chess, chequers or draughts with tomcat, considering the fact that tomcats main purpose is to act as web application server using a strict request-response paradigm. Is it safe to assume that every request made by a client always yields a proper response, also when using raw data transfers? Also when there's a really high volume of requests to a single servlet?
>
> Don't get me wrong: I do *not* think there's something wrong with tomcat! As a matter of fact I have really good experiences with it using it for web applications!!
>
> Kind Regards,
>
> Wouter Bijlsma,
> j.w.bijlsma@stud.tue.nl
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
--
Ben Ricker <br...@wellinx.com>
Wellinx.com
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Re: Connection drops with tomcat-based game server (very short version)
Posted by Jake Robb <ja...@mac.com>.
This is an interesting proposition! I read both of your posts.
Personally, if I were you, I would create a custom server. David Flanagan's
Generic Multithreaded Server (as given in O'Reilly's Java Examples in a
Nutshell) would be a good starting point (if you're using it commercially,
there's a $50 license fee).
http://www.davidflanagan.com/javaexamples2/
I've never had Tomcat exhibit the request-killing behavior you describe. I
have also never used a GenericServlet, so that could possibly be the cause.
-Jake
----- Original Message -----
From: "Wouter Bijlsma" <j....@stud.tue.nl>
To: <to...@jakarta.apache.org>
Sent: Friday, March 21, 2003 2:01 PM
Subject: Connection drops with tomcat-based game server (very short version)
> Is it possible that tomcat sometimes randomly kills a request, does not
process a request or queues a request indefinitely, thereby blocking a
client that tries to read back the response to its request? Could this be
possible when a servlet communicates with the clients using only raw data
and InputStreams/OutputStreams? And: is it a good idea to develop a game
server for playing games like chess, chequers or draughts with tomcat,
considering the fact that tomcats main purpose is to act as web application
server using a strict request-response paradigm. Is it safe to assume that
every request made by a client always yields a proper response, also when
using raw data transfers? Also when there's a really high volume of requests
to a single servlet?
>
> Don't get me wrong: I do *not* think there's something wrong with tomcat!
As a matter of fact I have really good experiences with it using it for web
applications!!
>
> Kind Regards,
>
> Wouter Bijlsma,
> j.w.bijlsma@stud.tue.nl
>
>
> ---------------------------------------------------------------------
> 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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