> -----Original Message----- > From: kharp...@oreillyauto.com [mailto:kharp...@oreillyauto.com] > Sent: Thursday, January 03, 2013 8:31 AM > To: users@tomcat.apache.org > Subject: Limiting threads per context > > > Hello All, > > Yesterday we had a Tomcat6 server reach maxThreads and stay that way > until we restarted it. After researching a thread dump and some log > files, we found one of the applications is creating > NullPointerExceptions and subsequently leaving a TP-ProcessorX in > WAITING state indefinitely for a DB closePreparedStatement return. As > more requests come in for this application threads are being > established and put into BLOCKED state, waiting on TP-ProcessorX. > Eventually, the server hits maxThreads and stops serving requests > almost entirely. > > Obviously the application causing this needs to (and is being) fixed. > But I'm curious if there is a higher level of protection that could be > implemented to help protect the other applications (contexts) on this > server? For example, is there a way to specify that a context can only > use X number of request threads? Or perhaps X number of threads from > an executor? Et cetera. > > I haven't seen anything in the docs that would do this, but it never > hurts to ask. Here's our server info in case it's helpful: > OS: Ubuntu 12.04 64-bit > Front-end Server: Apache 2.2.22 (mod_ajp to back-end via Balancer > setup) Back-end App Server: Tomcat 6.0.24 (AJP & HTTP connectors, no > executor) Java -version output: > java version "1.6.0_20" > OpenJDK Runtime Environment (IcedTea6 1.9.13) > (6b20-1.9.13-0ubuntu1~10.04.1) > OpenJDK 64-Bit Server VM (build 19.0-b09, mixed mode) > > > Thanks, > Kyle Harper >
Kyle - Processor threads are tied to connectors, either directly or via executors. Therefore, if these are all contexts under one host, or you are sharing the connector (IP/port pair) for multiple hosts, I don't think there is anything you can do. However, since you are front-ending with apache, you might be able to set up multiple connectors (IP/port pair) on the Tomcat server and use the front end to direct each context to a different connector. In this case, you can probably ignore setting up the executors, since you are not going to be sharing threads between the contexts. Jeff --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
