# ApiEnableNnHaArguments Data Model

Arguments used for Enable NameNode High Availability command.

Properties
name | data type | description
--- | --- | ---
activeNnName | string | Name of the NameNode role that is going to be made Highly Available.
standbyNnName | string | Name of the new Standby NameNode role that will be created during the command (Optional).
standbyNnHostId | string | Id of the host on which new Standby NameNode will be created.
standbyNameDirList | array of string | List of directories for the new Standby NameNode. If not provided then it will use same dirs as Active NameNode.
nameservice | string | Nameservice to be used while enabling Highly Available. It must be specified if Active NameNode isn't configured with it. If Active NameNode is already configured, then this need not be specified. However, if it is still specified, it must match the existing config for the Active NameNode.
qjName | string | Name of the journal located on each JournalNodes' filesystem. This can be optionally provided if the config hasn't already been set for the Active NameNode. If this isn't provided and Active NameNode doesn't also have the config, then nameservice is used by default. If Active NameNode already has this configured, then it much match the existing config.
activeFcName | string | Name of the FailoverController role to be created on Active NameNode's host (Optional).
standbyFcName | string | Name of the FailoverController role to be created on Standby NameNode's host (Optional).
zkServiceName | string | Name of the ZooKeeper service to be used for Auto-Failover. This MUST be provided if HDFS doesn't have a ZooKeeper dependency. If the dependency is already set, then this should be the name of the same ZooKeeper service, but can also be omitted in that case.
jns | array of ApiJournalNodeArguments | Arguments for the JournalNodes to be created during the command. Must be provided only if JournalNodes don't exist already in HDFS.
forceInitZNode | boolean | Boolean indicating if the ZNode should be force initialized if it is already present. Useful while re-enabling High Availability. (Default: TRUE)
clearExistingStandbyNameDirs | boolean | Boolean indicating if the existing name directories for Standby NameNode should be cleared during the workflow. Useful while re-enabling High Availability. (Default: TRUE)
clearExistingJnEditsDir | boolean | Boolean indicating if the existing edits directories for the JournalNodes for the specified nameservice should be cleared during the workflow. Useful while re-enabling High Availability. (Default: TRUE)

Example

    {
      "activeNnName" : "...",
      "standbyNnName" : "...",
      "standbyNnHostId" : "...",
      "standbyNameDirList" : [ "...", "..." ],
      "nameservice" : "...",
      "qjName" : "...",
      "activeFcName" : "...",
      "standbyFcName" : "...",
      "zkServiceName" : "...",
      "jns" : [ {
        "jnName" : "...",
        "jnHostId" : "...",
        "jnEditsDir" : "..."
      }, {
        "jnName" : "...",
        "jnHostId" : "...",
        "jnEditsDir" : "..."
      } ],
      "forceInitZNode" : true,
      "clearExistingStandbyNameDirs" : true,
      "clearExistingJnEditsDir" : true
    }