What is the purpose of using Zookeeper in Storm?

Zookeeper is used in the storm for coordination of cluster. It's not the duty of the zookeeper to pass the messages, which makes the load on it lighter. Zookeeper clusters of a single node are good and can do most tasks. But for deploying storm clusters that are large, it might need larger zookeeper clusters. Zookeeper should be run very carefully for the reason being the process will get excited if the zookeeper encounters an error case.