On Thu, Oct 8, 2015 at 7:44 AM, Caraballo, Rafael < rafael.caraba...@twcable.com> wrote:
> When planning an upgrade on a 20 node multi DC cluster from Cassandra 1.x > to Cassandra 2.x version, does the order of running upgradesstables matter? > > > > What is the difference between: > > (a) upgrade Cassandra and run upgradesstables one node at a time; > > -versus- > > (b) upgrade every Cassandra node, then start the upgradesstables one node > at a time? > This is becoming a FAQ, I should write a blog post... Briefly, until upgradesstables is done, one must assume that streaming operations will fail. Streaming is used in bootstrap, decommission and repair. Bootstrap is required to replace or add nodes, decommission is required to remove nodes, and repair is required once every gc_grace_seconds. One must balance the overhead of running upgradesstables simultaneously on multiple nodes with the duration of exposure to inability-to-use streaming. Often this means running upgradesstables in parallel on all hosts simultaneously. =Rob
