Yarn vs Zookeeper: What are the differences?

# Key Differences between Yarn and Zookeeper

Yarn and Zookeeper are both essential tools in the world of Big Data, but they serve different purposes and have distinct features that set them apart. 

1. **Resource Management**: Yarn is primarily responsible for resource management in Hadoop clusters, efficiently allocating resources among different applications based on their requirements. In contrast, Zookeeper is a centralized service for maintaining configuration information and providing distributed synchronization across a cluster.

2. **Data Storage**: While Yarn focuses on resource management, Zookeeper is primarily used for storing small amounts of data such as configuration settings, status information, and so on. Zookeeper provides a hierarchical namespace for organizing this data efficiently.

3. **Consistency Guarantees**: Zookeeper provides strong consistency guarantees, ensuring that all clients see the same view of the data at any given time. This makes it a suitable choice for coordination tasks requiring strict synchronization. In comparison, Yarn focuses on resource allocation and scheduling, without providing strong consistency guarantees.

4. **Fault Tolerance**: Yarn comes with built-in fault tolerance mechanisms that enable it to recover from failures gracefully. It can handle node failures, network partitions, and other issues without impacting the overall operation of the cluster. Zookeeper also offers robust fault tolerance features, ensuring high availability and data integrity in distributed environments.

5. **Use Cases**: Yarn is typically used for running distributed applications, batch processing, and real-time processing tasks in Hadoop clusters. On the other hand, Zookeeper is more suited for distributed coordination, leader election, configuration management, and distributed locking scenarios where consistency and reliability are critical.

6. **Scalability**: Both Yarn and Zookeeper are designed to scale horizontally to accommodate growing workloads and data volumes. However, the scalability characteristics of each tool differ slightly based on their intended use cases and underlying architecture.

In Summary, Yarn and Zookeeper play distinct roles in the realm of Big Data, with Yarn focusing on resource management and scheduling while Zookeeper excels in distributed coordination and maintaining consistent configuration data across clusters.