I am using Tomcat 3.2.1, Apache 1.3.14, running on
Solaris 2.8, Sun machines.
After various attempts of debugging this, I have
more information.
1. Even though I'm setting the worker's property
cache_size to default (1), I'm finding there
are up to 6 connections opened from Apache to
Tomcat. I deduce this by looking at the mod_jk.conf
and by doing netstat.
I finally find out, this is so because my Apache
is set to spawn minimum of 6 children and each
of those children are making separate connections
to Tomcat.
This is very bad because, I ended up having to
reload 6 times before Tomcat starts serving me
the page again. Each time it uses a different
Apache children that has defunct socket. So the
more Apache children I have, the longer it takes
me to recover from this problem.
2. It seems when Tomcat dies & restarts, the send()
called by ajp13's jk_tcp_socket_sendfull() does not
get an error. But the recv() does get an error, with
errno ECONNRESET. After which, the socket is properly
closed.
3. When I shutdown Tomcat, those sockets that were
opened between Apache/Tomcat showed up in state
CLOSE_WAIT, and FIN_WAIT2. I think this is normally
solved by calling the shutdown() API after closing
the socket. However, this would have to be done from
the Tomcat side in Ajp13ConnectionHandler.java.
I can't find the corresponding method of Socket
in Java.
So.. based on all of these, the only fix I can think
of putting is to make mod_jk retry the send() if
recv() comes back with an error ECONNRESET. The retry
should happen after the old socket is properly closed.
Anyone wants to comment?
shinta
> -----Original Message-----
> From: Dan Milstein [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, March 06, 2001 12:00 PM
> To: [EMAIL PROTECTED]
> Subject: Re: FW: problem w/ ajp13 - if Tomcat is shutdown
>
>
> What version of TC are you using? What version of Apache?
>
> I would look into the mod_jk docs -- I think this is the
> spec'd behavior
> (which, admittedly, is not great, but that makes it more of a feature
> request than a bug ;-). With ajp13, Apache opens up a
> persistent TCP/IP
> connection TC -- if TC restarts, I think that connection may
> just hang up
> and then timeout (since Apache doesn't know that TC has restarted).
>
> If anyone wants to work on this, you would have the undying
> thanks of the
> rest of the TC community -- having to restart Apache all the
> time bugs a
> *lot* of people.
>
> -Dan
>
> > Shinta Tjio wrote:
> >
> > I'm having problem with mod_jk if ajp13 is used.
> >
> > The problem is often reproduced when Tomcat is shut
> > down without Apache being shut down. When a request
> > is fired through Apache as soon as Tomcat starts,
> > I often get Internal Server Error. The mod_jk.log
> > will have the following:
> >
> > > [jk_uri_worker_map.c (344)]: Into
> jk_uri_worker_map_t::map_uri_to_worker
> >
> > > [jk_uri_worker_map.c (406)]:
> jk_uri_worker_map_t::map_uri_to_worker,
> > > Found a match ajp13
> > > [jk_worker.c (123)]: Into wc_get_worker_for_name ajp13
> > > [jk_worker.c (127)]: wc_get_worker_for_name, done found a worker
> > > [jk_ajp13_worker.c (651)]: Into jk_worker_t::get_endpoint
> > > [jk_ajp13_worker.c (536)]: Into jk_endpoint_t::service
> > > [jk_ajp13.c (346)]: Into ajp13_marshal_into_msgb
> > > [jk_ajp13.c (480)]: ajp13_marshal_into_msgb - Done
> > > [jk_ajp13_worker.c (203)]: connection_tcp_get_message: Error -
> > > jk_tcp_socket_recvfull failed
> > > [jk_ajp13_worker.c (619)]: Error reading request
> > > [jk_ajp13_worker.c (489)]: Into jk_endpoint_t::done
> >
> > If I hit reload multiple times, eventually Tomcat will
> > serve the servlet fine.
> >
> > Did anyone see this problem before? Is there anyway
> > around this?
> >
> > shinta
>
> --
>
> Dan Milstein // [EMAIL PROTECTED]
>
