Network based Health Check

The HAMon on the secondary node periodically communicates with the primary node using thrift transport-based ping and retrieves state information (thrift sends/receives packets over the internal Ethernet links). If the ping fails, it checks for disk reservation holder status some number of times (150) with intermittent delays [(haMonReleasePollIntervalUs (0.01s)] inserted in between. If the Primary node hasn’t released the reservations within that duration (150 * 0.01 = 1.5sec), then it resorts to a “disk-based” health check.