Query Result Mismatch in MongoDB (Sharded Environment)

Question

What I am doing is:

1) Created a new shard database. 2) Created two new shard collections (source and target) and dumped data in it 3) Then I am running two map reduce on two sharded collections one after the other And putting the result of both the MR in same collection (say j_30052014125600).

This is perfectly working fine. I am running all this on sharded cluster having

• 1 shard server
• 1 config server
• 2 replicas

The problem is when I executed the query to count the documents

db.j_30052014125600.find({"value.ID": 305763}).count(),

I got the count 2 which is correct, but when I executed the find query

db.j_30052014125600.find({"value.ID": 305763}),

I got just one document.

I have copied here a small screenshot which will help you guys to understand.

Why this is so? Can any one please explain me?

Thanks

Update:

mongos> db.j_30052014125600.find({"value.ID": 305763}).explain()
{
    "clusteredType" : "ParallelSort",
    "shards" : {
        "firstset/192.168.1.1:10002,192.168.1.2:10001" : [
            {
                "cursor" : "BasicCursor",
                "isMultiKey" : false,
                "n" : 0,
                "nscannedObjects" : 519034,
                "nscanned" : 519034,
                "nscannedObjectsAllPlans" : 519034,
                "nscannedAllPlans" : 519034,
                "scanAndOrder" : false,
                "indexOnly" : false,
                "nYields" : 0,
                "nChunkSkips" : 1,
                "millis" : 508,
                "indexBounds" : {

                },
                "server" : "VM1:10002"
            }
        ],
        "secondset/192.168.1.1:10003,192.168.1.3:10004" : [
            {
                "cursor" : "BasicCursor",
                "isMultiKey" : false,
                "n" : 1,
                "nscannedObjects" : 280944,
                "nscanned" : 280944,
                "nscannedObjectsAllPlans" : 280944,
                "nscannedAllPlans" : 280944,
                "scanAndOrder" : false,
                "indexOnly" : false,
                "nYields" : 0,
                "nChunkSkips" : 0,
                "millis" : 289,
                "indexBounds" : {

                },
                "server" : "VM2:10004"
            }
        ]
    },
    "cursor" : "BasicCursor",
    "n" : 1,
    "nChunkSkips" : 1,
    "nYields" : 0,
    "nscanned" : 799978,
    "nscannedAllPlans" : 799978,
    "nscannedObjects" : 799978,
    "nscannedObjectsAllPlans" : 799978,
    "millisShardTotal" : 797,
    "millisShardAvg" : 398,
    "numQueries" : 2,
    "numShards" : 2,
    "millis" : 533
}