Thanks Jason for information.
Clayton mentioned master need more memory. Not sure he mean by hosting both components and etcd is the main memory eater like you said.
What is redhat best recommended placement for production deployments? don’t see any reference architecture guide for OSE 3.X yet from redhat.
From: Jason DeTiberus <jdetiber redhat com>
Date: Wednesday, January 6, 2016 at 12:53 AM
To: skotaru <skotaru cisco com>
Cc: "dev lists openshift redhat com" <dev lists openshift redhat com>, "users lists openshift redhat com" <users lists openshift redhat com>
Subject: Re: master and etcd installation
That is the main tradeoff, saving hosts by co-residing the services vs. isolating the services.
Memory will be the main resource, etcd memory usage will grow with the cluster size and the number of resources deployed.
> - API traffic
Masters can be scaled independently from the etcd cluster and require less resources.
The only other consideration I see is that replacing a master host (outside of the master hosting the CA) does not require restoration of data from backup, where replacing an etcd host would (that, or the etcd cluster would need to be modified through etcdctl to add a new host and remove the old host).