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Post new topic   Forum Index -> Third-party Modules View previous topic :: View next topic
Reply to topic   Topic: mod_jk - tomcat randomly no response
Author
Qmpeltaty



Joined: 06 Feb 2008
Posts: 182
Location: Poland

PostPosted: Wed 19 Oct '11 11:50    Post subject: mod_jk - tomcat randomly no response Reply with quote

Hello

I'm experiencing random communication problems between Apache module mod_jk and Tomcat 6.0 bundled with JBoss application server.

Problem occurs only due heavy traffic but i belive that this machine can handle x100 more requests and the power of machine is not a problem - see below.
I'm also experiencing increasing response time in mod_jk logs for this time - from <1s to 4-10sec. for processed requests, where others are not processed at all.

mod_jk log :

Code:

[00:48:35]loadbalancer 2.012404
[00:48:35][10716:19332] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028004
[00:48:35]loadbalancer 2.043604
[00:48:35][10716:4016] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028004
[00:48:35][10716:20800] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028004
[00:48:35][10716:3696] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:17020] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.043604
[00:48:35]loadbalancer 2.012403
[00:48:35][10716:16372] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028003
[00:48:35][10716:3836] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:1752] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:17828] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.043603
[00:48:35]loadbalancer 2.028003
[00:48:35]loadbalancer 2.028003
[00:48:35][10716:15000] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.012403
[00:48:35][10716:2724] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:14144] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:5396] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:5332] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028003
[00:48:35]loadbalancer 2.090404
[00:48:35][10716:6180] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028003
[00:48:35][10716:3344] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:20596] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.012403
[00:48:35][10716:20668] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028003
[00:48:35]loadbalancer 2.012403
[00:48:35]loadbalancer 2.012403
[00:48:35]loadbalancer 2.028003
[00:48:35][10716:4132] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:14968] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028003
[00:48:35][10716:12200] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:12572] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.028003
[00:48:35][10716:2904] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35][10716:5380] [error] jk_ajp_common.c (2097): (node1) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[00:48:35]loadbalancer 2.012403
[00:48:35]loadbalancer 2.028003
[00:48:35]loadbalancer 2.012403
[00:48:35]loadbalancer 2.028003
[00:48:35]loadbalancer 6.739212
[00:48:35]loadbalancer 7.191612


As there is no further problems registered in logs on JBoss side i suspect that only communication problem exist (as Tomcat is responsible for communication on behalf of JBoss). I suspect that it could be misconfiguration problem as well - config details listed below.

mod_jk.conf

Code:


# Define list of workers that will be used
# for mapping requests
# The configuration directives are valid
# for the mod_jk version 1.2.18 and later
#
worker.list=loadbalancer,status

# Define Node1
# modify the host as your host IP or DNS name.
worker.node1.port=8009
worker.node1.host=127.0.0.1
worker.node1.type=ajp13
worker.node1.max_packet_size=65536
worker.node1.lbfactor=1

#The next three properties allow mod_jk to efficiently determine if a connection is in error or not responding fast enough due to whatever reason.
worker.node1.connect_timeout=15000
worker.node1.socket_timeout=60
#This value must equal server.xml's connectionTimeout of 1 minutes
worker.node1.connection_pool_timeout=60
worker.node1.socket_keepalive=True
# worker.node1.connection_pool_size=10 (1)

# Load-balancing behaviour
worker.loadbalancer.type=lb
worker.loadbalancer.balance_workers=node1
worker.loadbalancer.sticky_session=1

# Status worker for managing load balancer
worker.status.type=status



server.xml (8009 connnector)

Code:

<!-- A AJP 1.3 Connector on port 8009 -->
         <Connector port="8009" maxPostSize="6291456" address="${jboss.bind.address}" connectionTimeout="60000" protocol="AJP/1.3"
         emptySessionPath="true" enableLookups="false" maxThreads="2500" redirectPort="8443" packetSize="65536" />



Both services works on the same machine - IBM with 8 x Xeon E7-4870 (80 cores in total), 64GB RAM, RAID 10.
Machine handle Apache 2.2.21 with mod_jk 1.2.25 , JBoss 6.0 and PostgreSQL 9.0.4 on Win2k8 x64 R2 Enterprise.

How to solve it ??
Back to top
James Blond
Moderator


Joined: 19 Jan 2006
Posts: 7373
Location: Germany, Next to Hamburg

PostPosted: Tue 25 Oct '11 11:19    Post subject: Reply with quote

Sometimes clustering jboss even on the same machine makes sence and than putting apache as reverse balancer before it. So you might run 2 or 3 instances on the same server or on different servers.

If you still have a question please ask again.
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