On Thu, May 03, 2012 at 10:45:51AM -0400, John Nagro wrote: > Okay - and doing the upgrade to a live cluster? I can do that to 1 machine > at a time while the cluster is still online and everything should operate > as normal? I have 5 machines, use 3 at a time, quorum of 2. In terms of rolling restarts, if ensemble size if 3 and you have 5 machines, you can bring down one machine at a time and it'll be fine. Any clients writing to that machine will move very quickly to using one of the other machines (it'll see the network drop, and rebuild an ensemble from the other machines).
Regarding whether you need to run the upgrade code, it depends on what the old version of bookkeeper you are using is. If you need to run upgrade, the bookie will warn you and fail to start. https://issues.apache.org/jira/browse/BOOKKEEPER-163 is actually the change that requires the upgrade framework. -Ivan
