Under the Hood: Hadoop Distributed Filesystem reliability with Namenode and Avatarnode

What this post added

This post details the development and open-sourcing of Avatarnode, a highly available Namenode solution for Hadoop Distributed Filesystem (HDFS). It addresses the single point of failure (SPOF) issue with the traditional Namenode, which was responsible for 41% of HDFS-related incidents in Facebook's Data Warehouse. Avatarnode uses ZooKeeper to manage failover between a Primary and Standby Namenode, ensuring continuous operation and reducing planned downtime. The post also highlights the significant load on the Namenode in large-scale HDFS deployments and the impact of Namenode unavailability on cluster functionality.