Thanks Chris for the response. -Venky
-----Original Message----- From: Christopher Schultz [mailto:[EMAIL PROTECTED] Sent: Monday, October 22, 2007 1:04 PM To: Tomcat Users List Subject: Re: Number of Threads in request processing pool and JVM heap size -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Venky, Venkatesh Jayaraman (jvenky) wrote: > I have 80 servlets on tomcat and each of them can have 5 five concurrent > requests to be processed as per design. That is an odd design. Why up to five, but no more? > 80 * 5 = 400 thread I need for on the connector? ( So I can set > this to maxThreads = 400) These settings have more to do with what your hardware can handle than what your software specification is. Don't forget that if you allow 400 concurrent connections, they might /all/ go to the same servlet. If you really allow only 5 concurrent connections to a single servlet (weird?!), then you might end up with lots of stalled threads (potentially 395 of them) waiting for those 5 magic slots. > Each thread needs 2 MB per thread then Is that an observation, or a guess? > JVM heap size max = 400 * 2 MB (1GB) + 20 % buffer = > 1GB I think you mean 800MB + 20% buffer ~= 1GB. Don't forget that there is some non-thread-related overhead, like session data (you might not have any), any shared caches you might have, and the weight of Tomcat itself. > Does this seems a better assumptions for designing web server using > tomcat? What you really need to do is load testing. Set up a test where you have 100 threads exercising your system and watch the memory usage. Bump it up to 200 and observe again. You can't do this just with guesses and mathematics: at some point, you have to actually try it. You might find that you can't reliably support 400 connections on a single machine. You may also find out that your memory requirements are lighter than you expected. You may also find that you don't really /need/ 400 simultaneous connections, and that 250 is fine, even if you'd like to support more. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHHQJC9CaO5/Lv0PARAqIvAKC2HV8RcyN294EqeW8RBRM3w3RWVgCfVs2t wx0Pdazmj5vBPLw5Tt4M9NE= =n02p -----END PGP SIGNATURE----- --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
