jstests/sharding/hash_shard_num_chunks.js


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// Hash sharding with initial chunk count set.

(function() {

var s = new ShardingTest({ shards: 3, mongos: 1 });
s.stopBalancer();

var dbname = "test";
var coll = "foo";
var db = s.getDB(dbname);

assert.commandWorked(db.adminCommand({ enablesharding: dbname }));
s.ensurePrimaryShard(dbname, 'shard0001');

assert.commandWorked(db.adminCommand({ shardcollection: dbname + "." + coll,
                                       key: { a: "hashed" },
                                       numInitialChunks: 500 }));

db.printShardingStatus();

var numChunks = s.config.chunks.count();
assert.eq(numChunks, 500 , "should be exactly 500 chunks");

var shards = s.config.shards.find();
shards.forEach(
    // check that each shard has one third the numInitialChunks
    function (shard){
        var numChunksOnShard = s.config.chunks.find({"shard": shard._id}).count();
        assert.gte(numChunksOnShard, Math.floor(500/3));
    }
);

// Check that the collection gets dropped correctly (which doesn't happen if pre-splitting fails to
// create the collection on all shards).
res = db.runCommand({ "drop": coll });
assert.eq(res.ok, 1, "couldn't drop empty, pre-split collection");

s.stop();

})();