Book Image

Mastering MongoDB 6.x - Third Edition

By : Alex Giamas
Book Image

Mastering MongoDB 6.x - Third Edition

By: Alex Giamas

Overview of this book

MongoDB is a leading non-relational database. This book covers all the major features of MongoDB including the latest version 6. MongoDB 6.x adds many new features and expands on existing ones such as aggregation, indexing, replication, sharding and MongoDB Atlas tools. Some of the MongoDB Atlas tools that you will master include Atlas dedicated clusters and Serverless, Atlas Search, Charts, Realm Application Services/Sync, Compass, Cloud Manager and Data Lake. By getting hands-on working with code using realistic use cases, you will master the art of modeling, shaping and querying your data and become the MongoDB oracle for the business. You will focus on broadly used and niche areas such as optimizing queries, configuring large-scale clusters, configuring your cluster for high performance and availability and many more. Later, you will become proficient in auditing, monitoring, and securing your clusters using a structured and organized approach. By the end of this book, you will have grasped all the practical understanding needed to design, develop, administer and scale MongoDB-based database applications both on premises and on the cloud.
Table of Contents (22 chapters)
1
Part 1 – Basic MongoDB – Design Goals and Architecture
4
Part 2 – Querying Effectively
11
Part 3 – Administration and Data Management
16
Part 4 – Scaling and High Availability

Sharding recovery

In this section, we will explore different failure types and how we can recover in a sharded environment. Failure in a distributed system can take multiple forms and shapes. In this section, we will cover all possible failure cases, as outlined here:

  • A mongos process breaks
  • A mongod process breaks
  • A config server breaks
  • A shard goes down
  • The entire cluster goes down

In the following sections, we will describe how each component failure affects our cluster and how to recover.

mongos

The mongos process is a relatively lightweight process that holds no state. In the case that the process fails, we can just restart it or spin up a new process on a different server. It’s recommended that mongos processes are located in the same server as our application, and so it makes sense to connect from our application using the set of mongos servers that we have colocated in our application servers to ensure high availability (HA) of mongos...