-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 DAvid,
On 11/22/11 3:57 PM, David Dabbs wrote: > We're going to be upgrading some vintage version 6 Tomcats to TC 7. > > > I was wondering if there's any migration guide, in particular any > discussion of the advantages to using thread pools/executors. So, you already have two responses about reading the documentation :( In terms of actually using Executors, I wound say that you definitely want to use one (or more). Here are a couple of reasons: 1. You can unify all request processor threads under one roof: the executor can be shared among connectors, so you have a single pool of threads for servicing requests instead of having to have several pools, all of which have a large number of threads "just in case". 2. Executor thread pools can reduce the number of active threads when traffic is low. This will free-up memory on the server during slow times and make the server (slightly) more responsive as well. There really doesn't seem to be a reason not to use an Executor. Note: if you are making loopback-requests (that is, a thread makes an HTTP (or other) connection back to Tomcat itself for some reason like an HTTP include, etc.) then you might want to make sure that you use a separate pool for the loopback requests. Depending on the volume of these requests, you can deadlock your server if you're not careful: if you get N requests that trigger a loopback request, you'll get N loopback requests for a total requirement of 2*N request processors. It's conceivable that, if you have N request processors, N requests will arrive and trigger N loopback requests, none of which can be accepted because the original N request processors are stuck waiting on the loopback requests. Eventually, everything should time-out, but you can get yourself a few minutes of lock-up if you're not careful. To be sure, that's a contrived scenario and would "never happen"... until it happens to your server under load and someone says "wow, we never thought that would happen". - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk7MF6QACgkQ9CaO5/Lv0PBhdQCdEjNC/lvDKqpmZqejniHCfw3h vmAAoKJ+IGOYag5M+/q3OjhI+cLgeunh =5cjn -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
