Automated Repair on multiple nodes

[Mohit Anchlia]

We currently run automated repairs sequentially on all the nodes. However,
as we grow the cluster we now need to run repair on multiple nodes in
parallel to be able to finish it withing gcgrace seconds. Before I write
the script I was wondering if somebody already has a tool or a script that
figures out nodes that we can safely run repairs on in parallel. For
instance we wouldn't run repair on replica nodes in parallel.