(function() {
    'use strict';

    var s = new ShardingTest({shards: 2, mongos: 1, other: {chunkSize: 1, enableBalancer: true}});

    assert.commandWorked(s.s0.adminCommand({enablesharding: "test"}));
    s.ensurePrimaryShard('test', 'shard0001');

    var S = "";
    while (S.length < 500) {
        S += "123123312312";
    }

    var N = 100000;

    var db = s.getDB("test");
    var bulk = db.foo.initializeUnorderedBulkOp();
    var bulk2 = db.bar.initializeUnorderedBulkOp();
    for (i = 0; i < N; i++) {
        bulk.insert({_id: i, s: S});
        bulk2.insert({_id: i, s: S, s2: S});
    }
    assert.writeOK(bulk.execute());
    assert.writeOK(bulk2.execute());

    s.printShardingStatus();

    function mytest(coll, i, loopNumber) {
        try {
            var x = coll.find({_id: i}).explain();
        } catch (e) {
            // Ignore stale shard version exceptions, since there are many migrations happening, and
            // mongos may not be able to complete the find within the stale version retries limit.
            if (e.message.contains("stale config")) {
                return;
            }
            throw e;
        }
        if (x)
            return;
        throw Error("can't find " + i + " in " + coll.getName() + " on loopNumber: " + loopNumber +
                    " explain: " + tojson(x));
    }

    for (var loopNumber = 0;; loopNumber++) {
        for (var i = 0; i < N; i++) {
            mytest(db.foo, i, loopNumber);
            mytest(db.bar, i, loopNumber);
            if (i % 1000 == 0)
                print(i);
        }

        s.printShardingStatus();

        if (loopNumber == 0) {
            assert.commandWorked(s.s0.adminCommand({shardcollection: "test.foo", key: {_id: 1}}));
            assert.commandWorked(s.s0.adminCommand({shardcollection: "test.bar", key: {_id: 1}}));
        }

        assert(loopNumber < 1000, "taking too long");

        if (s.chunkDiff("foo") < 12 && s.chunkDiff("bar") < 12) {
            break;
        }
    }

    s.stop();
})();