Putting a Node into Maintenance Mode

Describes how to put a node into maintainance mode.

Before putting a node into maintenance mode, ensure that:
  • All copies of the CLDB volume exist if the node is a CLDB node. You can shut down the CLDB service on a node only if the CLDB is a slave CLDB or if high availability for CLDB is enabled.

    You cannot put a node that is running both the CLDB and MapR Filesystem services into maintenance mode. You can shut down the CLDB service on the node as long as it is a secondary CLDB node or if you have enabled High Availability for CLDB.

  • All running processing tasks (such as NodeManager, Spark, for example) that depend on the MapR Filesystem have been stopped.
Warning: Do not put a node under maintenance if there are any volume under-replicated alarms because doing so may make some data completely offline.
To put a node into maintenance mode, perform the following actions:
  1. From a terminal, issue the node maintenance command:
    maprcli node maintenance -nodes <IP|hostname> -timeoutminutes <minutes>

    When you run this command, specify a timeout (in minutes) long enough for you to perform necessary maintenance on the node.

    Note: For the duration of the timeout, the cluster's CLDB does not consider the data of this node as lost and does not trigger a resync of the data on this node. However, if a node is put under maintenance for more than 5 minutes, the MapR Filesystem is shut down on that node so that clients who access containers on this node receive the appropriate error and retry other container copies. This value of 5 minutes is hardcoded and cannot be changed.
  2. Stop warden on the node.