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From <>
Subject RE: [users@httpd] Load balancing question
Date Mon, 17 Sep 2007 13:23:51 GMT
Hi James
Try adding the following line to your mod_jk config for more verbose
JkRequestLogFormat "%w %V %U %s %T %B %H %m"
It can be a few things that cause the errors you are getting. I would
suggest reading the timout howto on mod_jk to set a few settings:
Other than that try restarting the tomcats.


	From: James Sherwood [] 
	Sent: 17 September 2007 13:13
	Subject: Re: [users@httpd] Load balancing question
	I cannot get my mod_jk status page to work.  Maybe it is because
I am on windows?
	It seems:
	only takes a linux style path for the mount?
	We upgraded to the latest mod_jk and this were the results:
	1: All monitors were fine, there were no bottlenecks anywhere
that we could find(cpu's,HD's and networks all seemed fine).
	2: This time when we brought the servers to their knees, they
recovered a short time after the test was completed.
	3: We tried the socket_keepalive=true for the workers and the
server did not recover after
	4: the only problem we can find is after the test in the mod_jk
log we have about 20-30 lines of this:
	[Mon Sep 17 08:03:49.906 2007] [7948:4868] [error]
jk_ajp_common.c (2097): (tomcat5) Connecting to tomcat failed. Tomcat is
probably not started or is listening on the wrong port
	The lines vary only by the (tomcat5) being any of the tomcats in
the loadbalance.
	It seems like apache/tomcat/mod_jk are reaching the max number
of connections between each other or something?
	Any help would be GREATLY appreciated,

		----- Original Message ----- 
		From: Bj <>  
		Sent: Saturday, September 15, 2007 5:17 AM
		Subject: Re: [users@httpd] Load balancing question

		What says your mod_jk status page ? 
		try to monitor during the load to see if your workers
are in error or OK state, il the max busy is reached,....
		Then look at your logs (mod_jk, apache, tomcat, webapps
logs, windows,...) 
		As said before, you should check the number of tcp
connections opened. If your do not use keep alive feature you can have a
bootleneck there (apache and tomcat servers).You can also have error
like max opened file reached. 
		Then look at the load average,system cpu, iowait,..
		You can also monitor your tomcats through JMX (using
jconsole or missioncontrol) to check that garbage collections works fine
and just don't hang up too long. 
		try to deactivate the 2 tomcat instances on your apache
server to see if httpd is still available after the load test.
		On 9/14/07, James Sherwood <>

			Everything is Windows2003 Server.
			After the load we cannot load pages either
through apache or by contacting
			tomcat directly.
			I beleive you are on the right path tho, about
connections not getting 
			released, thats what I figure it is too but I do
not know how to fix it.
			----- Original Message -----
			From: "AFrieze" < >
			To: <>
			Sent: Friday, September 14, 2007 12:02 PM
			Subject: Re: [users@httpd] Load balancing
			>> We also have the problem of once the load
stops, the sites are still down
			>> but Apache/tomcats still seem to be running
fine.  A restart of
			>> either(not even both) fixes the sites.
			> A guess 
			>  Your apache server is not releasing
connections.  If you are running
			> linux, type  "netstat -vat" into a terminal on
your apache machine, before
			> and after you hit your server.  See if the
connections are being released. 
			> You could also try typing "ps -e | grep
"httpd"" to see how many apache
			> processes are being run before/after.  Look in
the apache error log, etc.
			> You might find a clue like "MaxClients
			> Question
			> Are you able to log into all your
tomcats(through port 8080) independent
			> of apache and get served requests?  Can you
log onto apache and get a
			> statically served page?
			> Cheers
			> AFrieze
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