Performance is one of the most interesting characteristics of an HBase cluster's behavior. It is a challenging operation for administrators, because performance tuning requires deep understanding of not only HBase but also of Hadoop, Java Virtual Machine Garbage Collection (JVM GC), and important tuning parameters of an operating system.
The structure of a typical HBase cluster is shown in the following diagram:
There are several components in the cluster—the ZooKeeper cluster, the HBase master node, region servers, the Hadoop Distributed File System (HDFS) and the HBase client.
The ZooKeeper cluster acts as a coordination service for the entire HBase cluster, handling master selection, root region server lookup, node registration, and so on. The master node does not do heavy tasks. Its job includes region allocation and failover, log splitting, and load balancing. Region servers hold the actual regions; they handle I/O requests to the hosting regions, flush the in-memory...
