Configuring a ZooKeeper ensemble
In this section, we will look at configuration options that are mostly used with an ensemble of ZooKeeper servers. A ZooKeeper ensemble or cluster of replicated ZooKeeper servers should be configured optimally to avoid scenarios such as split-brain. A split-brain scenario might happen due to network portioning where two different servers of the same ensemble might pose as leaders and cause inconsistencies.
The following configuration options are available with an ensemble of ZooKeeper servers:
electionAlg: This option is used to choose a leader in a ZooKeeper ensemble. A value of 0 corresponds to the original UDP-based version, 1 corresponds to the non-authenticated UDP-based version of fast leader election, 2 corresponds to the authenticated UDP-based version of fast leader election, and 3 corresponds to the TCP-based version of fast leader election. Currently, algorithm 3 is the default. The implementations of leader election 0, 1, and 2 are now deprecated...
