Replacing a Data Node

This procedure is for replacing a data node in a High Availability cluster. For more information, see High Availability.

Limitations

  • If the existing node is not healthy, you must use the --force flag. This will allow the command to be run but will not delete the TOS data.

  • The new node cannot already be a node in the cluster.

  • The primary data node cannot be replaced using this command. You must first elect a different data node for the role, using sudo tos cluster set-primary.

Cluster and node status and health can be seen using sudo tos status.

Procedure

  1. On the primary data node:

    [primary data node]# sudo tos cluster node replace <OLD_NODE> [--force] 
    sudo tos cluster node replace <OLD_NODE> [--force]

    Parameters

    Parameter

    Description

    Required/Optional

    <OLD NODE>

    Name of the node you want to remove, as seen in the output of sudo tos cluster node list.

    Required

    --force

    Only use this flag when the node you want to remove is not in a healthy state. 

    Optional

    On completion, one or two new command strings will appear in the output. The second command string will appear only if the original node was in a healthy state, i.e.  -force was not used.

  2. Copy/paste the first string and run it on the new node.

  3. If a second string appeared in the output from the command that you ran on the primary data node, copy/paste this string and run it on the old node.

  4. Verify that the nodes in the cluster are what you expected, by running sudo tos cluster node list on the primary data node.