Amazon EMR announces Support for Multiple Master nodes to enable High Availability for EMR applications in all supported regions for Amazon EMR, including Amazon Web Services China (Beijing) Region operated by Sinnet, and Amazon Web Services China (Ningxia) Region, operated by NWCD

You can now launch an EMR cluster with three master nodes and support high availability of applications like YARN Resource Manager, HDFS Name Node, Spark, Hive, and Ganglia. Amazon EMR automatically fails over to a standby master node if the primary master node fails or if critical processes, like Resource Manager or Name Node, crash. 

Since the master node is no longer a potential single point of failure with this feature, you can run your long-lived EMR clusters without interruption. In the event of a failover, Amazon EMR automatically replaces the failed master node with a new master node with the same configuration and boot-strap actions. 

This feature is now available from EMR release 5.23.0 in all supported regions for Amazon EMR, including Amazon Web Services China (Beijing) Region operated by Sinnet, and Amazon Web Services China (Ningxia) Region, operated by NWCD