Console shutdown event signaled

I installed ES on windows server, and run it as a windows service.
Yesterday, my ES cluster down due to master node down. I following log at the time master node down:

[2015-12-10 08:35:31] [info] [ 3428] Console SHUTDOWN event signaled
[2015-12-10 08:35:32] [info] [ 3428] Stopping service...
[2015-12-10 08:35:39] [info] [ 2572] Service SHUTDOWN signaled
[2015-12-10 08:35:40] [info] [ 556] Stopping service...
[2015-12-10 08:35:48] [info] [ 3428] Service stop thread completed.
[2015-12-10 08:35:49] [info] [ 556] Service stop thread completed.
[2015-12-10 08:35:49] [info] [ 2572] Run service finished.
[2015-12-10 08:35:49] [info] [ 2572] Commons Daemon procrun finished

Anyone experienced this issue? What could be root cause of service stopping?

anyone can share the idea for this issue?
Thanks in advance!