I get occasional Apache 2 crashes being caused by mod_jk and I'm running out of ideas about the cause of the problem. I hope somebody here can point me in the right direction.
-Michael tomcat6 6.0.39-1 libapache2-mod-jk 1:1.2.37-3 apache2 2.4.7-1ubuntu4 java version "1.6.0_45" Java(TM) SE Runtime Environment (build 1.6.0_45-b06) Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed mode) /var/log/apache2/error.log **** buffer overflow detected ***: /usr/sbin/apache2 terminated======= Backtrace: =========/lib/x86_64-linux-gnu/libc.so.6(+0x7329f)[0x7fe9aa7de29f]/lib/x86_64-linux-gnu/libc.so.6(__fortify_fail+0x5c)[0x7fe9aa875bbc]/lib/x86_64-linux-gnu/libc.so.6(+0x109a90)[0x7fe9aa874a90]/lib/x86_64-linux-gnu/libc.so.6(+0x10ab07)[0x7fe9aa875b07]/usr/lib/apache2/modules/mod_jk.so(jk_open_socket+0x8d8)[0x7fe9a7c60cb8]/usr/lib/apache2/modules/mod_jk.so(ajp_connect_to_endpoint+0x65)[0x7fe9a7c7bf75]/usr/lib/apache2/modules/mod_jk.so(+0x36422)[0x7fe9a7c7d422]/usr/lib/apache2/modules/mod_jk.so(+0x1674c)[0x7fe9a7c5d74c]/usr/sbin/apache2(ap_run_handler+0x40)[0x7fe9ab65fbe0]/usr/sbin/apache2(ap_invoke_handler+0x69)[0x7fe9ab660129]/usr/sbin/apache2(ap_process_async_request+0x20a)[0x7fe9ab6756ca]/usr/sbin/apache2(+0x69500)[0x7fe9ab672500]/usr/sbin/apache2(ap_run_process_connection+0x40)[0x7fe9ab669220]/usr/lib/apache2/modules/mod_mpm_event.so(+0x681b)[0x7fe9a783981b]/lib/x86_64-linux-gnu/libpthread.so.0(+0x8184)[0x7fe9aab38184]/lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7fe9aa86537d]* ======= Memory map: ======== 7fe688000000-7fe68806a000 rw-p 00000000 00:00 0 7fe68806a000-7fe68c000000 ---p 00000000 00:00 0 ....... 7fffa6c27000-7fffa6c48000 rw-p 00000000 00:00 0 [stack] 7fffa6c86000-7fffa6c88000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] [Wed Jun 29 05:01:50.052325 2016] [core:notice] [pid 1747:tid 140641581987712] AH00051: child pid 17018 exit signal Aborted (6), possible coredump in /etc/apache2 The log indicates there might be a coredump, but there is not. There is no log in /var/log/apache2/mod_jk.log at the same time. /var/log/tomcat6/catalina.out Jun 29, 2016 5:01:49 AM org.apache.jk.common.ChannelSocket processConnection WARNING: processCallbacks status 2 Jun 29, 2016 5:01:49 AM org.apache.jk.common.ChannelSocket processConnection WARNING: processCallbacks status 2 The Tomcat log indicates AFAIK that the client connection has been lost. /etc/libapache2-mod-jk/httpd-jk.conf <IfModule jk_module> JkWorkersFile /etc/libapache2-mod-jk/workers.properties JkLogFile /var/log/apache2/mod_jk.log JkLogLevel warn JkShmFile /var/log/apache2/jk-runtime-status </IfModule> /etc/libapache2-mod-jk/workers.properties workers.tomcat_home=/usr/share/tomcat6 workers.java_home=/usr/lib/jvm/java-6-sun ps=/ worker.list=loadbalancer worker.loadbalancer.type=lb worker.loadbalancer.balance_workers=ajp13_worker,ajp13_worker2 worker.loadbalancer.sticky_session=0 worker.ajp13_worker.port=xxx worker.ajp13_worker.host=localhost worker.ajp13_worker.type=ajp13 worker.ajp13_worker.lbfactor=50 worker.ajp13_worker.max_packet_size=65536 worker.ajp13_worker.socket_timeout=300 worker.ajp13_worker.ping_mode=A worker.ajp13_worker.secret=xxx worker.ajp13_worker.fail_on_status=503 worker.ajp13_worker.connection_pool_size=32768 #worker.ajp13_worker.activation=disabled worker.ajp13_worker.redirect=ajp13_worker2 worker.ajp13_worker2.port=xxx worker.ajp13_worker2.host=otherhost worker.ajp13_worker2.type=ajp13 worker.ajp13_worker2.lbfactor=1 worker.ajp13_worker2.max_packet_size=65536 worker.ajp13_worker2.socket_timeout=300 worker.ajp13_worker2.ping_mode=A worker.ajp13_worker2.secret=xxx worker.ajp13_worker2.fail_on_status=503 worker.ajp13_worker2.connection_pool_size=32768 worker.ajp13_worker2.activation=disabled #worker.ajp13_worker2.redirect=ajp13_worker /etc/tomcat6/server.xml <Connector port="xxx" protocol="AJP/1.3" redirectPort="8443" enableLookups="false" maxThreads="65536" minSpareThreads="25" maxSpareThreads="75" connectionTimeout="300000" packetSize="65536" request.secret="xxx" /> ls /etc/apache2/mods-enabled/ access_compat.load auth_basic.load authz_core.load autoindex.conf deflate.load env.load headers.load mime.conf mpm_event.load rewrite.load socache_shmcb.load status.conf alias.conf authn_core.load authz_host.load autoindex.load dir.conf expires.load jk.conf mime.load negotiation.conf setenvif.conf ssl.conf status.load alias.load authn_file.load authz_user.load deflate.conf dir.load filter.load jk.load mpm_event.conf negotiation.load setenvif.load ssl.load lsb_release -rd Description: Ubuntu 14.04.4 LTS Release: 14.04