A Connection and a ZK session are two different things. The ZK master keeps track of a client session validity. When a client connection gets interrupted, its associated session goes into Disconnected state, after a while it will be Expired, but if a new connection is established before the timeout then the session will be Connected again.
see http://zookeeper.apache.org/doc/trunk/zookeeperProgrammers.html#ch_zkSessions Example state transitions for an expired session as seen by the expired session's watcher: 1. 'connected' : session is established and client is communicating with cluster (client/server communication is operating properly) 2. .... client is partitioned from the cluster 3. 'disconnected' : client has lost connectivity with the cluster 4. .... time elapses, after 'timeout' period the cluster expires the session, nothing is seen by client as it is disconnected from cluster 5. .... time elapses, the client regains network level connectivity with the cluster 6. 'expired' : eventually the client reconnects to the cluster, it is then notified of the expiration On Wed, Feb 17, 2016 at 11:38 AM Christian Posta <christian.po...@gmail.com> wrote: > I believe so. Happy to be corrected. > > On Wed, Feb 17, 2016 at 12:31 PM, Joe San <codeintheo...@gmail.com> wrote: > > > So if I use the High Level Consumer API, using the ConsumerConnector, I > get > > this automatic zookeeper connection for free? > > > > On Wed, Feb 17, 2016 at 8:25 PM, Christian Posta < > > christian.po...@gmail.com> > > wrote: > > > > > i believe reconnect is handled automatically by the client... is that > > what > > > you're asking > > > peek here to see how it does that and when: > > > > > > > > > > > > https://github.com/apache/zookeeper/blob/trunk/src/java/main/org/apache/zookeeper/ClientCnxn.java#L1153 > > > > > > On Wed, Feb 17, 2016 at 12:14 PM, Joe San <codeintheo...@gmail.com> > > wrote: > > > > > > > It is all pretty strange. Here is what I see in my logs as soon as I > > > > voluntarily shutdown Zookeeper! > > > > > > > > java.net.ConnectException: Connection refused > > > > at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) > > > ~[na:1.8.0_60] > > > > at > > sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) > > > > ~[na:1.8.0_60] > > > > at > > > > > > > > > > > > > > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361) > > > > ~[zookeeper-3.4.6.jar:3.4.6-1569965] > > > > at > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1081) > > > > ~[zookeeper-3.4.6.jar:3.4.6-1569965] > > > > 20160217-20:12:44.960+0100 > > > > [sally-kafka-consumer-akka.actor.default-dispatcher-4-SendThread( > > > > 127.0.0.1:2181)] INFO org.apache.zookeeper.ClientCnxn - Opening > > socket > > > > connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to > > > > authenticate using SASL (unknown error) > > > > 20160217-20:12:44.960+0100 > > > > [sally-kafka-consumer-akka.actor.default-dispatcher-4-SendThread( > > > > 127.0.0.1:2181)] WARN org.apache.zookeeper.ClientCnxn - Session > > > > 0x152ea19656b005c for server null, unexpected error, closing socket > > > > connection and attempting reconnect > > > > java.net.ConnectException: Connection refused > > > > at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) > > > ~[na:1.8.0_60] > > > > at > > sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) > > > > ~[na:1.8.0_60] > > > > at > > > > > > > > > > > > > > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361) > > > > ~[zookeeper-3.4.6.jar:3.4.6-1569965] > > > > at > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1081) > > > > ~[zookeeper-3.4.6.jar:3.4.6-1569965] > > > > > > > > It just keep repeating trying to reconnect for ever! So I just wanted > > to > > > > know which property from my setting in my email above is responsible > > for > > > > this auto reconnect mechanism? > > > > > > > > On Wed, Feb 17, 2016 at 8:04 PM, Christian Posta < > > > > christian.po...@gmail.com> > > > > wrote: > > > > > > > > > Yep, assuming you haven't completely partitioned that client from > the > > > > > cluster, ZK should automatically try to connect/reconnect to other > > > peers > > > > in > > > > > the server list. Otherwise, it's as Alexis said -- your session > would > > > > > expire; you'd have to recreate the session once you have > connectivity > > > > > > > > > > On Wed, Feb 17, 2016 at 2:30 AM, Alexis Midon < > > > > > alexis.mi...@airbnb.com.invalid> wrote: > > > > > > > > > > > By "re-connect", I'm assuming that the ZK session is expired, not > > > > > > disconnected. > > > > > > For details see > > > > > > > > > > > > > > > > > > > > > > > > > > > http://zookeeper.apache.org/doc/trunk/zookeeperProgrammers.html#ch_zkSessions > > > > > > > > > > > > In that case, the high level consumer is basically dead, and the > > > > > > application should create a new instance of it. > > > > > > > > > > > > > > > > > > On Mon, Feb 15, 2016 at 12:22 PM Joe San < > codeintheo...@gmail.com> > > > > > wrote: > > > > > > > > > > > > > Any ideas as to which property should I set to enable Zookeeper > > > > > > > re-connection? I have the following properties defined for my > > > > consumer > > > > > > > (High Level Consumer API). Is this enough for a automatic > > Zookeeper > > > > > > > re-connect? > > > > > > > > > > > > > > val props = new Properties() > > > > > > > props.put("zookeeper.connect", zookeeper) > > > > > > > props.put("group.id", groupId) > > > > > > > props.put("auto.commit.enabled", "false") > > > > > > > // this timeout is needed so that we do not block on the > stream! > > > > > > > props.put("consumer.timeout.ms", "1") > > > > > > > props.put("zookeeper.sync.time.ms", "200") > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > *Christian Posta* > > > > > twitter: @christianposta > > > > > http://www.christianposta.com/blog > > > > > http://fabric8.io > > > > > > > > > > > > > > > > > > > > > -- > > > *Christian Posta* > > > twitter: @christianposta > > > http://www.christianposta.com/blog > > > http://fabric8.io > > > > > > > > > -- > *Christian Posta* > twitter: @christianposta > http://www.christianposta.com/blog > http://fabric8.io >
