Apache ZooKeeper Essentials

The ZooKeeper data model

As defined by the ZooKeeper wiki, ZooKeeper allows distributed processes to coordinate with each other through a shared hierarchical namespace of data registers. The namespace looks quite similar to a Unix filesystem. The data registers are known as znodes in the ZooKeeper nomenclature. You can see examples of znodes in the following image:

A ZooKeeper's hierarchical namespace

Here, you can see that znodes are organized hierarchically, much like a tree, as a standard filesystem. Some important points to take note of are as follows:

• The root node has one child znode called /zoo, which in turn has three znodes.
• Every znode in ...