>-----Original Message----- >From: Igor Cicimov [mailto:icici...@gmail.com] >Sent: Wednesday, July 25, 2012 9:12 PM >To: Tomcat Users List >Subject: Re: Intermittent mod_proxy_ajp error - APR does not understand this >error code: proxy: dialog > >You have max clients on the apache side set to 400 but only 300 threads on >tomcat side. No wonder you get 500 error...
Thanks for the suggestion Igor, I increased the tomcat threads to 400 but that did not resolve the issue. Tony > >On Wed, Jul 25, 2012 at 12:22 AM, Carlucci, Tony <acarlu...@mitre.org>wrote: > >> Cross-posting this to the tomcat users list (also posted to users@httpd >> )... >> >> Hello, I've been trying to track down an intermittent problem with a Java >> web application that is running on tcServer fronted by Apache HTTP Server. >> We get intermittent "Server Unavailable / HTTP 500" errors, and when we >> do see them, there is the same set of log statements written to the Apache >> HTTP Server error log: >> >> [Mon Jul 23 10:03:15 2012] [error] (70014)End of file found: >> ajp_ilink_receive() can't receive header >> [Mon Jul 23 10:03:15 2012] [error] ajp_read_header: ajp_ilink_receive >> failed >> [Mon Jul 23 10:03:15 2012] [error] (120006)APR does not understand this >> error code: proxy: dialog to 127.0.0.1:7071 (127.0.0.1) failed >> >> We are not seeing any error messages in the tcServer logs. >> >> I believe the issue is with the mod_proxy_ajp module but it's been very >> difficult tracking down what exactly the problem is. What's interesting >> is that this Apache / tcServer configuration is used with other >> applications that work just fine and never have the intermittent 500 error. >> We also can run our application strictly in Tomcat (no Apache front) >> without any intermittent errors. >> >> We haven't ruled out that there could be something in our Java application >> code that is causing this, in combination with the mod_proxy_ajp module, >> but we have hit a wall as to what this issue could be. Has anyone else >> experienced a similar intermittent issue combined with the above error >> messages? Below is a copy of the error log and some configuration settings. >> >> Thanks, Tony >> >> --------------------- >> Apache HTTP Error Log >> --------------------- >> [Mon Jul 23 10:03:15 2012] [debug] mod_cache.c(141): Adding CACHE_SAVE >> filter for /myapp/ >> [Mon Jul 23 10:03:15 2012] [debug] mod_cache.c(148): Adding >> CACHE_REMOVE_URL filter for /myapp/ >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(45): proxy: AJP: >> canonicalising URL //127.0.0.1:7071/myapp/ >> [Mon Jul 23 10:03:15 2012] [debug] proxy_util.c(1506): [client >> ***cleansed***] proxy: ajp: found worker ajp://127.0.0.1:7071/myapp for >> ajp://127.0.0.1:7071/myapp/ >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy.c(1020): Running scheme ajp >> handler (attempt 0) >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_http.c(1963): proxy: HTTP: >> declining URL ajp://127.0.0.1:7071/myapp/ >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(681): proxy: AJP: >> serving URL ajp://127.0.0.1:7071/myapp/ >> [Mon Jul 23 10:03:15 2012] [debug] proxy_util.c(2011): proxy: AJP: has >> acquired connection for (127.0.0.1) >> [Mon Jul 23 10:03:15 2012] [debug] proxy_util.c(2067): proxy: connecting >> ajp://127.0.0.1:7071/myapp/ to 127.0.0.1:7071 >> [Mon Jul 23 10:03:15 2012] [debug] proxy_util.c(2193): proxy: connected >> /myapp/ to 127.0.0.1:7071 >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(224): Into >> ajp_marshal_into_msgb >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[0] [x-forwarded-for] = [***cleansed***] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[1] [Host] = [***cleansed***] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[2] [Connection] = [keep-alive] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[3] [User-Agent] = [Mozilla/5.0 (Windows NT >> 6.1; WOW64) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.57 >> Safari/536.11] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[4] [Accept] = >> [text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[5] [Accept-Encoding] = [gzip,deflate,sdch] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[6] [Accept-Language] = [en-US,en;q=0.8] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[7] [Accept-Charset] = >> [ISO-8859-1,utf-8;q=0.7,*;q=0.3] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[8] [Cookie] = [SSOTOKEN=***cleansed***] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[9] [SSO_LOGIN] = [***cleansed***] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[10] [SSO_ID] = [***cleansed***] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(290): >> ajp_marshal_into_msgb: Header[11] [SSO_EMAIL] = [***cleansed***] >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(450): >> ajp_marshal_into_msgb: Done >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(268): proxy: >> APR_BUCKET_IS_EOS >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(273): proxy: data to >> read (max 8186 at 4) >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(288): proxy: got 0 >> bytes of data >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(687): ajp_read_header: >> ajp_ilink_received 03 >> [Mon Jul 23 10:03:15 2012] [debug] ajp_header.c(697): ajp_parse_type: got >> 03 >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(460): Ignoring flush >> message received before headers >> [Mon Jul 23 10:03:15 2012] [error] (70014)End of file found: >> ajp_ilink_receive() can't receive header >> [Mon Jul 23 10:03:15 2012] [error] ajp_read_header: ajp_ilink_receive >> failed >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(549): (120006)APR does >> not understand this error code: ajp_read_header failed >> [Mon Jul 23 10:03:15 2012] [debug] mod_proxy_ajp.c(564): proxy: Processing >> of request failed backend: 1, output: 0 >> [Mon Jul 23 10:03:15 2012] [error] (120006)APR does not understand this >> error code: proxy: dialog to 127.0.0.1:7071 (127.0.0.1) failed >> [Mon Jul 23 10:03:15 2012] [debug] proxy_util.c(2029): proxy: AJP: has >> released connection for (127.0.0.1) >> [Mon Jul 23 10:03:15 2012] [debug] mod_deflate.c(615): [***cleansed***] >> Zlib: Compressed 323 to 218 : URL /myapp/ >> >> --------------------------------- >> Apache HTTP Server (apachectl -V) >> --------------------------------- >> Server version: Apache/2.2.22 (Unix) >> Server built: Jul 17 2012 17:20:28 >> Server's Module Magic Number: 20051115:30 >> Server loaded: APR 1.4.5, APR-Util 1.4.1 >> Compiled using: APR 1.4.5, APR-Util 1.4.1 >> Architecture: 64-bit >> Server MPM: Worker >> threaded: yes (fixed thread count) >> forked: yes (variable process count) >> Server compiled with.... >> -D APACHE_MPM_DIR="server/mpm/worker" >> -D APR_HAS_SENDFILE >> -D APR_HAS_MMAP >> -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) >> -D APR_USE_SYSVSEM_SERIALIZE >> -D APR_USE_PTHREAD_SERIALIZE >> -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT >> -D APR_HAS_OTHER_CHILD >> -D AP_HAVE_RELIABLE_PIPED_LOGS >> -D DYNAMIC_MODULE_LIMIT=128 >> -D HTTPD_ROOT="/apps/apache2" >> -D SUEXEC_BIN="/apps/apache2/bin/suexec" >> -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" >> -D DEFAULT_ERRORLOG="logs/error_log" >> -D AP_TYPES_CONFIG_FILE="conf/mime.types" >> -D SERVER_CONFIG_FILE="conf/httpd.conf" >> >> ------------------------------- >> httpd.conf (relevant settings): >> ------------------------------- >> <IfModule worker.c> >> StartServers 2 >> MaxClients 400 >> MinSpareThreads 25 >> MaxSpareThreads 75 >> ThreadsPerChild 25 >> MaxRequestsPerChild 10000 >> </IfModule> >> >> ProxyRequests Off >> ProxyPreserveHost on >> ProxyReceiveBufferSize 0 >> ProxyErrorOverride Off >> RewriteEngine on >> >> ProxyPass /myapp ajp://127.0.0.1:7071/myapp >> ProxyPassReverse /myapp ajp://127.0.0.1:7071/myapp >> >> ----------------------------------------------- >> tcServer 2.0.4.RELEASE (Tomcat 6.0.29 binaries) >> ----------------------------------------------- >> server.xml: >> >> <Executor name="tomcatThreadPool" namePrefix="tomcat-ajp--" >> maxThreads="300" minSpareThreads="50"/> >> <Connector executor="tomcatThreadPool" >> address="127.0.0.1" >> port="7071" >> protocol="org.apache.coyote.ajp.AjpAprProtocol" >> connectionTimeout="60000" >> redirectPort="8443" >> backlog="100" >> tcpNoDelay="true" >> enableLookups="false" >> URIEncoding="UTF-8" /> >> >> >> >> >> >> --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
