var LOG_FUNCTION = "function log(msg) {var date = new Date(); jsTest.log('MONGOISSUE - ' + date.getHours() + ':' + date.getMinutes() + ':' + date.getSeconds() + ':' + date.getMilliseconds() + ' - ' + msg);}";
eval(LOG_FUNCTION);

var numDocs = 20000;

// Set up cluster.
log('SETTING UP CLUSTER...');
var st = new ShardingTest({shards: 2, other: {shardOptions: {storageEngine: 'mmapv1', verbose: 0}}});
var s = st.s0;
var d1 = st.shard1;
var coll = s.getDB("test").foo;
assert.commandWorked(s.adminCommand({enableSharding: coll.getDB().getName()}));
assert.commandWorked(s.adminCommand({shardCollection: coll.getFullName(), key: {_id: "hashed"}}));
log('INSERT START');
for (i=0; i<numDocs; i++) {
    coll.insert({_id: i});
}
log('INSERT END');
assert.commandWorked(coll.ensureIndex({a: 1}));

// Check document count.
var count = coll.find().itcount();
log("DOC COUNT: " + count);
assert.eq(numDocs, count);

// Configure server to increase reproducibility.
assert.commandWorked(d1.adminCommand({setParameter: 1, internalQueryExecYieldIterations: 2}));

function logChunk(chunk) { log('chunk ' + chunk['_id'] + ' shard ' + chunk['shard']); }
st.config.chunks.find().forEach(logChunk);

// Initiate migration and add data in parallel.
shell = startParallelShell(LOG_FUNCTION + " log('INSERT START'); var coll = db.getSiblingDB('test').foo; for (i=" + numDocs + "; i<" + (numDocs * 2) + "; i++) { coll.insert({_id: i}); }; log('INSERT END');", s.port);
sleep(500);
log('MOVECHUNK START');
var res = s.adminCommand({moveChunk: coll.getFullName(), find: {_id: 0}, to: "shard0000", _waitForDelete: true});
log('MOVECHUNK END');
assert.commandWorked(res);
st.config.chunks.find().forEach(logChunk);
shell();

// Re-check document count.
var count = coll.find().itcount();
log("DOC COUNT: " + count);
assert.eq(numDocs * 2, count);