Hi Christopher, And thank you for this invaluable information !
I shall continue the discussion if the problem persists after the update of my configuration. Nicolas SARAZIN 2012/9/21 Christopher Schultz <ch...@christopherschultz.net>: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Nicholas, > > On 9/21/12 4:14 AM, Nicolas Sarazin wrote: >> Ok for all versions upgrades, I put it in my todo list ! It is a >> customer environment, I can't make it immediately. > > That's okay, but you need to be ready when your customer says "hey, > Tomcat 5.5.x is no longer supported: we need to upgrade". > >>> Christopher Schultz wrote: >>> >>> Do you have anything else? If not, why bother with Apache httpd? >> >> Yes, we have lot of directives (using mod_cache, mod_proxy, ...). >> In reality, I have about twenty VirtualHost. > > Fair enough: it's always worth asking. Lots of people think that > Apache httpd is, for some reason, required. > >>> What MPM are you using? If you are using prefork, then your >>> connection_pool_size is all wrong. Generally speaking, you >>> should allow mod_jk to determine its own value for >>> connection_pool_size when using Apache httpd. >>> >>> How many backend Tomcat servers do you have? Looks like one. >>> >>> Let's assume you are using threaded MPM in httpd (otherwise the >>> value for 1200 is insane) and you are using only one backend >>> Tomcat server. >>> >>> You have 1200 connections configured in httpd >>> (connection_pool_size), but Tomcat can only accept 600 of them >>> (maxThreads) at any given time. You have used backlog=8192 to >>> cover this up so things become even more confusing. >> >> I using prefork. Indeed, in Apache documentation : "Do not use >> connection_pool_size with values higher then 1 on Apache 2.x >> prefork or Apache 1.3.x!". It's better to delete it or to put its >> value to 1 ? > > I would delete the option altogether - per the documentation - and > allow mod_jk to select the appropriate setting. > >> What problems can arise with mpm prefork and connection_pool_size > >> 1 ? > > A big waste of memory and a lot of needless overhead. I dunno how > mod_jk manages its connections, but it might immediately open 1200 > connections per prefork process to your backend, which can waste a lot > of resources, too. > >>>> Usually, it's work correctly, but sometime, only on certain >>>> pages, woker can't connect to Tomcat. In my logs files, I have >>>> : >>> >>> I think it's only a coincidence that /page2 consistently gives >>> you 500-response errors, here. Try looking at a wider section of >>> your httpd access log to determine if there really is something >>> special about /page2 (of course, /page2 could be returning >>> 500-response itself: you might want to check on that). >> >> This page was in error 500 in acces log between 19:12:27 and >> 20:04:39. >> >>>> How can we explain this behavior ? >>> >>> There are lots of explanations for what you are seeing. >>> >>> A few questions: >>> >>> 1. Do you really need Apache httpd at all? 2. Can you configure >>> cping/cpong for connection liveness testing? 3. Have you tried >>> disabling AJP connection re-use altogether? localhost >>> communication is fast fast fast. >> >> 1 - Yes :) 2 - Yes, but not immediately 3 - I don't, but I am going >> to test ! > > Good luck. > > - -chris > -----BEGIN PGP SIGNATURE----- > Version: GnuPG/MacGPG2 v2.0.17 (Darwin) > Comment: GPGTools - http://gpgtools.org > Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ > > iEYEARECAAYFAlBc4BMACgkQ9CaO5/Lv0PA/8gCgm0FxMnBA7t5lxZzB5t5rZMPg > tAkAniqoOQWd7ttK+COk9w0I1g9HHt6R > =59/Q > -----END PGP SIGNATURE----- > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
