I have run db.currentOp(true) on MongoShell (2.6.9) this gives more information about multiple client a, multiple connectionId and operation id

Output of db.currentOp(true) on MongoShell (2.6.9)

{
"inprog" : [
{
"opid" : 0,
"active" : false,
"op" : "none",
"ns" : "",
"query" : {

},
"desc" : "signalProcessingThread",
"threadId" : "0x7f41b3245700",
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" : {

},
"timeAcquiringMicros" : {

}
}
},
{
"opid" : 1,
"active" : false,
"op" : "none",
"ns" : "",
"query" : {

},
"desc" : "DataFileSync",
"threadId" : "0x7f41b2a44700",
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" : {

},
"timeAcquiringMicros" : {

}
}
},
{
"opid" : 10,
"active" : false,
"op" : "insert",
"ns" : "local.startup_log",
"insert" : {

},
"client" : "0.0.0.0:0",
"desc" : "initandlisten",
"threadId" : "0x7f41b4b37b80",
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" :

{ "R" : NumberLong(0), "W" : NumberLong(526) }

,
"timeAcquiringMicros" :

{ "r" : NumberLong(0), "w" : NumberLong(1) }

}
},
{
"opid" : 3,
"active" : false,
"op" : "none",
"ns" : "",
"query" : {

},
"desc" : "journal",
"threadId" : "0x7f41b1a42700",
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" :

{ "R" : NumberLong(204900), "W" : NumberLong(75759) }

,
"timeAcquiringMicros" :

{ "R" : NumberLong(109752), "W" : NumberLong(26000) }

}
},
{
"opid" : 5,
"active" : false,
"op" : "none",
"ns" : "",
"query" : {

},
"desc" : "clientcursormon",
"threadId" : "0x7f41b1241700",
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" :

{ "r" : NumberLong(31875), "w" : NumberLong(0) }

,
"timeAcquiringMicros" :

{ "r" : NumberLong(14823), "w" : NumberLong(0) }

}
},
{
"opid" : 3790,
"active" : false,
"op" : "query",
"ns" : "local.system.indexes",
"query" : {
"expireAfterSeconds" :

{ "$exists" : true }

},
"client" : "0.0.0.0:0",
"desc" : "TTLMonitor",
"threadId" : "0x7f41b023f700",
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" :

{ "r" : NumberLong(33), "w" : NumberLong(0) }

,
"timeAcquiringMicros" :

{ "r" : NumberLong(1), "w" : NumberLong(0) }

}
},
{
"opid" : 105,
"active" : false,
"op" : "query",
"ns" : "",
"query" :

{ "isMaster" : 1, "forShell" : 1 }

,
"client" : "127.0.0.1:48910",
"desc" : "conn1",
"threadId" : "0x7f41b4b34700",
"connectionId" : 1,
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" : {

},
"timeAcquiringMicros" : {

}
}
},
{
"opid" : 8,
"active" : false,
"op" : "none",
"ns" : "",
"query" : {

},
"desc" : "RangeDeleter",
"threadId" : "0x7f41afa3e700",
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" : {

},
"timeAcquiringMicros" : {

}
}
},
{
"opid" : 1399,
"active" : false,
"op" : "query",
"ns" : "admin",
"query" :

{ "listDatabases" : 1 }

,
"client" : "127.0.0.1:48924",
"desc" : "conn10",
"threadId" : "0x7f41a8a3c700",
"connectionId" : 10,
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" :

{ "R" : NumberLong(5), "W" : NumberLong(0), "r" : NumberLong(24), "w" : NumberLong(0) }

,
"timeAcquiringMicros" :

{ "R" : NumberLong(1), "W" : NumberLong(0), "r" : NumberLong(7), "w" : NumberLong(0) }

}
},
{
"opid" : 3796,
"active" : false,
"op" : "query",
"ns" : "",
"query" :

