When I strace the watchdog process on the server I get the following repeated over and over:
select(1, [0], NULL, NULL, {0, 0}) = 0 (Timeout)
gettimeofday({1474997332, 879937}, NULL) = 0
gettimeofday({1474997332, 880212}, NULL) = 0
gettimeofday({1474997332, 880425}, NULL) = 0
gettimeofday({1474997332, 880633}, NULL) = 0
select(1, [0], NULL, NULL, {0, 347405}) = 0 (Timeout)
gettimeofday({1474997333, 230992}, NULL) = 0
gettimeofday({1474997333, 232292}, NULL) = 0
gettimeofday({1474997333, 233713}, NULL) = 0
gettimeofday({1474997333, 235301}, NULL) = 0