Putting a Node into Maintenance Mode

Before putting a node into maintenance mode, make sure that:
  • All copies of CLDB volume exists 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.
    Note: A node that is running both the CLDB and MapR Filesystem services cannot be put into maintenance mode. You can shut down the CLDB service on the node as long as it is a secondary CLDB node or High Availability for CLDB is enabled.
  • All running processing tasks (such as NodeManager, Spark, etc.) that depend on 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, follow this process:
  1. From a terminal, issue the node maintenance command:
    maprcli node maintenance -nodes <IP|hostname> -timeoutminutes <minutes>

    When running 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 this node's data 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, MapR Filesystem will be shut down on that node so that any client(s) accessing containers on this node will get appropriate error and retry other container copies.
  2. Stop warden on the node.