Description:
One thing that is severely missing from merlin at the moment is the ability to see the current "static" (from the appropriate my.cnf configuration files) and "running configuration" of each server.
With this information you can compare servers and report on differences.
How to repeat:
N/A
Suggested fix:
Obtaining the running configuration is trivial because all you need to do is to do: SHOW GLOBAL VARIABLES. The static configuration requires you finding the my.cnf files in the right order and getting the values to be evaluated and stored. I think this is done via mysql_print_defaults.
EVERY change to these 2 sets of values SHOULD be kept and recorded (changes aren't that frequent).
Advisors should WARN:
- when the static OR running configuration changes in any way
- when the static OR running configuration differ (this is slightly more difficult to do properly as some of the static configuration variables are not shown in SHOW GLOBAL VARIABLES
It should also be possible to:
- COMPARE either static or running configurations of 2 servers
- to list a similar variable on all servers (or a group) so the sys admin can see if similar servers are configured identically.
- to check a configuration set on one or more servers against a reference server configuration, again warning if there is a difference.
This information would be invaluable when running a large number of instances as it is quite easy to inadvertently configure a server incorrectly and not notice for some time.