{ "ismaster" : 1 }

,
"client" : "127.0.0.1:48923",
"desc" : "conn9",
"threadId" : "0x7f41a893b700",
"connectionId" : 9,
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" : {

},
"timeAcquiringMicros" : {

}
}
},
{
"opid" : 3175,
"active" : false,
"op" : "query",
"ns" : "",
"query" :

{ "isMaster" : 1 }

,
"client" : "127.0.0.1:48926",
"desc" : "conn12",
"threadId" : "0x7f41a8739700",
"connectionId" : 12,
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" : {

},
"timeAcquiringMicros" : {

}
}
},
{
"opid" : 3795,
"active" : false,
"op" : "query",
"ns" : "",
"query" :

{ "ismaster" : 1 }

,
"client" : "127.0.0.1:48925",
"desc" : "conn11",
"threadId" : "0x7f41a8638700",
"connectionId" : 11,
"waitingForLock" : false,
"numYields" : 0,
"lockStats" : {
"timeLockedMicros" : {

},
"timeAcquiringMicros" : {

}
}
}
]
}

when we run same command in Mongo Shell(3.0.5) this gives only single client , single Operation Id and multiple connection Id.

Output of db.currentOp(true) on MongoShell(3.x)

{
"inprog" : [

{ "desc" : "conn8", "threadId" : "0x2defd40", "connectionId" : 8, "active" : false }

,

{ "desc" : "conn6", "threadId" : "0x2defa00", "connectionId" : 6, "active" : false }

,

{ "desc" : "conn5", "threadId" : "0x2def860", "connectionId" : 5, "active" : false }

,

{ "desc" : "conn4", "threadId" : "0x2def6c0", "connectionId" : 4, "active" : false }

,

{ "desc" : "conn3", "threadId" : "0x2def520", "connectionId" : 3, "active" : false }

,

{ "desc" : "signalProcessingThread", "threadId" : "0x2dee000", "active" : false }

,

{ "desc" : "DataFileSync", "threadId" : "0x2dee4e0", "active" : false }

,

{ "desc" : "durability", "threadId" : "0x2dee680", "active" : false }

,

{ "desc" : "conn7", "threadId" : "0x2defba0", "connectionId" : 7, "active" : false }

,

{ "desc" : "journal writer", "threadId" : "0x2dee9c0", "active" : false }

,
{
"desc" : "clientcursormon",
"threadId" : "0x2deeea0",
"opid" : 8,
"active" : false,
"op" : "none",
"ns" : "local.Orders",
"query" : {

},
"numYields" : 0,
"locks" : {

},
"waitingForLock" : false,
"lockStats" : {
"Global" : {
"acquireCount" :

{ "r" : NumberLong(40) }

},
"MMAPV1Journal" : {
"acquireCount" :

{ "r" : NumberLong(20) }

},
"Database" : {
"acquireCount" :

{ "r" : NumberLong(20) }

},
"Collection" : {
"acquireCount" :

{ "R" : NumberLong(20) }

}
}
},
{
"desc" : "RangeDeleter",
"threadId" : "0x2deeb60",
"opid" : 6,
"active" : false,
"op" : "none",
"ns" : "",
"query" : {

},
"numYields" : 0,
"locks" : {

},
"waitingForLock" : false,
"lockStats" : {

}
},

{ "desc" : "initandlisten", "threadId" : "0x2dee1a0", "active" : false }

,

{ "desc" : "TTLMonitor", "threadId" : "0x2deed00", "active" : false }

,
{
"desc" : "conn1",
"threadId" : "0x2def1e0",
"connectionId" : 1,
"opid" : 83,
"active" : false,
"op" : "query",
"ns" : "",
"query" :

{ "isMaster" : 1, "forShell" : 1 }

,
"client" : "127.0.0.1:40793",
"numYields" : 0,
"locks" : {

},
"waitingForLock" : false,
"lockStats" : {

}
},

{ "desc" : "conn2", "threadId" : "0x2def380", "connectionId" : 2, "active" : false }

]
}