Legacy ActiveSpaces Cluster Discover URL
When a cluster starts up, and also when new members join a cluster, a discovery process enables the members to discover each other.
The discover URL specifies how an engine (node) listens for discovery requests from nodes attempting to join the cluster. After the discovery is complete, the members communicate internally using a listen URL (seeLegacy ActiveSpaces Cluster Listen URL).
Two types of discovery are available:
- Multicast discovery (PGM), see Multicast (PGM) Cluster Member Discovery.
- Unicast discovery (TCP), also known as "well-known address" discovery, see Unicast (Well-Known Address) Cluster Member Discovery.
A TIBCO BusinessEvents engine is a node in the metaspace.
If No Other Cluster Members are Started
If a newly started node does not discover any running cluster nodes, the behavior is different depending on the type of discovery used:
- If multicast discovery is used, the newly started node becomes the first node of a newly started cluster.
- If unicast (well-known-address) discovery is used there are two cases:
- If the listenURL of the newly started node is not in the discover URL’s list then it continues to wait for other well-known nodes to start, and a warning is written to the console while it waits.
- If the listenURL of the newly started node is in the discover URL’s list, then it becomes the first node of a newly started cluster.