On 11/19/2014 09:27 PM, Lisa Woodring wrote:
Actually, I received a little clarification on the monitoring software
(I didn't write it). What it's trying to test is that the AJP port
itself is actually accepting connections. With Apache in front in a
production system, it could forward the actual request to one of
several Tomcat boxes -- but we don't know which one from the outside.
The monitoring software is trying to test -- for each Tomcat instance
-- if it is accepting connections. It used to send an "nmap" request,
but now sends essentially a "tcp ping" -- gets a response & moves on.
In my case (homemade monitoring) i choosed to check mod_jk's log, after all
mod_jk does indeed check the state of the ajp connector in tomcat.
Hope this helps.
[... ]
Thanks for the idea. Can you tell me what you specifically look for
in the "mod_jk_log" file? Do you look for the presence of something?
or the absence of something?
grep out cping,
I only see 'negative' events in the logfile. For example,
"all endpoints are disconnected, detected by connect check(1),
cping(0), send(0)"
which evidently, is when Tomcat releases a connection on its end.
(I set JkLogLevel = DEBUG, but still don't see any messages that look
like what I would want...)
Just ignore the cping part. I categorize the failure modes in two,
client error (user closes the browser window or is slow), example:
[Thu Nov 20 10:19:36 2014] [29858:1626331456] [info]
service::jk_lb_worker.c (1388): service failed, worker p3 is in local
error state
[Thu Nov 20 10:19:36 2014] [29858:1626331456] [info]
service::jk_lb_worker.c (1407): unrecoverable error 200, request failed.
Client failed in the middle of request, we can't recover to another
instance.
[Thu Nov 20 10:19:36 2014] [29858:1626331456] [info]
jk_handler::mod_jk.c (2611): Aborting connection for worker=worker_p
Or server error, can be because of timeout (backend too busy):
[Thu Nov 20 10:19:54 2014] [31475:1317062976] [error]
ajp_get_reply::jk_ajp_common.c (2020): (p7) Timeout with waiting reply
from tomcat. Tomcat is down, stopped or network problems (errno=110)
[Thu Nov 20 10:19:54 2014] [31475:1317062976] [info]
ajp_service::jk_ajp_common.c (2540): (p7) sending request to tomcat
failed (recoverable), because of reply timeout (attempt=1)
[Thu Nov 20 10:19:54 2014] [31475:1317062976] [error]
ajp_service::jk_ajp_common.c (2559): (p7) connecting to tomcat failed.
Another server error is connection refused, when the backend is extra
busy (on linux net.ipv4.tcp_max_syn_backlog sockets waiting on the tcp
stack) or tomcat is down. I dont have an example of this right now though
Anyway, this way you use mod_jk's logic instead of having to create an
ad hoc one. This is at JkLogLevel notice, no need to enable debug.
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org
