[Pacemaker] Getting Started

[Brett Maton]

On 3 Dec 2012, at 15:01, Florian Crouzat wrote:

> Le 03/12/2012 15:24, Brett Maton a écrit :
>> Hi List,
>> 
>>   I'm new to corosync / pacemaker so please forgive my ignorance!
>> 
>>   I currently have Postgres streaming replication between node1(master) and node2(slave, hot standby), the replication user authenticates to master using an md5 password.
>>   All good there...
>> 
>>   My goal use pacemaker / heartbeat to move VIP and promote node2 if node1 fails, without using drdb or pg-pool.
>> 
>>   What I'm having trouble with is finding resources for learning what I need to configure with regards to corosync / pacemaker to implement failover.  All of the guides I've found use DRDB and/or a much more robust network configuration.
>> 
>> I'm currently using CentOS 6.3 with PostgreSQL 9.2
>> 
>> corosync-1.4.1-7.el6_3.1.x86_64
>> pacemaker-1.1.7-6.el6.x86_64
>> 
>> node1	192.168.0.1
>> node2	192.168.0.2
>> dbVIP	192.168.0.101
>> 
>> Any help and suggested reading appreciated.
>> 
>> Thanks in advance,
>> Brett
>> 
> 
> Well, if you don't need shared storage and only a VIP over which postgres runs, I guess the official guide should be good:
> http://clusterlabs.org/doc/en-US/Pacemaker/1.1-crmsh/html-single/Clusters_from_Scratch/
> 
> Forget the drdb stuff, and base your configuration on the httpd examples that collocates a VIP and an httpd daemon in an active/passive two nodes cluster. (Chapter 6).
> 
> 
> -- 
> Cheers,
> Florian Crouzat

Thanks for the answers, I'll try again using crm / cman.  I've found a pgsql agent patched by Takatoshi Matsuo which should work if I can figure out the configuration!

Part of the problem I think is that PostgreSQL streaming replication is kind of active / active insofar as the slave is up and listening (and receiving updates from the master) in read only mode.

The default agent from the CentOS repositories kills the slave if the master is up, which means that replication doesn't happen as there is no slave to receive updates :)

Thanks,
Brett