ZooKeeper acts as a coordination service that provides flexible and robust synchronization within distributed systems. ZooKeeper forms an integral part of Kafka as it keeps track of the status of the Kafka cluster nodes and the Kafka topics and partitions. The leader election between the Kafka brokers is also performed by using ZooKeeper when the leader node fails.
Apache ZooKeeper is already packaged with the ZENworks 2020 build. When the build is deployed on the first Primary Server, ZooKeeper is automatically enabled in the zone. However, you can expand the ZooKeeper cluster as per your scalability requirements and to provide fault tolerance.
NOTE:Besides Vertica, other services in ZENworks require the ZooKeeper services to be up and running at all times. Therefore, even if you do not have Vertica configured in your zone, ZooKeeper should always be active. You also need to ensure that the firewall allows client connections from other Primary Servers like those in the DMZ, to the ZooKeeper services on port 6789. For more information, see Firewall Issues.
For more information on adding additional servers to the ZooKeeper cluster, see Managing Vertica, Kafka and ZooKeeper.
For more information on monitoring the ZooKeeper services, see Monitoring Diagnostics.
NOTE:If vulnerabilities are reported while running the Qualys scan on a Primary Server that has ZooKeeper configured on it, then to resolve the issue follow the procedure documented in TID 7024819.