Hi, We are running apache 2.2.4 and tomcat 5.5.28 with mod_jk 1.2.28. 3 tomcat instances.
Referring to http://tomcat.apache.org/connectors-doc/reference/workers.html , we came up with a workers.properties file like this: worker.list=balancer worker.maintain=30 #tomcat01 worker.tomcat01.port=18009 worker.tomcat01.host=localhost worker.tomcat01.type=ajp13 worker.tomcat01.lbfactor=120 worker.tomcat01.retries=2 worker.tomcat01.socket_timeout=30 worker.tomcat01.reply_timeout=30000 worker.tomcat01.recover_time=300 #tomcat02 worker.tomcat02.port=28009 worker.tomcat02.host=localhost worker.tomcat02.type=ajp13 worker.tomcat02.lbfactor=100 worker.tomcat02.retries=2 worker.tomcat02.socket_timeout=30 worker.tomcat02.reply_timeout=30000 worker.tomcat02.recover_time=300 #tomcat03 worker.tomcat03.port=38009 worker.tomcat03.host=localhost worker.tomcat03.type=ajp13 worker.tomcat03.lbfactor=0 worker.tomcat03.retries=2 #loadbalancer worker.retries=2 worker.balancer.type=lb worker.balancer.sticky_session=False worker.balancer.method=Busyness worker.balancer.balance_workers=tomcat01,tomcat02,tomcat03 So basically tomcat01 and tomcat02 are the main request handlers, with tomcat03 acting as a backup server which is accessed only when both tomcat01 and tomcat02 are in error state (30 seconds without response, not necessarily mean offline). If something bad happens, e.g. excessively long GC, or redeployment, we assume each failed tomcat instance to get back to business in about 5 minutes. This meets our needs to a certain degree. However, there's one thing that bugs me: If we set the reply_timeout too high, we miss the whole point of fail-over. If we set the value too low, it's likely we are going to kill a lot of legitimate/would-otherwise-success request, which is not what we wanted either. Instead of breaking the long request (say, >30 seconds) and put the worker into "error" state, is there anyway, anyway at all, we can tell mod_jk to mark a worker "busy", so that future requests are routed to alternative workers? mok_jk can still check every 30 (or the default 60) seconds whether it is able to resume one of the "busy"-marked workers, just like it does with the ones in "error" state. Regards, Sean --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
