Open Stack

On 05/31/2017 11:06 PM, Mike Bayer wrote:
> I'd also throw in, there's lots of versions of Galera with different 
> bugfixes / improvements as we go along, not to mention configuration 
> settings.... if Jay observes it working great on a distributed cluster 
> and Clint observes it working terribly, it could be that these were not 
> the same Galera versions being used.

Agreed. The version of Galera we were using IIRC was Percona XtraDB 
Cluster 5.6. And, remember that the wsrep_provider_options do make a big 
difference, especially in WAN-replicated setups.

We also increased the tolerance settings for network disruption so that 
the cluster operated without hiccups over the WAN. I think the 
wsrep_provider_options setting was evs.inactive_timeout=PT30Sm 
evs.suspect_timeout=PT15S, and evs.join_retrans_period=PT1S.

Also, regardless of settings, if your network sucks, none of these 
distributed databases are going to be fun to operate :)

At AT&T, we jumped through a lot of hoops to ensure multiple levels of 
redundancy and high performance for the network links inside and between 
datacenters. It really makes a huge difference when your network rocks.

Best,
-jay