What is the role of ZooKeeper in HBase?

ZooKeeper plays a critical role as a coordination service in HBase. Specifically, ZooKeeper is mainly used in HBase for the following purposes:

1. Coordinating distributed services: HBase is a distributed database system where its various nodes require coordination and communication. ZooKeeper acts as a coordinator, assisting the different HBase nodes with distributed coordination and management.
2. Metadata storage: HBase utilizes ZooKeeper to store and manage crucial metadata information, such as table structure and region distribution. These metadata are vital for the proper functioning of HBase, and their management by ZooKeeper ensures consistency and reliability.
3. Leader election: In an HBase cluster, ZooKeeper also assists in conducting leader elections to ensure high availability of nodes within the cluster. With the help of ZooKeeper, HBase can ensure normal operation in cases of node failures or network partitions.

In summary, ZooKeeper plays a role in coordinating and leader election within HBase, helping HBase clusters achieve distributed coordination, metadata management, and high availability assurance.