On Wed, 7 May 2008, Krishna Srinivas wrote:
> Is this an issue in server-side-only AFR? I have two servers which
> are also clients of themselves, and they both list their local
> subvolume first and
> remote subvolume second. Is this a problem? What are the possible
> consequences of this?
It will be a problem. The "first" subvol is always the "lock" server.
Consider a case where you are creating a file simultaneously
on two clients, only one of them should succeed. If AFR's
subvols order are not same, chances are that both client
returns success for file creation with same name.
Hence you have "option read-subvlume" to speeden the
read() calls so that it can be done from local subvol.
So, what happens if the "lock" server is the one that goes down? Will that
render the whole AFR cluster inoperable, at least for writes?
If first server is down, the second one is tried and so on. The cluster remains
operable.
Does the lock state remain for the locks when the primary/lock server
dies? If so, how?
Gordan
