Use galera in aio model

In order to ensure mysql is configured with settings
close to production once we need to use galera in AIO
model in single master mode.
As was found during tempest tests runs Mysql DB doesn't
exceed 105 MB and there are no more than 
120 concurrent connections to DB. So in order to have some
spare capacity for mysql - max connections are set to 1000
and pool size to 1024MB.

Change-Id: Ifc0189935a89222def3663b8fbbdcdb13d8dd9bf
Related-Prod: PROD-14716
3 files changed