CONTROL  [signalProcessingThread] got signal 1 (Hangup), will terminate after current cmd ends

2016-05-25T02:51:11.226+0000 I NETWORK  [initandlisten] connection accepted from 172.25.0.6:34372 #5004 (2 connections now open)
2016-05-25T02:51:11.488+0000 I CONTROL  [signalProcessingThread] got signal 1 (Hangup), will terminate after current cmd ends
2016-05-25T02:51:11.506+0000 I REPL     [signalProcessingThread] Stopping replication applier threads
2016-05-25T02:51:11.673+0000 I STORAGE  [WiredTigerRecordStoreThread for local.oplog.rs] shutting down
2016-05-25T02:51:12.329+0000 I CONTROL  [signalProcessingThread] now exiting
2016-05-25T02:51:12.329+0000 I NETWORK  [signalProcessingThread] shutdown: going to close listening sockets...
2016-05-25T02:51:12.329+0000 I NETWORK  [signalProcessingThread] closing listening socket: 6
2016-05-25T02:51:12.329+0000 I NETWORK  [signalProcessingThread] closing listening socket: 7
2016-05-25T02:51:12.329+0000 I NETWORK  [signalProcessingThread] closing listening socket: 8
2016-05-25T02:51:12.329+0000 I NETWORK  [signalProcessingThread] removing socket file: /tmp/mongodb-27017.sock
2016-05-25T02:51:12.330+0000 I NETWORK  [signalProcessingThread] shutdown: going to flush diaglog...
2016-05-25T02:51:12.330+0000 I NETWORK  [signalProcessingThread] shutdown: going to close sockets...
2016-05-25T02:51:12.337+0000 I STORAGE  [signalProcessingThread] WiredTigerKVEngine shutting down
2016-05-25T02:51:12.338+0000 I NETWORK  [conn5004] end connection 172.25.0.6:34372 (1 connection now open)
2016-05-25T02:51:12.338+0000 I NETWORK  [conn5003] end connection 172.25.0.7:58624 (0 connections now open)
2016-05-25T02:51:12.814+0000 I STORAGE  [signalProcessingThread] shutdown: removing fs lock...
2016-05-25T02:51:12.814+0000 I CONTROL  [signalProcessingThread] dbexit:  rc: 0

set1:PRIMARY> rs.conf();
{
        "_id" : "set1",
        "version" : 2,
        "members" : [
                {
                        "_id" : 0,
                        "host" : "xxxxxx:27017",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 3,
                        "tags" : {

                        },
                        "slaveDelay" : 0,
                        "votes" : 1
                },
                {
                        "_id" : 1,
                        "host" : "xxxxxx:27018",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 2,
                        "tags" : {

                        },
                        "slaveDelay" : 0,
                        "votes" : 1
                },
                {
                        "_id" : 2,
                        "host" : "xxxxxxxx:27019",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : 0,
                        "votes" : 1
                }
        ],
        "settings" : {
                "chainingAllowed" : true,
                "heartbeatTimeoutSecs" : 10,
                "getLastErrorModes" : {

                },
                "getLastErrorDefaults" : {
                        "w" : 1,
                        "wtimeout" : 0
                }
        }
}