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On 12/09/2016 04:49 PM, Pradeep Kilambi wrote:
> Hey Folks:
>
> I would like to get some thoughts on $Subject. This came up when i was
> discussing the standalone roles for telemetry. Currently when we deploy
> redis in tripleo, its a pacemaker managed service. So if we were to
> deploy telemetry services on a dedicated node we could. But redis will
> have to be on a another node? (assuming we dont want to pull in
> pacemaker on to telemetry nodes).

currently redis instances are not configured as a redis cluster but use 
the master/slave replication model instead and pacemaker is taking care 
of electing/relocating the redis master as needed

there shouldn't be any dependency on the redis profile for the telemetry 
roles, they should instead just point at the redis_vip

the redis_vip is always guaranteed (by haproxy) to point to the redis master

> With most services moved out of pacemaker in Newton, I think its time to
> move redis as well? Are there any constraints in moving redis to be
> managed by systemd? Looking at how we do it, It should be easily movable
> to systemd? Can we consider doing this for Ocata?

I think we could look at using the redis cluster which allows multiple 
masters, but I am not sure this can happen in Ocata ... yet again, there 
shouldn't be in the telemetry roles any dependency on redis itself

if we were to use the cluster mode the only difference would probably be 
that the redis_vip will start balancing requests across the nodes
-- 
Giulio Fidente
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