For quite some time I’ve been having a problem with my httpd.pid file going missing every now and then. Whenever this happens, I can’t use the init script to start and stop the server anymore, which is pretty annoying. For some reason I had learned to live with this – I would just ‘killall httpd’, start the server again and the httpd.pid would be back for some time, until the problem would reappear.<\/p>\n
Finally I decided to do something about it. I added this small script to my hourly cron jobs:<\/p>\n
\r\nif [ ! -e \"\/usr\/local\/apache2\/logs\/httpd.pid\" ]; then\r\n echo \"httpd.pid missing\"\r\nfi\r\n<\/pre>\nA few weeks later this trap was finally triggered – less than an hour after my daily logrotate, which produced this output:<\/p>\n
\r\nStarting httpd: [ OK ]\r\nStopping httpd: [ OK ]\r\n(repeated a number of times...)\r\nStarting httpd: [ OK ]\r\nStopping httpd: [FAILED]\r\nStarting httpd: (98)Address already in use: AH00072: make_sock: could not bind to address [::]:80\r\n(98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80\r\nno listening sockets available, shutting down\r\nAH00015: Unable to open logs\r\n[FAILED]\r\nerror: error running postrotate script for \/usr\/local\/apache2\/logs\/*_log \r\n<\/pre>\nThis was not the first time I had seen this, but it was the first time I realized that the logrotate problem was causing the httpd.pid problem, and not the other way around.<\/p>\n
So I checked my \/etc\/logrotate.d\/apache config file:<\/p>\n
\r\n\/usr\/local\/apache2\/logs\/*_log {\r\n rotate 1024\r\n size 4M\r\n notifempty\r\n postrotate\r\n \/etc\/init.d\/httpd restart\r\n endscript\r\n}\r\n<\/pre>\nAfter a few minutes of reading the logrotate man page, I realized what was wrong (had a hunch, though): The restart between the postrotate\/endscript<\/strong> directives was performed for each logfile, i.e. multiple times, instead of just a single time after the last one was rotated. This in itself is pretty bad, but it would also happen asynchronously, thus create a mess. This problem was easily solved using the sharedscript<\/strong> directive. Also, a simple “reload” instead of “restart” is sufficient to make httpd reopen the logfiles, thus create new filehandles.<\/p>\n
After fixing these two problems, the file ended up like this:<\/p>\n
\r\n\/usr\/local\/apache2\/logs\/*_log {\r\n rotate 1024\r\n size 4M\r\n notifempty\r\n sharedscripts\r\n postrotate\r\n \/etc\/init.d\/httpd reload\r\n endscript\r\n}\r\n<\/pre>\nI’m fully expecting this to solve the problem once and for all.<\/p>\n","protected":false},"excerpt":{"rendered":"
For quite some time I’ve been having a problem with my httpd.pid file going missing every now and then. Whenever this happens, I can’t use the init script to start and stop the server anymore, which is pretty annoying. For … Continue reading