Sorry, forgot to mention. Version: 3.4.6. Thanks.
2014-11-13 18:11 GMT+01:00 German Blanco <[email protected]>: > Hello, > > which version of Zookeeper are you using? > > On Thu, Nov 13, 2014 at 5:25 PM, Kuba Lekstan <[email protected]> wrote: > > > Hello, > > > > A bit of details: > > We have 5 node cluster, which we use for configuration distrubution and > > monitoring active instances of our applications. Each application creates > > its ephemeral node, so we know which apps are alive, how many of them > there > > is and what they are doing. > > > > The problem had happen at 4th November, first time it was around 4AM, > > second time around 12PM. > > First time it was middle of the night when I got woken up, the support > guys > > told me that something is wrong with config distribution. > > > > First I've checked apps for errors but didn't find anything interesting, > > then I looked at what's in zookeeper (using node-zk-browser). > > I've noticed that there are 3 ephemeral nodes which were created at 1st > nov > > (while the oldest application was started on 3rd nov), I could read its > > data but was not able to delete them - was getting NONODE exception. > > > > I thought wtf - why I cannot delete these nodes, something very bad had > to > > happen with ZK. > > > > So I sshed on the leader and using CLI I tried to read these nodes but I > > was not able to - the leader was telling me that such nodes doesn't > exist. > > After this I started to ssh to the rest of the nodes in cluster and > trying > > to read these nodes. Finally I found the server which did let me read the > > data of these nodes. > > Because of the inconsistency I've decided to restart it. Restart did > help, > > everything went back to normal state. The ephemeral nodes disappeared. > > > > Similar situation had happen at 12PM but this time I had a lot more time > to > > look what is wrong. Second time the problem was about 3 ephemeral nodes > > which were created at 1st now (again?). This time I dig a bit deeper and > > look into logs and 4 letter commands - but could not find anything > > interesting except the all these 3 nodes were created under different > > sessionids but zk had no hosts connected under this sessionids. > > Solution was similar to the one from 4AM but this time I've delete all > > files in ZK data directory. > > > > Oddly enough the problem happened twice on the same ZK node, the final > > solution was to clear ZK data directory. After clearing the directory the > > problem didn't happen again. > > > > I tried to look for solution/similar problems, I found the posts where > > people were complaining about ephemeral nodes not being removed after > > client session gets closed. But I was not able to find posts about ZK not > > being consistent. > > > > What do you think about this? Can we do something to fix this? > > > > Sorry for my english, I was doing my best. :) > > > > Thanks, Kuba. > > >
