Anand, in your lab are you able to replicate this with 3.4.8 or 3.4.9? On Mon, Oct 10, 2016 at 10:15 AM, Anand Parthasarathy < [email protected]> wrote:
> Folks, > > Any insight into this or any workarounds that you can think of to mitigate > against this issue? We have isolated it to a test setup, where we are able > to reproduce this somewhat consistently if we keep a node powered off. > > Thanks, > Anand. > > On Sat, Oct 8, 2016 at 10:05 AM, Anand Parthasarathy < > [email protected]> wrote: > > > Hi Flavio, > > > > I have attached the logs from node 1 and node 3. Node 2 was powered off > > around 10-03 12:36. Leader election kept going until 10-03 15:57:16 when > it > > finally converged. > > > > Thanks, > > Anand. > > > > On Sat, Oct 8, 2016 at 7:55 AM, Flavio Junqueira <[email protected]> wrote: > > > >> Hi Anand, > >> > >> I don't understand whether 1 and 3 were able or even trying to connect > to > >> each other. They should be able to elect a leader between them and make > >> progress. You might want to upload logs and let us know. > >> > >> -Flavio > >> > >> > On 08 Oct 2016, at 02:11, Anand Parthasarathy < > [email protected]> > >> wrote: > >> > > >> > Hi, > >> > > >> > We are currently using zookeeper 3.4.6 version and use a 3 node > >> solution in > >> > our system. We see that occasionally, when a node is powered off (in > >> this > >> > instance, it was actually a leader node), the remaining two nodes do > not > >> > form a quorum for a really long time. Looking at the logs, it appears > >> the > >> > sequence is as follows: > >> > - Node 2 is the zookeeper leader > >> > - Node 2 is powered off > >> > - Node 1 and Node 3 recognize and start the election > >> > - Node 3 times out after initLimit * tickTime with "Timeout while > >> waiting > >> > for quorum" for Round N > >> > - Node 1 times out after initLimit * tickTime with "Exception while > >> trying > >> > to follow leader" for Round N+1 at the same time. > >> > - And the process continues where N is sequentially incrementing. > >> > - This happens for a long time. > >> > - In one instance, we used tickTime=5000 and initLimit=20 and it took > >> > around 3.5 hours to converge. > >> > - In a given round, Node 1 will try connecting to Node 2, gets > >> connection > >> > refused waits for notification timeout which increases by 2 every > >> iteration > >> > until it hits the initLimit. Connection Refused is because the node 2 > >> comes > >> > up after reboot, but zookeeper process is not started (due to a > >> different > >> > failure). > >> > > >> > It looks similar to ZOOKEEPER-2164 but there it is a connection > timeout > >> > where Node 2 is not reachable. > >> > > >> > Could you pls. share if you have seen this issue and if so, what is > the > >> > workaround that can be employed in 3.4.6. > >> > > >> > Thanks, > >> > Anand. > >> > >> > > >
