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

Starting mongod instances

At this point, you can start the mongod instance on each server according to the recommended procedure for the host OS. Thus, on a Windows server, for example, the mongod instance would be started as a service using the Windows Task Manager or an equivalent GUI option. In a Linux environment, you could simply type the following:

 mongod -f /etc/mongod.conf

As mentioned earlier, when starting the mongod instance manually (or using a shell script), you can specify replication options as command-line switches. The preferred approach, however, is to place replication settings into the mongod.conf (or equivalent) file on each member of the replica set. 

For the purposes of this chapter, as mentioned previously, we will start the three Docker containers using the following command:

docker-compose up

The result is shown here:

We are now ready to initiate the replica set.