Hi

There is a replica set with 3 member (primary, secondary, arbiter ). The secondary shut down unexpectedly but gracefully.

Server resources utilization is normal.

Attaching logs below:

2019-01-03T07:30:09.367+0000 I CONTROL [signalProcessingThread] got signal 15 (Terminated), will terminate after current cmd ends
2019-01-03T07:30:09.369+0000 I NETWORK [signalProcessingThread] shutdown: going to close listening sockets...
2019-01-03T07:30:09.369+0000 I NETWORK [signalProcessingThread] removing socket file: /tmp/mongodb-10001.sock
2019-01-03T07:30:09.370+0000 I REPL [signalProcessingThread] shutting down replication subsystems
2019-01-03T07:30:09.370+0000 I REPL [signalProcessingThread] Stopping replication reporter thread
2019-01-03T07:30:09.374+0000 I REPL [SyncSourceFeedback] SyncSourceFeedback error sending update to mongo7:10001: CallbackCanceled: Reporter no longer valid
2019-01-03T07:30:09.374+0000 I REPL [signalProcessingThread] Stopping replication fetcher thread
2019-01-03T07:30:09.374+0000 I REPL [signalProcessingThread] Stopping replication applier thread
2019-01-03T07:30:09.376+0000 I REPL [rsBackgroundSync] Replication producer stopped after oplog fetcher finished returning a batch from our sync source. Abandoning this batch of oplog entries and re-evaluating our sync source.
2019-01-03T07:30:09.376+0000 I REPL [rsBackgroundSync] Stopping replication producer
2019-01-03T07:30:09.376+0000 I REPL [rsSync-0] Finished oplog application
2019-01-03T07:30:09.376+0000 I REPL [signalProcessingThread] Stopping replication storage threads
2019-01-03T07:30:09.393+0000 I ASIO [signalProcessingThread] Dropping all pooled connections to mongo7:10001 due to ShutdownInProgress: Shutting down the connection pool
2019-01-03T07:30:09.395+0000 I ASIO [signalProcessingThread] Dropping all pooled connections to mongo7.arb:10001 due to ShutdownInProgress: Shutting down the connection pool
2019-01-03T07:30:09.395+0000 I ASIO [signalProcessingThread] Dropping all pooled connections to mongo7:10001 due to ShutdownInProgress: Shutting down the connection pool
2019-01-03T07:30:09.396+0000 I ASIO [signalProcessingThread] Dropping all pooled connections to mongo7:20001 due to ShutdownInProgress: Shutting down the connection pool
2019-01-03T07:30:09.396+0000 I ASIO [signalProcessingThread] Dropping all pooled connections to mongo4:20001 due to ShutdownInProgress: Shutting down the connection pool
2019-01-03T07:30:09.396+0000 I ASIO [signalProcessingThread] Dropping all pooled connections to mongo7:10001 due to ShutdownInProgress: Shutting down the connection pool
2019-01-03T07:30:09.396+0000 I ASIO [signalProcessingThread] Dropping all pooled connections to mongo1:20001 due to ShutdownInProgress: Shutting down the connection pool
2019-01-03T07:30:09.397+0000 W SHARDING [signalProcessingThread] error encountered while cleaning up distributed ping entry for mongo81:10001:1544870506:-5777183799470285182 :: caused by :: ShutdownInProgress: Shutdown in progress
2019-01-03T07:30:09.399+0000 W SHARDING [signalProcessingThread] cant reload ShardRegistry :: caused by :: CallbackCanceled: Callback canceled
2019-01-03T07:30:09.400+0000 I CONTROL [signalProcessingThread] Shutting down free monitoring
2019-01-03T07:30:09.401+0000 I FTDC [signalProcessingThread] Shutting down full-time diagnostic data capture
2019-01-03T07:30:09.408+0000 I STORAGE [WTOplogJournalThread] oplog journal thread loop shutting down
2019-01-03T07:30:09.409+0000 I STORAGE [signalProcessingThread] WiredTigerKVEngine shutting down
2019-01-03T07:30:10.065+0000 I STORAGE [signalProcessingThread] shutdown: removing fs lock...
2019-01-03T07:30:10.066+0000 I CONTROL [signalProcessingThread] now exiting
2019-01-03T07:30:10.066+0000 I CONTROL [signalProcessingThread] shutting down with code:0