Suspend and Resume Nodes

This section explains how to suspend and resume nodes in a cluster.

The suspended node state indicates that the node has been intentionally taken offline, for example for maintenance.

Prerequisites

There are no prerequisites for this procedure.

Procedure

This procedure is carried out using ConfD.

The following examples use ConfD through the command-line tool confd_client, which is available on all database nodes. For more information, see ConfD.

Connect to COS

Connect to EXAClusterOS (COS) using c4 connect -t <DEPLOYMENT>[.<NODE>]/cos. For example:

c4 connect -t 1/cos

In most cases it does not matter on which node you access ConfD. If you do not specify a node, c4 will connect to the first active node in the deployment. The command prompt in COS indicates which node you are connected to: 

[root@n11 ~]#

For more information about how to use c4 connect, see How to use c4.

Suspend a node

To suspend a node, use the ConfD command node_suspend with the node ID. For example, to suspend node 12 in the current deployment:

confd_client node_suspend nid: 12

Resume a node

Starting up a node will automatically unsuspend it. You can also manually unsuspend a node using the ConfD job node_resume. For example:

confd_client node_resume nid: 12