High Availability

This guide is for Apache Hadoop system administrators who want to enable continuous availability by configuring clusters without single points of failure.

Not all Hadoop components currently support highly availability configurations. However, some currently SPOF (single point of failure) components can be configured to restart automatically in the event of a failure (Auto-Restart Configurable, in the table below). Some components support high availability implicitly because they comprise distributed processes (identified with an asterisk (*) in the table). In addition, some components depend on external databases which must also be configured to support high availability.

High Availability Auto-Restart Configurable Components with External Databases
Alert Publisher Hive Metastore Activity Monitor
Cloudera Manager Agent* Impala catalog service Cloudera Navigator Audit Server
Cloudera Manager Server Impala statestore Cloudera Navigator Metadata Server
Data Node* Sentry Service Hive Metastore Server
Event Server Spark Job History Server Oozie Server
Flume* YARN Job History Server Reports Manager
HBase Master Sentry Server
Host Monitor Sqoop Server
Hue (add multiple services, use load balancer)
Impalad* (add multiple services, use load balancer)
Navigator Key Trustee
Node Manager*
Oozie Server
Reports Manager
Resource Manager
Service Monitor
Solr Server*
Zookeeper server*