The document outlines 14 steps for setting up MongoDB sharding: 1) Create a sharded cluster with 3 shards 2) Add 100,000 documents to a collection in the cluster 3) Enable sharding on the database and collection and shard on the username field 4) Check that the collection is sharded and data is distributed across shards

1. Steps for Mongo Sharding
Step 1​ :mongo ­­nodb
Step 2​ : create a cluster with 3 shards
cluster = new ShardingTest({"shards" : 3, "chunksize" : 1})

2.
Step 3​ : list mongo DB processes
ps –a | grep mongo
Step 4​ : run this command from directory MongoDB bin directory to open another mongoDB
shell
./mongo ­­nodb

3. Step 5​: connect to the mongos (query router) process
db = (new Mongo("localhost:30999")).getDB("test")
Step 6​ :add some data into the sharing cluster
for (var i=0; i<100000; i++) {
db.users.insert({"username" : "user"+i, "created_at" : new Date()});
}

4. Step 7​: get a count of the number of users
db.users.count()
Step 8​: before setting up sharing ­ get sharing status
sh.status()

5. Step 9​: enable sharding in the test database
sh.enableSharding("test")
Step 10​:create a key for sharing on username
db.users.ensureIndex({"username" : 1})

6. Step 11:​ sh.shardCollection("test.users", {"username" : 1})
Step 12​: now get sharding status
sh.status()

7. Step 13​: run explain on find command
db.users.find({username: "user12345"}).explain()
Step 14:​ run explain on a find command that must get data from different shards
db.users.find( {$or: [{username: "user12345"}, {username: "user83108"}] }).explain()

8. Step 15:​ stop the cluster
cluster.stop()