On Tue, Mar 16, 2010 at 5:08 PM, Todd Lipcon <t...@cloudera.com> wrote: > > What do you think about the trick of making the RS do a ZK sync before any > meta op? This forces it to take at most one action after it's been > terminated. >
... where meta op is open of new WAL log? How would this work? RS would note in ZK the name of the WAL its about to open before it did it? If the RS then does a "Juliet" -- i.e. goes into a GC pause death-like coma -- on revivial, it'll go to open the WAL but master will have already done so, and so it'll fail? @Karthik "I am a little nervous about the master backing off on detecting the RS's progress - because the RS has already lost its zk lease." Yes. The RS will have had its 'shut-yourself-down' flag set on loss-of-lease so is on its way out. Its not going to revive so its logs need recovering. @Kannan "Option #1 seems easy to reason about and simple to implement. Can we go ahead with that if there is no major objection?" Fine by me. St.Ack
