Have you counted the actual # of requests for both apaches via something like server-status, or looked in mod_jk.log, that they are both receiving an equal # of successful requests? The "Writing to client aborted or client network problems" are nothing to really worry about. They usually mean the browser/client has closed the connection (clicked Stop or clicked Back) before the request was done being processed/sent.
-Tony --------------------------- Manager, IT Operations Format Dynamics, Inc. 303-573-1800x27 abia...@formatdynamics.com http://www.formatdynamics.com -----Original Message----- From: Ian Long [mailto:ian.l...@opterus.com] Sent: Thursday, March 05, 2009 10:57 AM To: users@tomcat.apache.org Subject: Tomcat and Apache with mod_jk Hi, I have dedicated RHEL5 boxes (dedicate quad core, 4GB RAM) setup with both apache httpd and tomcat running on the same box, with a hardware load balancer selecting the node a user is routed to. I have mod_jk setup, but am seeing some behaviour I'm not sure is correct. This is on httpd 2.2.3, tomcat 6.0.16, and mod_lk version of 1.2.26. The load balancer pings the machines every 2 seconds as part of a health check. Below are the relevant bits of my configuration: mod_jk.conf ========== LoadModule jk_module modules/mod_jk.so JkLogFile /var/log/httpd/mod_jk.log JkLogLevel info JkWorkersFile /etc/httpd/conf.d/workers.properties JkShmFile /var/log/httpd/jk.shm JkShmSize 800 JkOptions +ForwardURICompatUnparsed JkMount /* ajp13 JkUnMount /cacti/* ajp13 JkUnMount /manager/* ajp13 workers.properties ============== worker.list=ajp13 worker.ajp13.port=8009 worker.ajp13.host=localhost worker.ajp13.maintain=60 worker.ajp13.type=ajp13 # worker.ajp13.connection_pool_minsize=0 worker.ajp13.connection_pool_timeout=600 worker.ajp13.connect_timeout=10000 worker.ajp13.prepost_timeout=10000 worker.ajp13.max_packet_size=16384 httpd.conf ======== <IfModule prefork.c> StartServers 8 MinSpareServers 5 MaxSpareServers 20 ServerLimit 800 MaxClients 800 MaxRequestsPerChild 0 </IfModule> server.xml ======== <Connector port="8009" connectionTimeout="600000" minSpareThreads="5" packetSize="16384" address="127.0.0.1" enableLookups="false" disableUploadTimeout="true" maxSpareThreads="75" maxThreads="800" protocol="AJP/1.3" /> On one machine, after 5 or 6 hours, when I run netstat to look at connections between http and tomcat, I have 250 or so: tcp 0 0 ::ffff:127.0.0.1:8009 ::ffff: 127.0.0.1:60408 ESTABLISHED whereas the other machine only has 40 or so, and they are equally load balanced. I tried setting worker.ajp13.connection_pool_minsize=0 but this has no effect on what I'm seeing. Is this the behaviour I should expect? The load on the machine is not that heavy, at the busiest period there would be 3 request per second going to the box. I wouldn't expect this number to keep growing, especially under light load. I'm also seeing a few errors like the following in mod_jk.log: [Thu Mar 05 10:34:08.878 2009] [25849:3086382864] [info] ajp_process_callback::jk_ajp_common.c (1603): Writing to client aborted or client network problems [Thu Mar 05 10:34:08.878 2009] [25849:3086382864] [info] ajp_service::jk_ajp_common.c (2186): (ajp13) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1) [Thu Mar 05 10:34:08.878 2009] [25849:3086382864] [info] jk_handler::mod_jk.c (2357): Aborting connection for worker=ajp13 [Thu Mar 05 10:34:28.527 2009] [26222:3086382864] [info] ajp_process_callback::jk_ajp_common.c (1603): Writing to client aborted or client network problems [Thu Mar 05 10:34:28.527 2009] [26222:3086382864] [info] ajp_service::jk_ajp_common.c (2186): (ajp13) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1) [Thu Mar 05 10:34:28.528 2009] [26222:3086382864] [info] jk_handler::mod_jk.c (2357): Aborting connection for worker=ajp13 [Thu Mar 05 10:36:01.071 2009] [25855:3086382864] [info] ajp_process_callback::jk_ajp_common.c (1603): Writing to client aborted or client network problems [Thu Mar 05 10:36:01.072 2009] [25855:3086382864] [info] ajp_service::jk_ajp_common.c (2186): (ajp13) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1) [Thu Mar 05 10:36:01.072 2009] [25855:3086382864] [info] jk_handler::mod_jk.c (2357): Aborting connection for worker=ajp13 [Thu Mar 05 11:53:42.298 2009] [27523:3086382864] [info] ajp_process_callback::jk_ajp_common.c (1603): Writing to client aborted or client network problems [Thu Mar 05 11:53:42.298 2009] [27523:3086382864] [info] ajp_service::jk_ajp_common.c (2186): (ajp13) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1) [Thu Mar 05 11:53:42.298 2009] [27523:3086382864] [info] jk_handler::mod_jk.c (2357): Aborting connection for worker=ajp13 [Thu Mar 05 12:08:07.551 2009] [28365:3086382864] [info] ajp_process_callback::jk_ajp_common.c (1603): Writing to client aborted or client network problems [Thu Mar 05 12:08:07.551 2009] [28365:3086382864] [info] ajp_service::jk_ajp_common.c (2186): (ajp13) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1) [Thu Mar 05 12:08:07.551 2009] [28365:3086382864] [info] jk_handler::mod_jk.c (2357): Aborting connection for worker=ajp13 [Thu Mar 05 12:08:17.432 2009] [28428:3086382864] [info] ajp_process_callback::jk_ajp_common.c (1603): Writing to client aborted or client network problems [Thu Mar 05 12:08:17.432 2009] [28428:3086382864] [info] ajp_service::jk_ajp_common.c (2186): (ajp13) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1) [Thu Mar 05 12:08:17.433 2009] [28428:3086382864] [info] jk_handler::mod_jk.c (2357): Aborting connection for worker=ajp13 [Thu Mar 05 12:12:19.656 2009] [28363:3086382864] [info] ajp_process_callback::jk_ajp_common.c (1603): Writing to client aborted or client network problems [Thu Mar 05 12:12:19.656 2009] [28363:3086382864] [info] ajp_service::jk_ajp_common.c (2186): (ajp13) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1) [Thu Mar 05 12:12:19.657 2009] [28363:3086382864] [info] jk_handler::mod_jk.c (2357): Aborting connection for worker=ajp13 Can anyone see anything wrong with the configuration? Cheers, Ian Long Chief Software Architect, Opterus Inc. Email: ian.l...@opterus.com Phone: 416-840-8495 x666 Mobile: 416-817-9206 Web: http://www.opterus.com --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
