Re: MySQL monitoring: too many bad connections from host

[Jan-Henrik Haukeland]

On Mar 30, 2005, at 10:08, Neil Robst wrote:

> I've setup monit 4.4 on a host to monitor a local MySQL database and a
> remote MySQL database by simply attempting to connect on port 3306 on 
> each
> server. I left it running over night and when I came back in this 
> morning
> I find that the MySQL database has blocked client accesses from the 
> host
> due to "too many bad connections". I suspect this is because the test 
> that
> monit is doing is simply opening the MySQL port and then closing it 
> again
> - not actually executing any SQL statements and thus MySQL is seeing 
> this
> as a bad connection attempt.

That sounds logical, but maybe it's something that could be configured 
in mysql?

> Is anyone aware of this and have a workaround / resolution?

I don't know much about mysql, but if you find an answer please let us 
know.

> Maybe extending the MySQL tests like the Apache-status one to actually 
> query the
> status of the MySQL server and find out what it's really doing rather 
> than
> just connecting on the tcp port. Or maybe better still the ability to 
> run
> arbitary SQL statements and check their output?

That would be easy to add if monit was linked with the mysql C-library. 
However, we want to link with as few external libraries as possible to 
avoid dll-hell. We could have linking as an option in the configure 
script, but a much better idea is to implement or use a type 4 JDBC 
protocol interface, since they do not link with any native code and use 
a plain tcp connection protocol. If anyone have a protocol description 
or doc for the mysql JDBC connection, or want to implement a mysql test 
let us know.

--
Jan-Henrik Haukeland
Mobil +47 97141255