CHGCLUNODE (Change Cluster Node Entry)

CHGCLUNODE Command syntax diagram

 

Purpose

The Change Cluster Node Entry (CHGCLUNODE) command is used to change cluster membership information for a cluster node entry. The information that can be changed are the cluster interface addresses defined for the node and status of the node. The node entry which is being changed may or may not have Cluster Resource Services started.

You can add, remove, or replace an interface address for the cluster node. The cluster interface address is an IP address that is used by Cluster Resource Services to communicate with other nodes in the cluster. The address is in dotted decimal format.

You can also change the status of a node to Failed. Using this CL command to change the status of a node to Failed provides a way to tell Cluster Resource Services that a node has really failed. There are certain failure conditions that Cluster Resource Services cannot detect as a node failure. Rather, the problem appears to be a communication problem and the cluster has become partitioned. By telling Cluster Resource Services that a node has failed, it makes recovery from the partition state simpler since a backup node from the remaining active cluster nodes can then be assigned as the primary node.

When you change the status of a node to Failed, the role of nodes in the recovery domain for each cluster resource group in the partition may be reordered by assigning the specified node as the last backup. If an exit program is specified for the cluster resource group, it will be called with an action code of Change Node Status. If multiple nodes have failed and their status needs to be changed, the order in which the nodes are changed will affect the final order of the recovery domain's backup nodes in the cluster resource group.

If the node status is changed to Failed and the node was the primary node for a cluster resource group, the first active backup will be reassigned as the new primary node. When this occurs for a device cluster resource group, ownership of the hardware will be moved to the new primary node.

If a problem is detected and the command does not complete successfully, the command can be run again once the problem is corrected. Any cluster resource group that had already had the status of a node changed from Partition to Failed and the recovery domain order changed will not be affected by running this command again.

Warning:

Changing the node status to Failed when, in fact, the node is still active and a true partition has occurred should not be done. Doing so allows a node in each partition to become the primary node for a cluster resource group. When two nodes think they are the primary node, data such as files or data bases could become corrupted if two different nodes are each making independent changes to copies of their files. In addition, the two partitions cannot be merged back together when a node in each partition has been assigned the primary role.

Restrictions

  1. To use this command have *IOSYSCFG authority.

  2. This command cannot be called from a cluster resource group exit program.

  3. This command must be called from a program running on a cluster node with a status of Active.

  4. If the cluster is in a partitioned state, this operation can only be performed within the partition running the command.

  5. Only one cluster interface address can be changed at a time. If the cluster is in partitioned state, the change cluster interface address is only allowed for a node within the same partition.

  6. To change the cluster node status, only a node that has a status of Partition or Failed can be changed and it can only be changed to Failed status.

 

Required Parameters

CLUSTER
Specifies the name of the cluster that contains the node being changed.

cluster-name: Specify the name of the cluster.

NODE
Specifies the node identifier being changed.

node-identifier: Specify the name of the node being changed.

OPTION
Indicates what is being changed.

*ADDIFC: Add an interface address for the specified node.

*RMVIFC: Remove an interface address for the specified node.

*CHGIFC: Replace an interface address for the specified node with a different existing interface address.

*CHGSTS: Change cluster node status to Failed.

OLDINTNETA
Specifies the cluster interface address which is being replaced or removed. The address is in dotted decimal format.

old-interface-address: Specify the cluster interface address to be replaced and removed.

NEWINTNETA
Specifies the cluster interface address which is being added to the node information or replacing an old cluster interface address. The address is in dotted decimal format.

new-interface-address: Specify the cluster interface address which is to be used to communicate with the node.

Example for CHGCLUNODE 

CHGCLUNODE CLUSTER(MYCLUSTER) NODE(NODE01) OPTION(*CHGSTS)

This command changes the status of node NODE01 in cluster MYCLUSTER to Failed.

Error messages for CHGCLUNODE

*ESCAPE Messages

CPF0001
Error found on &1 command.