The TCPPING protocol takes a set of known members and ping them for discovery. This is essentially a static configuration. It works on top of TCP. Here is an example of the TCPPING configuration element in the JGroups Config element.
<TCPPING timeout="2000"
initial_hosts="hosta[2300],hostb[3400],hostc[4500]"
port_range="3"
num_initial_members="3"
down_thread="false" up_thread="false"/>
The available attributes in the TCPPING element are listed below.
timeout specifies the maximum number of milliseconds to wait for any responses. The default is 3000.
num_initial_members specifies the maximum number of responses to wait for unless timeout has expired. The default is 2.
initial_hosts is a comma-seperated list of addresses (e.g., host1[12345],host2[23456]) for pinging.
port_range specifies the number of consecutive ports to be probed when getting the initial membership, starting with the port specified in the initial_hosts parameter. Given the current values of port_range and initial_hosts above, the TCPPING layer will try to connect to hosta:2300, hosta:2301, hosta:2302, hostb:3400, hostb:3401, hostb:3402, hostc:4500, hostc:4501, hostc:4502. The configuration options allows for multiple nodes on the same host to be pinged.