MySQL Bugs: #38399: Agent to MySQL server connection is poorly documented

Bug #38399	Agent to MySQL server connection is poorly documented
Submitted:	28 Jul 2008 9:47	Modified:	4 Feb 2009 17:08
Reporter:	Axel Schwenke	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Enterprise Monitor: Documentation	Severity:	S3 (Non-critical)
Version:	1.3.2	OS:	Any
Assigned to:	Tony Bedford	CPU Architecture:	Any

Description:
There are two issues here that need better documentation:

1. contrary to most (all?) other clients, the agent does not treat "localhost" special. I.e. the command line client uses the UNIX domain socket for localhost, but the agent tries the TCP socket at 127.0.0.1. While this behavior might be intended, it is still not documented.

2. the agent is still capable of connecting via the UNIX domain socket, if there is a "socket=/full/path/to/mysql.sock" line in the [mysqld] section of the agent ini file. This option is not documented at all.

How to repeat:
Run the MySQL server with skip-networking. Then the agent cannot connect, but the command line client with (seemingly) the same credentials can.

Add a line "socket=/full/path/to/mysql.sock" to the agent ini file. Now the agent can connect to the MySQL server.

Suggested fix:
Extend the agent documentation:

- explain that the agent uses TCP socket by default and is thus not compatible with skip-networking and bind-address
- add documentation about the socket option

See related bug #40530 (leaving this open against 1.3.2)

The 2.0 documentation has now been updated.

1.3 documentation now also updated.