I can confirm that there were no domains used for our permissions. All
IP based. Although this may have been the cause, I don't think it was
in this case. I think as well that DNS timeouts are in the region of 20
seconds to 2 minutes.
Would any person know if there is any other part of MySQL which uses DNS
lookups? For instance, logging of some kind?
Or any other reason a MySQL daemon would not respond to a kill?
Thank for the ideas,
Jigal van Hemert wrote:
> Ben Clewett wrote:
>> It had been suggested that our DNS failed prior to this event. I
>> don't think MySQL uses DNS, but I am not entirely sure.
> If the db, user, etc. tables in the mysql system database (containing
> privileges, etc.) contain host names instead of IP-addresses I suspect
> it needs a DNS to resolve these...
>> If I get a state where a 'kill' will not cause MySQL to exit. Is
>> there any other know way to ask MySQL to exit cleanly?
> MySQL server was probably waiting for a bunch of DNS requests? Until a
> timeout occurs it will probably keep the connection waiting. This can
> cause a lot of connections to occur until you reach max_connections at
> which point it will not accept new connections anymore.
> Regards, Jigal.