[CORD-1530]
Make config file directory creation using become an optional step
Cleanup various incongruities in defaults

Change-Id: I6fb77ab1ccdf08a18468adbc59474f94d603fc11
diff --git a/roles/juju-setup/templates/juju_config.yml.j2 b/roles/juju-setup/templates/juju_config.yml.j2
index bf157ea..e91e5c2 100644
--- a/roles/juju-setup/templates/juju_config.yml.j2
+++ b/roles/juju-setup/templates/juju_config.yml.j2
@@ -54,7 +54,8 @@
   openstack-origin: "cloud:trusty-kilo"
 
 percona-cluster:
-  max-connections: 20000
+  max-connections: 5000
+  innodb-buffer-pool-size: "20%"
 
 rabbitmq-server:
   ssl: "on"