Comments on: Watch out for your CRON jobs http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/ Everything about MySQL Performance Thu, 29 Jul 2010 19:06:57 +0000 http://wordpress.org/?v=13 hourly 1 By: XCondE http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-668481 XCondE Sat, 24 Oct 2009 08:32:55 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-668481 man 1 flock flock [-sxon] [-w timeout] lockfile [-c] command... */5 * * * * flock -xn /var/lock/mylockfile -c my-shell-script.sh Only one will ever run. You can also tell it to wait instead of bailing out: */5 * * * * flock -x /var/lock/mylockfile -c my-shell-script.sh Or wait only 30 secs: */5 * * * * flock -x -w 30 /var/lock/mylockfile -c my-shell-script.sh man 1 flock
flock [-sxon] [-w timeout] lockfile [-c] command…

*/5 * * * * flock -xn /var/lock/mylockfile -c my-shell-script.sh

Only one will ever run. You can also tell it to wait instead of bailing out:

*/5 * * * * flock -x /var/lock/mylockfile -c my-shell-script.sh

Or wait only 30 secs:

*/5 * * * * flock -x -w 30 /var/lock/mylockfile -c my-shell-script.sh

]]> By: mikhail panchenko / blog » Blog Archive » “Watch out for your CRON jobs” @ MySQL Performance Blog http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-666749 mikhail panchenko / blog » Blog Archive » “Watch out for your CRON jobs” @ MySQL Performance Blog Tue, 20 Oct 2009 05:40:58 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-666749 [...] Watch out for your CRON jobs [...] [...] Watch out for your CRON jobs [...]

]]> By: Sheeri K. Cabral http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-666535 Sheeri K. Cabral Mon, 19 Oct 2009 13:54:09 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-666535 Peter, Many people have shell/perl/php/python/ruby scripts that are cron jobs that only do database reads/writes, and can be converted to MySQL Events. Obviously if there are actions outside MySQL, it's not useful as a MySQL Event. Pythian actually mitigates this issue by monitoring long-running OS processes. Peter,

Many people have shell/perl/php/python/ruby scripts that are cron jobs that only do database reads/writes, and can be converted to MySQL Events.

Obviously if there are actions outside MySQL, it’s not useful as a MySQL Event.

Pythian actually mitigates this issue by monitoring long-running OS processes.

]]> By: Fourat http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-666331 Fourat Sun, 18 Oct 2009 23:59:55 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-666331 A more secure way to lock/unlock your script is to use register_shutdown_function() at the begin to register the action to be done on the end. A more secure way to lock/unlock your script is to use register_shutdown_function() at the begin to register the action to be done on the end.

]]> By: The CRONs task | Ansermot.ch http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-666206 The CRONs task | Ansermot.ch Sun, 18 Oct 2009 11:27:45 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-666206 [...] the post Share and [...] [...] the post Share and [...]

]]> By: peter http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-665842 peter Sat, 17 Oct 2009 03:16:58 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-665842 Sheeri, I am mainly speaking about shell/perl/php/python/ruby scripts a lot of systems are running. If you just need simple query/stored procedure run you can use MySQL events of course. Sheeri,

I am mainly speaking about shell/perl/php/python/ruby scripts a lot of systems are running. If you just need simple query/stored procedure run you can use MySQL events of course.

]]> By: Sheeri K. Cabral http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-665770 Sheeri K. Cabral Fri, 16 Oct 2009 22:40:00 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-665770 I'm surprised you didn't recommend using MySQL events -- many people are on 5.0 or higher and can use them. Errors are put into the error log (which I recommend monitoring, at Pythian we monitor error logs, and we can specify 'noise' to ignore like if there's a lot of "aborted connects", so we see the important things), so that issues is resolved. In fact, the times that the event started and finished are also logged in the error log, so there is a historical log of how long things take. I’m surprised you didn’t recommend using MySQL events — many people are on 5.0 or higher and can use them. Errors are put into the error log (which I recommend monitoring, at Pythian we monitor error logs, and we can specify ‘noise’ to ignore like if there’s a lot of “aborted connects”, so we see the important things), so that issues is resolved.

In fact, the times that the event started and finished are also logged in the error log, so there is a historical log of how long things take.

]]> By: Watch out for your CRON jobs | blog's amazing http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-665206 Watch out for your CRON jobs | blog's amazing Thu, 15 Oct 2009 11:00:00 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-665206 [...] details and code sample in Watch out for your CRON jobs at MySQL Performance [...] [...] details and code sample in Watch out for your CRON jobs at MySQL Performance [...]

]]> By: peter http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-665129 peter Thu, 15 Oct 2009 04:01:44 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-665129 Joy, Yes. I see no problem with using semaphores if you prefer. I do not like it as much as it is harder to see the status of semaphores using command line tools. Joy,

Yes. I see no problem with using semaphores if you prefer. I do not like it as much as it is harder to see the status of semaphores using command line tools.

]]> By: peter http://www.mysqlperformanceblog.com/2009/10/14/watch-out-for-your-cron-jobs/comment-page-1/#comment-665128 peter Thu, 15 Oct 2009 04:00:41 +0000 http://www.mysqlperformanceblog.com/?p=1410#comment-665128 Neven, Right. There are possible issues. Though a lot of systems out there even at the large scale would run only one operation system or may be the couple. The GearMan is indeed great solution but I think it is overkill for a lot of simple tasks. Neven,

Right. There are possible issues. Though a lot of systems out there even at the large scale would run only one operation system or may be the couple.

The GearMan is indeed great solution but I think it is overkill for a lot of simple tasks.

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