Memory and storage engine basics (WiredTiger) in MongoDB - Mini Project: Build & Apply

Memory and Storage Engine Basics with WiredTiger in MongoDB

📖 Scenario: You are managing a MongoDB database for a small online bookstore. You want to understand how to set up and configure the WiredTiger storage engine, which is the default in MongoDB, to optimize memory usage and storage performance.

🎯 Goal: Build a simple MongoDB configuration and query setup that demonstrates how to check and configure WiredTiger memory and storage settings.

📋 What You'll Learn

Create a MongoDB collection named books with sample documents.

Define a variable to hold the WiredTiger cache size configuration.

Write a query to retrieve all documents from the books collection.

Add a command to display the current WiredTiger cache usage statistics.

💡 Why This Matters

🌍 Real World

Understanding and configuring WiredTiger memory and storage settings helps optimize MongoDB performance for real applications like online bookstores.

💼 Career

Database administrators and developers need to know how to monitor and tune storage engines like WiredTiger to ensure efficient data storage and retrieval.

1

Create the books collection with sample documents

Create a MongoDB collection called books and insert these exact documents: { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 }, { title: "1984", author: "George Orwell", year: 1949 }, and { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }.

MongoDB

// Insert the specified documents into the books collection
// Your code here

Need a hint?

Use db.books.insertMany() with an array of documents containing the exact fields and values.

2

Define WiredTiger cache size configuration variable

Create a variable called wiredTigerCacheSizeGB and set it to 1 to represent 1 gigabyte of WiredTiger cache size.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

// Define WiredTiger cache size variable
// Your code here

Need a hint?

Use const wiredTigerCacheSizeGB = 1 to set the cache size variable.

3

Query all documents from the books collection

Write a query using db.books.find() to retrieve all documents from the books collection.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

const wiredTigerCacheSizeGB = 1;

// Query all documents from books collection
// Your code here

Need a hint?

Use db.books.find() to get all documents.

4

Display WiredTiger cache usage statistics

Add the command db.serverStatus().wiredTiger.cache to display the current WiredTiger cache usage statistics.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

const wiredTigerCacheSizeGB = 1;

db.books.find()

// Show WiredTiger cache usage statistics
// Your code here

Need a hint?

Use db.serverStatus().wiredTiger.cache to check cache stats.