[Gluster-devel] Bumping down cluster op-version in glusterd

[Atin Mukherjee]

Folks,

As of now we do not have a way to bump down cluster's op-version. We
bump up the op-version using gluster volume set command whenever a node
is upgraded in the cluster. However I do a see a need of having support
for bumping down the op-version. In past we have encountered lots of
bugs in heterogeneous cluster testing. Most of the time either we forget
to think of backward compatibility or ignore them with a mentality of
fixing the bugs later.

I've posted a patch [1] which introduces 'force' option in volume set by
which cluster's op-version can be bumped down. With that we can write
test cases to hit those code paths which are placed for backward
compatibility and we rarely hit them in testing.

Please let me know your thoughts on this.

[1] http://review.gluster.org/10949

P.S : gluster volume set all cluster.op-version <value> force should
never be run until and unless it requires backward compatibility testing.
-- 
~Atin