To ensure that a multi-node cluster remains available, configure and enable High Availability. The configuration process for High Availability includes defining locations and names of hosts in a cluster that are available to act as journal nodes, and a standby name node in the event that the primary namenode fails. To configure namenode High Availability, select the HA components
tab. Define the locations and names of hosts in a cluster that are available to act as JournalNodes and the Resource Manager. Specify a standby namenode in case the primary namenode fails.
To enable High Availability, you must also run several commands while starting cluster services.
Configuration Property Name | Description | Example Value | Mandatory/Optional |
---|---|---|---|
Enable HA | Whether to deploy a highly available NameNode or not. | yes or no | Optional |
NN Journal Node Hosts | A comma-separated list of FQDN for cluster nodes that will run the JournalNode processes. | journalnode1.acme.com, journalnode2.acme.com, journalnode3.acme.com | Optional |
NN HA Cluster Name | This name is used for both configuration and authority component of absolute HDFS paths in the cluster. | hdp2-ha | Optional |
NN Journal Node Edits Directory | This is the absolute path on the JournalNode machines where the edits and other local state used by the JournalNodes (JNs) are stored. You can only use a single path for this configuration. | d:\hadoop\journal | Optional |
NN Standby Host | The host for the standby NameNode. | STANDBY_NAMENODE. acme.com | Optional |
RM HA Cluster Name | A logical name for the Resource Manager cluster. | HA Resource Manager | Optional |
RM Standby Host | The FQDN of the standby resource manager host. | rm-standby-host.acme.com | Optional |
Enable Knox HA | Enable Knox High Availability mode | Selected | Optional |
Enable Oozie HA | Enable Oozie High Availability mode | Selected | Optional |
Oozie server hosts | A comma-separated list of FQDN for cluster nodes that will run Oozie servers. | ooziehost1.acme.com, ooziehost2.acme.com | Optional |
Oozie loadbalancer url | URL for Oozie Load Balancer | http://oozie.lb.com:11000/oozie | Optional |