On Fri, Oct 6, 2017 at 6:35 PM, Venkateswara Rao Jujjuri <jujj...@gmail.com> wrote: >> However, imagine that the fenced message is only in the journal on b2, >> b2 crashes, something wipes the journal directory and then b2 comes >> back up. > > In this case what happened? > 1. We have WQ = 1 > 2. We had data loss (crash and comeup clean) Ah, maybe this was unclear. I meant, WQ = 2, the fencing is persisted fully on b1, but only onto the journal on b2.
> But yeah, in addition to dataloss we have fencing violation too. > The problem is not just wiped journal dir, but how we recognize the bookie. > Bookie is just recognized by its ip address, not by its incarnation. > Bookie1 at T1 (b1t1) ; and same bookie1 at T2 after bookie format (b1t2) > should be two different bookies, isn;t it? This is something I want to change also for the zk stuff. There should be a uuid generated for the bookie when it is formatted, so that we can distinguish between instances. This uuid should be part of the cookie. Once we detect the uuid for a bookie has changed, all ledgers on that bookie should be checked somehow. -Ivan
