TCP Discovery URL Format

When multicast discovery is not desirable or possible, you can use pure TCP discovery.

In this case, a number of metaspace members are designated as the “well known” members of the metaspace, and all metaspace members must specify this exact same list of well known members in their discovery URL. At least one of the members listed in the discovery URL must be up and running for the metaspace to exist.

Each well known member is identified by an IP address and a port number. This address and the port are those specified by the well known member's Listen URL (if the member did not specify a Listen URL then the discovery process will use it's default IP address and the first free TCP port it can acquire from the OS (starting at port 50000 and above). See the following section for more information on the Listen URL).

The discovery URL to use well known address TCP discovery has the following format:

tcp://ip1[:port1];ip2[:port2],...

Where any number of ip[:port] well-known addresses can be listed. If no port is specified, the default port number value of 50000 is assumed.

Note: ALL of the metaspace members (including the well-known members themselves) must use the same Discovery URL string when TCP discovery is used.

Note: At least one of the well-known members listed in the discovery URL must be up and running for the metaspace to exist; if none of the well known members listed in the discovery URL is up, other members regularly try to connect and print an advisory message stating that they are waiting for one of the discovery nodes to come up.