From users-return-217744-apmail-tomcat-users-archive=tomcat.apache.org@tomcat.apache.org Thu Oct 07 22:18:15 2010 Return-Path: Delivered-To: apmail-tomcat-users-archive@www.apache.org Received: (qmail 97914 invoked from network); 7 Oct 2010 22:18:15 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 7 Oct 2010 22:18:15 -0000 Received: (qmail 38794 invoked by uid 500); 7 Oct 2010 22:18:12 -0000 Delivered-To: apmail-tomcat-users-archive@tomcat.apache.org Received: (qmail 38550 invoked by uid 500); 7 Oct 2010 22:18:12 -0000 Mailing-List: contact users-help@tomcat.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: "Tomcat Users List" Delivered-To: mailing list users@tomcat.apache.org Received: (qmail 38541 invoked by uid 99); 7 Oct 2010 22:18:12 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 07 Oct 2010 22:18:12 +0000 X-ASF-Spam-Status: No, hits=0.7 required=10.0 tests=RCVD_IN_DNSWL_NONE,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (nike.apache.org: local policy) Received: from [76.96.62.32] (HELO qmta03.westchester.pa.mail.comcast.net) (76.96.62.32) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 07 Oct 2010 22:18:03 +0000 Received: from omta20.westchester.pa.mail.comcast.net ([76.96.62.71]) by qmta03.westchester.pa.mail.comcast.net with comcast id FmRc1f0031YDfWL53yHjlK; Thu, 07 Oct 2010 22:17:43 +0000 Received: from [192.168.1.202] ([69.143.109.145]) by omta20.westchester.pa.mail.comcast.net with comcast id FyHj1f00538FjT13gyHj2e; Thu, 07 Oct 2010 22:17:43 +0000 Message-ID: <4CAE4705.5010000@christopherschultz.net> Date: Thu, 07 Oct 2010 18:17:41 -0400 From: Christopher Schultz User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.9) Gecko/20100915 Thunderbird/3.1.4 MIME-Version: 1.0 To: Tomcat Users List Subject: Re: Error 503 ocurring when server under load References: In-Reply-To: X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Virus-Checked: Checked by ClamAV on apache.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Rob, On 10/7/2010 12:59 PM, Rob G wrote: > Recently migrated a production site (mixture of Servlets and JSPs) > from Oracle Application Server to Apache/Tomcat. Since then we have > seen numerous HTTP Error 503 - Service unavailable errors at peak > times when site is under load. mod_jk.log has the following error > message(s): > > [2184:1952] [error] jk_lb_worker.c (1473): All tomcat instances > failed, no more workers left Just to reinforce a comment by Andre, I think you might want to compare the request processor counts you have for Tomcat versus mod_jk: the default maxThreads for a Tomcat is 200, while your MaxClients settings might be different on your Apache httpd configuration. If you have httpd.MaxClients=250 and connector.maxThreads=200 then you have a deficit of 50 who will get 503 errors if they try to access your webapp during peak load. > Apache: 2.2.16 I believe that only the Worker MPM is available on Microsoft Windows. Have you explicitly configured an MPM? > worker.worker1.cachesize=10 You might want to read the documentation for worker.cachesize in http://tomcat.apache.org/connectors-doc/reference/workers.html Note that it's deprecated and you should use connection_pool_size instead. Since you're using Apache 2.x, mod_jk should be able to auto-configure this value for you. - From my reading, you may be limiting yourself to 10 simultaneous connections from Apache httpd to Tomcat, and others will get a 503. Rainer or Mladen will have to comment to clarify: I am certainly no expert in mod_jk configurations. Hope that helps, - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyuRwUACgkQ9CaO5/Lv0PC3nACePwYgc2w4td8jSdRCM5rp9IB9 PB4AoKj4cR9F+FhsR20W4vIvcWkRevyL =nuW/ -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org For additional commands, e-mail: users-help@tomcat.apache.org