after master recovery the host don't get his reader role

Bug #385223 reported by jfdusar on 2009-06-09
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Pascal Hofmann

Bug Description

This is happening with mysql-mmm 2.0.5

We have a 4 node config (master-master-slave-slave). When we shutdown the active master by stopping mysql for about 10 seconds. The writer role is switched to the other master and the reader role to any other node. When mysql is getting back, it recover the writer role, but the reader role don't come back.

Since the reader role is balanced I expected that the role are distributed equaly on each node. I think that was OK on MMM1.

If needed I can provide logs.

Related branches

Pascal Hofmann (pascalhofmann) wrote :

You are using the "preferred host" feature, right?

Changed in mysql-mmm:
assignee: nobody → Pascal Hofmann (pascalhofmann)
jfdusar (jfdusar) wrote :

no since the reader role is in "balanced" mode. It's really the reader role that is our problem here ... We really want it to be balanced among all the available hosts.

Pascal Hofmann (pascalhofmann) wrote :

Why did MMM switch the writer role back to master1? It should only do this if master1 is specified as preferred host in the config.

Pascal Hofmann (pascalhofmann) wrote :

Should be fixed in 2.0.6. See

Changed in mysql-mmm:
status: New → Fix Released
jfdusar (jfdusar) wrote :

My problem is not the writer, but the reader role that don't comeback to master1. And yes in my config master1 is prefered for writer role.
The fact is that I need to be sure that the reader roles are well balanced among the online nodes. Can you point me the fix that you did to fix this.


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