Sharding in Action - MongoDB High Availability - page 115

Summary
In this chapter, you learned how to enable the sharding feature for a MongoDB database.
First of all, we prepared the environment and configured the hostnames for configuration
servers. Then, you learned how to start a configuration server and establish a configuration
server on a machine. You are recommended to host the configuration server on separate
machines in a production environment, but for development, you can host them on a single
machine.
After establishing the configuration servers, we added shards to sharding. For production
uses, it's better to use a replica set for each shard, but for development and testing environ-
ments, we can host standalone mongod instances. For our example, we added two shards,
one replica set, and a standalone mongod instance.
Also, you learned how to manage and control mongos instances using the mongo shell.
At the end, we created a database and collection to test the sharding feature on. You learned
that we should enable sharding for the database first, then using the mongo shell, we en-
abled sharding for each collection using shard keys. Using JavaScript codes and a for-loop,
we added some test data into the collection.
After adding data to the collection by using a query from the available shards, replica set,
and standalone MongoDB instance, we learned that MongoDB splits data between avail-
able chunks using a defined shard key.
In the next chapter, you will learn how to improve the response time of the server using the
methods that we learned in the previous chapters.