ZooKeeper acts as a coordination service that provides flexible and robust synchronization within distributed systems. Apache ZooKeeper is already packaged with the ZENworks 2020 build. When you upgrade or install the ZENworks 2020 or a later release version on your first Primary Server, the ZooKeeper role is automatically enabled on this server.
However, if the Primary Server that is within the DMZ is unable to access the ZooKeeper service within the corporate network, then you need to manually open the port 6789 in the corporate firewall.
For more information on the ZooKeeper ports, see ZENworks TCP and UDP Ports.
You can expand the ZooKeeper cluster as per your scalability requirements and to provide fault tolerance. To expand the ZooKeeper cluster and to maintain the cluster you need to execute a set of ZMAN commands.