Book Image

Learn MongoDB 4.x

By : Doug Bierer
Book Image

Learn MongoDB 4.x

By: Doug Bierer

Overview of this book

When it comes to managing a high volume of unstructured and non-relational datasets, MongoDB is the defacto database management system (DBMS) for DBAs and data architects. This updated book includes the latest release and covers every feature in MongoDB 4.x, while helping you get hands-on with building a MongoDB database app. You’ll get to grips with MongoDB 4.x concepts such as indexes, database design, data modeling, authentication, and aggregation. As you progress, you’ll cover tasks such as performing routine operations when developing a dynamic database-driven website. Using examples, you’ll learn how to work with queries and regular database operations. The book will not only guide you through design and implementation, but also help you monitor operations to achieve optimal performance and secure your MongoDB database systems. You’ll also be introduced to advanced techniques such as aggregation, map-reduce, complex queries, and generating ad hoc financial reports on the fly. Later, the book shows you how to work with multiple collections as well as embedded arrays and documents, before finally exploring key topics such as replication, sharding, and security using practical examples. By the end of this book, you’ll be well-versed with MongoDB 4.x and be able to perform development and administrative tasks associated with this NoSQL database.
Table of Contents (22 chapters)
Section 1: Essentials
Section 2: Building a Database-Driven Web Application
Section 3: Digging Deeper
Section 4: Replication, Sharding, and Security in a Financial Environment
Working with Complex Documents Across Collections

What is a sharded cluster?

In order to properly understand a MongoDB sharded cluster, you need to know something about its key components: shards, mongos, and the config server. Here is a brief summary of the key components:

  • Shards: A shard is literally a fragment of a database collection. Shards are used when the amount of data in a single collection is extremely large. Accordingly, the best practice is for each shard to reside on a replica set (see Chapter 13, Deploying a Replica Set). A sharded cluster is a term used to represent the group of servers or replica sets that, as a whole, represent the fragmented collection.
  • mongos: A mongos instance routes database queries to the appropriate shard. It is started much like a mongod (the MongoDB server daemon) instance, with many of the same startup options. Also, much like mongod, you can open a shell on a mongos instance in order to monitor and manage a sharded cluster. Program application queries must be directed to a mongos instance...