When a GAB client on a node comes up or goes down, the entire cluster needs to be aware of the change in "membership" for that port. After GAB on all the nodes agrees about this, the message is displayed. When a cluster node is started or brought down, all GAB clients on the node also start or go down, causing this message to appear for each port. Also, if the network connection to a node is lost, GAB on each node logs this messageafter the cluster handles the situation. All alive nodes of the cluster where GAB is configured shows these messages almost simultaneously, unless some nodes are heavily loaded.
If the administrator started or brought down a cluster node or a GAB client, or disconnected all the network links of one or more nodes, these messages are expected. If these messages appear unexpectedly, do the following:
The corresponding GAB client might have started accidentally. The "new" node might have been busy when the GAB client started and just recovered from the scenario. Collect commslog information immediately using the getcomms command. Also collect any logs and traces of the GAB client.