On Unix systems most daemon processes are written to trap a SIGHUP sent to their proccess ID (PID) and reinitialize. This is common behaviour and handy if you either need to propagate a change in the daemon's configuration, or want it to release locks or file handles. The latter is mostly required if you need to rotate logfiles of these processes, and thus also used by logrotate. You can look for logrotate's config file to change this. Usually it is either in a single file like /etc/logrotate.conf, or on many Linux systems spread over several files separated per service like e.g. /etc/logrotate.d/httpd or /etc/logrotate.d/apache The apache httpd is written to not only trap a SIGHUP but also a SIGUSR1 (a userdefined signal). How it behaves differently on reception of these signals can be read here see http://httpd.apache.org/docs/1.3/stopping.html Usually the graceful restart is to be preferred but it depends on what you are doing with the old logfile immediately after rotation (e.g. like zipping or post processing, read warning note in above doc) On a Unix system the command "kill" (which is a real misnomer and rather should have been named something like "sendsig") will list you all known signals along with their numbers by "kill -l" $ kill -l|grep -i usr1 9) SIGKILL 10) SIGUSR1 11) SIGSEGV 12) SIGUSR2 On a Linux box you can invoke a graceful restart like # pkill -10 -u 0 -P 1 -x httpd # tail -3 /var/log/httpd/error_log [Fri Aug 25 10:15:53 2006] [notice] SIGUSR1 received. Doing graceful restart [Fri Aug 25 10:15:53 2006] [notice] Apache/1.3.27 (Unix) PHP/4.4.1 configured -- resuming normal operations [Fri Aug 25 10:15:53 2006] [notice] Accept mutex: sysvsem (Default: sysvsem) -----Original Message----- From: Chidanand Gangur [mailto:chidanand.gangur@xxxxxxxxx] Sent: Friday, August 25, 2006 9:37 AM To: users@xxxxxxxxxxxxxxxx Subject: [users@httpd] Apache restarts on logrotate Hi all, I have configured apache with php and ssl. I have statically linked them in apache and using it for an embedded application. I have also configured logrotate to rotate the log files when the access_log/error_log reaches to 5M. I am using apache-1.3.34. Many times I see the following message in my error_log file. [notice] SIGHUP received. Attempting to restart after googling I found that SIGHUP is sent by logrotate when it clears and backups the file. I see this event every often. Does the process actually get restarted, or is reloaded? Some times I see that apache process hangs with limit of MaxClient reached. This condition sometime recovers over the period of time and some time does not. Is that the frequent restart of apache process causing this problem? When the condition arises I also tried to do netstat I see lot of stream sockets in connected state. UNIX stream sockets are openened in PHP script to talk to othe r modules in the system. unix 2 [ ] STREAM CONNECTED 8657659 22202/httpd unix 2 [ ] STREAM CONNECTED 8657655 9190/httpd unix 2 [ ] STREAM CONNECTED 8657654 22231/httpd unix 2 [ ] STREAM CONNECTED 8657653 669/httpd unix 2 [ ] STREAM CONNECTED 8657643 7228/httpd unix 2 [ ] STREAM CONNECTED 8657642 28418/httpd unix 2 [ ] STREAM CONNECTED 8657640 412/httpd unix 2 [ ] STREAM CONNECTED 8657637 32393/httpd unix 2 [ ] STREAM CONNECTED 8657636 25979/httpd unix 2 [ ] STREAM CONNECTED 8657635 19223/httpd unix 2 [ ] STREAM CONNECTED 8657634 17688/httpd unix 2 [ ] STREAM CONNECTED 8657628 5491/httpd unix 2 [ ] STREAM CONNECTED 8657623 10928/httpd unix 2 [ ] STREAM CONNECTED 8657622 30138/httpd unix 2 [ ] STREAM CONNECTED 8657620 514/httpd unix 2 [ ] STREAM CONNECTED 8657618 16177/httpd unix 2 [ ] STREAM CONNECTED 8657613 25896/httpd -- Chidanand Gangur Pune. --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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