What is Zookeeper What is the purpose of Zookeeper in Hadoop Ecosystem

The answer for what is zookeeper hadoop? First of all, let me show you what a hadoop ecosystem looks like.

In the image below you can see the tools that are present in a hadoop ecosystem.

Now talking about Zookeeper, Apache Zookeeper is a coordination service for distributed applications that enables synchronization across a cluster.

So, in the case of Hadoop, ZooKeeper will help you with coordination between Hadoop nodes.

For example, it makes it easier to:

• Manage configuration across nodes. If you have dozens or hundreds of nodes, it becomes hard to keep configuration in sync across nodes and quickly make changes. ZooKeeper helps you quickly push configuration changes.
  
• Implement reliable messaging. With ZooKeeper, you can easily implement a producer/consumer queue that guarantees delivery, even if some consumers or even one of the ZooKeeper servers fails.
  
• Implement redundant services. With ZooKeeper, a group of identical nodes (e.g. database servers) can elect a leader/master and let ZooKeeper refer all clients to that master server. If the master fails, ZooKeeper will assign a new leader and notify all clients.
  
• Synchronize process execution. With ZooKeeper, multiple nodes can coordinate the start and end of a process or calculation. This ensures that any follow-up processing is done only after all nodes have finished their calculations.