Difference between ensemble and quorum in zookeeper

Question

Hi,

I am new to zookeeper, but I came across the terms ensemble and quorum in Zookeeper. Can anyone please let me know the difference in this?

Answer 1

Hey,

When you want to have high availability in zookeeper server you use multiple zookeeper servers to create an ensemble. Basically, Zookeeper has a master-slave architecture. In an ensemble, there will be one master and the rest will be the slaves. If the master fails one of the salves will act as a master.

The sequence in which a master is called a quorum. When you create an ensemble, zookeeper internally creates a sequence ID for the slave servers. When the main master fails, it will check the next sequence ID to create a new master. This concept of quorum also used while creating nodes in zookeeper.