Book Image

MongoDB Administrator???s Guide

By : Cyrus Dasadia
Book Image

MongoDB Administrator???s Guide

By: Cyrus Dasadia

Overview of this book

MongoDB is a high-performance and feature-rich NoSQL database that forms the backbone of the systems that power many different organizations. Packed with many features that have become essential for many different types of software professional and incredibly easy to use, this cookbook contains more than 100 recipes to address the everyday challenges of working with MongoDB. Starting with database configuration, you will understand the indexing aspects of MongoDB. The book also includes practical recipes on how you can optimize your database query performance, perform diagnostics, and query debugging. You will also learn how to implement the core administration tasks required for high-availability and scalability, achieved through replica sets and sharding, respectively. You will also implement server security concepts such as authentication, user management, role-based access models, and TLS configuration. You will also learn how to back up and recover your database efficiently and monitor server performance. By the end of this book, you will have all the information you need—along with tips, tricks, and best practices—to implement a high-performance MongoDB solution.
Table of Contents (17 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Moving non-sharded collection data from one shard to another


In this recipe, we will look at how to migrate non-sharded data to another shard.

Getting ready

We need a sharded cluster, preferably the one we created in the previous recipe.

How to do it...

  1. Connect to the mongos service and inspect the shard status:
use myShardedDB

sh.status()

--- Sharding Status ---
 <-- output truncated -->
 databases:
 { "_id" : "myShardedDB", "primary" : "shard0002", "partitioned" : true }
 <-- output truncated -->
  1. Insert a document in the new (non-sharded) collection of the sharded database:
db.my_col.insert({foo: 'bar'})
  1. Confirm that the document was stored on the primary shard by fetching the document:
db.my_col.find({foo: 'bar'}).explain()['queryPlanner']['winningPlan']

{
 "stage" : "SINGLE_SHARD",
 "shards" : [
 {
 "shardName" : "shard0002",
 "<--output truncated-->
  1. Switch the primary to a different shard:
use admin

mongos> db.runCommand( { movePrimary: 'myShardedDB', to: 'shard0000' ...