also, if you want, you can enable read-only mode in the ZooKeeper server. Read-only mode allows client sessions to connect to the server even when the server might be partitioned from the quorum. In this mode the clients can still read values from the ZK service, but will be unable to write values and see changes from other clients. Also beside enabling this on server-side, you have to allow this on the client side as well when you initiate the connection. By default the Read-only mode is disabled and ZooKeeper behaves as Chris described.
Kind regards, Mate On Tue, Apr 28, 2020 at 6:27 PM Chris T. <[email protected]> wrote: > 1: It will close the client port and will remain unavailable for clients > until it can form or join a quorum (majority). > 2: No, see above. > 3+4: They will keep trying to connect to the Zookeeper servers in the > connection string until they find one that works. The exact messages you > get depend on the client application or framework you are using. For > example Apache Curator framework or the internal client implementations of > SOLR or KAFKA all have different behaviour and messages messages. Something > like Connection State Lost, Client Connection timed out, Attempting > reconnect etc... > > Regards, > > Chris > > > On Tue, Apr 28, 2020 at 5:47 PM Vincent Ngan <[email protected]> > wrote: > > > Hi, > > > > I would like to know what will happen to ZooKeeper servers and the > clients > > connected to them when a network segmentation occurs. > > > > Supposing a network segmentation happens. One of the ZK servers > > looses contact with all the other ZK servers. This ZK server is still but > > it should know that it is not among the majority of a quorum. Then, > > > > 1. What will happen to this isolated ZK server? > > 2. Will it still function and serve client requests? > > 3. If there are clients also located in the same isolated segment and > > are currently connected to this ZK server, what will happen to these > > clients? > > 4. What errors code and messages will these clients detect? > > > > Best regards, > > VN > > >
