When checkmetod is "pid", this means pid file path.
The default value is pid_file_name setting in pgpool.conf.
-When checkmetod is "pcp", this means parameters for pcp_nod_count command.
+When checkmetod is "pcp", this means parameters for pcp_node_count command.
The default value is "10 localhost 9898 postgres pass".
"-w -h localhost -p 9898" is a good idea for 3.5.x and later version,
for the response 'authentication failed' is considered success.