The nhcmmqualif command calls the cmm_member_seizequalif(3CMM)
function to qualify the current node as master-eligible and start a new master
election. This call is only successful if there is no active master node in
the cluster and if the current node is master-eligible. If this call is not
successful, a 255 exit code is returned. If this call is
successful, this command forces the qualification of the current node so that
this node becomes the master node. Use this command when no node is qualified
to become master. Note that an unsynchronized node will only be elected as
master node if its former role was master.
The nhcmmqualif command can only be called from a
master-eligible node. This call has one of two outcomes for this node; either
the node becomes master, or it reverts to the qualification level it had prior
to the nhcmmqualif call.
If you attempt to call nhcmmqualif from a node that
is not master-eligible, the command exits with a 255 exit
code. If a master is already running when nhcmmqualif is
called, the command exits with a 255 exit code. If nhcmmqualif provokes a change in the status of a peer node, a notification
is sent by the CMM API.
This section contains examples of how to use the nhcmmqualif command.
Example 1. To Force Qualification of a Master-Eligible Node
When there is no current master node in the cluster and no node is qualified
to be the master node:
The master-eligible node on which you ran the nhcmmqualif
command is temporarily qualified as the master node.
If you run nhcmmqualif on a master-eligible node
in a cluster with a valid master node, the node is not forced to become master
and the 255 exit status is produced.
Example 2. To Requalify a Node Synchronously
Use the timeout option to requalify a node synchronously.