Re: SQL deadlock

[Jan-Henrik Haukeland]

This scaling doc has some tips for M/Monit, 
https://mmonit.com/wiki/MMonit/FAQ#scaling. MariaDB has been problematic in the 
past and we recommend using MySQL or Postgres if possible. Moving the database 
to a physical instance could also help. 


> On 29 Oct 2019, at 14:22, David Jones <address@hidden> wrote:
> 
> I have about 900 monit hosts reporting to a single M/monit VM running CentOS 
> 7.7.  I had to tune out (expand) the network port ranges to handle the 
> simultaneous connections.  Now I have to use monit itself to restart the 
> mmonit service several times a day when this shows up in /var/log/messages.  
> Is there any documentation or guidelines for setting up and tuning the 
> MariaDB 5.5 database server?  I have a local database on the VM but I could 
> move the DB to a more powerful, physical MariaDB 10.3 cluster if needed.
>  
> Oct 29 08:02:08 monit01 mmonit[3956]: SQLException: Deadlock found when 
> trying to get lock; try restarting transaction when storing hostid 12020 
> statistics
> Oct 29 08:02:08 monit01 mmonit: SQLException: Deadlock found when trying to 
> get lock; try restarting transaction when storing hostid 12020 statistics
> Oct 29 08:02:21 monit01 mmonit[3956]: SQLException: Deadlock found when 
> trying to get lock; try restarting transaction when storing hostid 6928 
> statistics
> Oct 29 08:02:21 monit01 mmonit: SQLException: Deadlock found when trying to 
> get lock; try restarting transaction when storing hostid 6928 statistics
>  
> Thanks,
> Dave