Bug #26175 "Agent Not Communicating With Database Server" doesn't generate any event
Submitted: 8 Feb 2007 2:07 Modified: 21 Feb 2007 19:10
Reporter: Kolbe Kegel Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Enterprise Monitor: Agent Severity:S2 (Serious)
Version:1.0.1.4391 OS:
Assigned to: Jan Kneschke CPU Architecture:Any

[8 Feb 2007 2:07] Kolbe Kegel 
Description:
The "Agent Not Communicating With Database Server" Advisor does not seem to actually generate an Event if it is triggered.

This seems like a bad thing, since it means there will be no Email Notifications if the agent process simply dies outright, and thus no way to know if the underlying MySQL server is operational or not.

How to repeat:
Simply kill the agent process and observe the Dashboard.

Suggested fix:
There should be an Event generated if the Agent stops contacting the Server, and the Event should send Email Notifications if those are configured.
[8 Feb 2007 18:40] Kolbe Kegel 
Not sure if this problem is actually related to the "Agent Not Communicating With Database Server" rule.

The real issue here seems to be that the inability of the monitoring server to contact the agent does *not* cause any event to be generated, which means no emails are sent if the machine, operating system, intermediate network hardware, etc. become incapacitated or unavailable.
[8 Feb 2007 20:42] Mark Leith 
"Agent Not Communicating With Database Server" is actually for when the agent is up and running, and the database is up and running - but the agent can not connect to the database for some reason - max connections, access denied etc.

What you are describing is handled by the "MySQL Agent Not Reachable" rule - which does work as expected - sending an email when events are raised.

However, there were some issues with how "Agent Not Communicating With Database Server" was dealing with communications problems with the MySQL server it was monitoring.

I discussed this with Jan, who has already sorted this out (I think), by rejigging how the agent manages the connection errors (setting server.reachable / SERVER_REACHABLE). 

I'm reassigning this to Jan, so that he can update this bug once finished.
[8 Feb 2007 20:49] Mark Leith 
Clarifying, just for Kolbe, that "MySQL Agent Not Reachable" is a newly implemented advisor, and will be available within the next advisor bundle.
[8 Feb 2007 21:38] Jan Kneschke 
The problem has been fixed in the svn-tree and is currently tested.
[15 Feb 2007 17:08] Jan Kneschke 
it should be fixed in 1.1.0-r4682
[21 Feb 2007 19:10] Mark Leith 
Verified fixed in 1.1.0.4810