Cluster problems

There are several reasons why you might experience problems and unexpected behavior when you configure and use clusters of Eclipse Amlen servers.

Do none, or only some, of your servers connect to the cluster after you enable the cluster?

If the status of your cluster is similar to the following output:

"Cluster": {
    "Status": "Active",
    "Name": "MyCluster",
    "Enabled": true,
    "ConnectedServers": 0,
    "DisconnectedServers": 0
  }

where the values of "ConnectedServers" and "DisconnectedServers" are zero, or lower than you expect, it is possible that the cluster name that you are specifying is different on some of the cluster members. Verify that you are using the same cluster name on all the cluster members.

Are some of your servers unable to locate each other in the cluster?

Servers can locate each by using one or both of 2 methods:

Multicast discovery.
If you are using only multicast discovery, ensure that your environment supports multicast. You can use the omping tool to test multicast connectivity between servers in a cluster. For more information about using the omping tool, see Using omping to test multicast connectivity in clusters.
Use of a discovery server list, which is a comma-separated list of servers in the cluster.
If you are using a discovery server list, ensure that all of the following conditions are met:
- All of your servers are visible to each other on the network. All servers in the cluster must have a network route to all other servers in the cluster.
- At least one of the servers in the discovery server list is active.
- You are specifying the correct port number. Ensure that you specify the same port number that you specify for the cluster control port.