hm - my servers generally have no swap or better said only a 500 MB swap-file, they are all virtual machines in a ESXi cluster
you really do not want a VM swapping this leads in unusaeable performance in my case the problem was another process eating up all memory by user-mistake and my hint is to make sure in this case that this process get killed and never mysqld but i never ever had to reboot any linux guest to get it back to life Am 13.04.2012 16:27, schrieb Johnny Withers: > I had this same problem with the OOM for a while. Very frustrating to have to > reboot a server to bring it back to life. > > I found out the OOM only ran when the swap file was about 99% full. The > servers I had this problem on had 16GB and > 24GB of ram, but only 2GB of swap. I increased the swap on the 24GB servers > to 48GB and on the 16GB servers to > 32GB. The swap never fills to over 60% now and I haven't' had any OOM > problems since and the systems run great. > > I've also set vm.swappiness=0 in /etc/sysctl.conf > > -JW > > On Fri, Apr 13, 2012 at 7:17 AM, Reindl Harald <h.rei...@thelounge.net > <mailto:h.rei...@thelounge.net>> wrote: > > the following may be useful for most server systems > > OOM-killer acts if some process reclaims more and more > memory and the kernel randomly kills unimportant tasks > using hughe memory > > in case of a running mysqld the classification "unimportant" > is nearly all time wrong and can cause hughe damage and work > in other words: you really never want killed a database server > randomly instead "dbmail-imapd" which can be restarted via > systemd without pain and may be the root-cause of OOM > _________________________________________ > > with one single command you can protect processes from get killed > i started to run this every 15 minutes to make sure it is also > active after restarts > > i am considering include this in "mysqld.service" as > "ExecStartPost=-/usr/local/bin/mysql-no-oom.sh" in our > internal mysqld-packages and include also the script > _________________________________________ > > [root@mail:~]$ cat /etc/crontab | grep oom > 0,15,30,45 * * * * root bash /usr/local/bin/mysql-no-oom.sh > > [root@mail:~]$ cat /usr/local/bin/mysql-no-oom.sh > #!/bin/bash > pgrep -f "/usr/libexec/mysqld" | while read PID; do echo -1000 > > /proc/$PID/oom_score_adj; done > > > > > -- > ----------------------------- > Johnny Withers > 601.209.4985 > joh...@pixelated.net <mailto:joh...@pixelated.net>
signature.asc
Description: OpenPGP digital signature
