Bug #41933 Large lists of databases break initial agent data item discovery
Submitted: 7 Jan 2009 21:08 Modified: 13 Jan 2009 16:37
Reporter: Mark Leith Email Updates:
Status: Closed Impact on me:
Category:MySQL Enterprise Monitor: Server Severity:S2 (Serious)
Version: OS:Any
Assigned to: Darren Oldag CPU Architecture:Any

[7 Jan 2009 21:08] Mark Leith
Starting a new agent against an instance that contains a lot of databases breaks up the initial discovery packet (like Bug #41314), causing collections such as CPU usage (and their graphs) to fail. 

This also relates to Bug #33150.

How to repeat:
o Set up an instance with 1000 databases
o Start an agent against it
o Check whether all of the graphs get data correctly

Suggested fix:
Do not ask for the list of databases yet, they're not used in the server at the moment anyway.
[8 Jan 2009 23:12] Darren Oldag
patches pushed to trunk.  merge in progress to 2.0 maint tree.

don't ask for database instances in initial discovery, but utilize the server->databases drilldown mechanism already in place.


disabled even the drill-down discovery of database instances, as
  nothing exists in MEM to use it yet, and even if it did -- the rules
  infrastructure is not very suitable to writing generic rules on database
  instances anyway.
  the setting to fetch DBs is controlled by a manager property setting.
  by default, it will not fetch databases or table.  then, you can optionally
  enable just database level inventory.  or, if you feel dangerous, enable
  databases AND tables.
  databaseInventoryLevel = NONE
  databaseInventoryLevel = DATABASE
  databaseInventoryLevel = DATABASE_TABLE
  perhaps, one day, when db inventory is useful, we can expose setting this
  in the UI.  for now, it would have to be backdoor'd via the repository
  or the REST property settter.
[8 Jan 2009 23:38] Darren Oldag
patch merged to 2.0 maint branch, awaiting build.
[12 Jan 2009 17:04] Bill Weber
verified it doesn't log db instances during initial discovery in build
[13 Jan 2009 16:37] Tony Bedford
An entry was added to the 2.0 changelog:

Starting a new agent against an instance that contained many databases broke up the initial discovery packet, causing collections such as CPU usage and their graphs to fail. See also Bug#33150 and Bug#41314.