List of ZooKeeper nodes could be periodically updated from Exhibitor
Since we know that each Exhibitor accompanies one ZooKeeper node, list
of Exhibitor nodes also maintained. Exhibitor assumes that all ZooKeeper
nodes are using the same client port, 2181. The same assumption is valid
for Exhibitor, it should always listen on the same port on all nodes.
Original list of Exhibitor nodes is cached and used as a fallback when
it failed ito query information with using maintained list.
In case if one member of a cluster is not available it will retry with
another one and fetch the new cluster configuration. Default timeout for
all requests to etcd is 5 seconds.
Initial cluster configuration can be resolved through:
1) /v2/members call on one of the cluster members on a client port
2) when it is possible to resolve hostname into multiple ip's it will
iterate through list and try to perform action from 1)
3) If there is discovery_srv defined in etcd section of config file it
will resolve peer addresses of all cluster members and will fetch
cluster configuration with using peer protocol by doing /members call on
a peer port
Alexander Kukushkin