Bug #30830 ndb_mgm SHOW output should not output "Master" only

• Submitted: 5 Sep 2007 12:23
• Modified: 19 Nov 2008 13:36
• Reporter: Kai Voigt
• Status: Open
• Category: MySQL Cluster: Cluster (NDB) storage engine
• Severity: S4 (Feature request)
• Version: mysql-5.1-telco-7.0
• OS: Any
• CPU Architecture: Any
• Tags: all versions

[5 Sep 2007 12:23] Kai Voigt

Description:
The current heartbeat master of the data nodes is listed with "Master". This can be confused with Replication Master terminology.

Either remove this output or make it "Heartbeat Master".

How to repeat:
Run SHOW inside ndb_mgm and see "Master" being displayed with one of the data nodes.

[5 Sep 2007 12:31] Kai Voigt

any os

[5 Sep 2007 12:36] Jon Stephens

This has caused lots of confusion in the mailing lists/forums - people think they should be able to control which node is the master, that doing so can impact performance, etc.

(Of course, they're wrong - and the true state of affairs is reflected in the documentation - but there you are.)

[5 Sep 2007 12:38] Jon Stephens

I favour simply not showing this information, or displaying it only if ndb_mgm is started with some special option such as --verbose or --debug.

[19 Nov 2008 13:36] Kai Voigt

Here's the patch:

*** storage/ndb/src/mgmclient/CommandInterpreter.cpp.orig	Fri Sep 12 16:42:59 2008
--- storage/ndb/src/mgmclient/CommandInterpreter.cpp	Fri Sep 12 16:43:07 2008
***************
*** 1627,1633 ****
  	  if (node_state->node_group >= 0) {
  	    ndbout << ", Nodegroup: " << node_state->node_group;
  	    if (master_id && node_state->dynamic_id == master_id)
! 	      ndbout << ", Master";
  	  }
  	}
  	ndbout << ")" << endl;
--- 1627,1633 ----
  	  if (node_state->node_group >= 0) {
  	    ndbout << ", Nodegroup: " << node_state->node_group;
  	    if (master_id && node_state->dynamic_id == master_id)
! 	      ndbout << ", Heartbeat Master";
  	  }
  	}
  	ndbout << ")" << endl;