The FD_SIMPLE protocol is a more tolerant (less false suspicions) protocol based on are-you-alive messages. Each node periodically sends are-you-alive messages to a randomly choosen node and wait for a response. If a response has not been received within a certain timeout time, a counter associated with that node will be incremented. If the counter exceeds a certain value, that node will be suspected. When a response to an are-you-alive message is received, the counter resets to zero. Here is an example configuration for the FD_SIMPLE protocol.
<FD_SIMPLE timeout="2000"
max_missed_hbs="10"/>
The available attributes in the FD_SIMPLE element are listed below.
timeout specifies the timeout (in milliseconds) for the are-you-alive message. If a response is not received within timeout, the counter for the target node is increased.
max_missed_hbs specifies maximum number of are-you-alive messages (i.e., the counter value) a node can miss before it is suspected failure.