mmm agent cannot connect to MySQL even when mmm agent user is already created on DB

[Gurvinder Dadyala]

I have made 2 DB nodes, 1 monitor node and i have 2 virtual IPs [192.168.100.196, 192.168.100.197]. When i start mmm-monitor on monitor node and other agents on DB nodes everything works well. MMM-monitor assigns writer role to DB1 and reader role to DB2. After 15 or 30 mins mmm-agent on assigned writer node starts throwing error message that it is not able to connect to MySQL. I am not sure why it does so because mmm-agent user is already created under both db nodes and mmm-agent does not throw this message when you start agents. It happens in between automatically after 15-30 mins. Following is the error message.

2011/06/08 14:01:16 FATAL Couldn't deny writes: ERROR: Can't connect to MySQL (host = 192.168.100.98:3306, user = mmm_agent)! Can't connect to MySQL server on '192.168.100.98' (4)

I have checked configuration files on both nodes and everything is good. Even i have deleted user credentials and created them again just to make sure it is not because of mmm-agent user credentials. This usually happens on node which has been assigned writer role. There is no fixed time for this error message. I am able to connect to both nodes after i start monitor and other agents. Agent DB with assigned writer role automatically starts throwing error that agent is not able to to MySQL and then after 5-6 min it works fine. I want to know is this a bug or something else is not right

[Kenny Gryp (gryp)]

The errorcode 4 is mentioned in your error.
This means that the code got interrupted, which indicates a timeout during the checks.

You might want to investigate connection time to mysql. or higher the timeout for the checks.

[Slava (slava-tangramltd)]

Try from monitor node connect to mysql.
And check DNS, if have delay.