You will need the following software to be able to smoothly sail through the chapters:

• MongoDB version 4+
• Apache Kafka version 1
• Apache Spark version 2+
• Apache Hadoop version 2+

You can download the example code files for this book from your account at www.packt.com. If you purchased this book elsewhere, you can visit www.packt.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packt.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Mastering-MongoDB-4.x-Second-Edition. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "In a sharded environment, each mongod applies its own locks, thus greatly improving concurrency."

A block of code is set as follows:

db.account.find( { "balance" : { $type : 16 } } );
db.account.find( { "balance" : { $type : "integer" } } );

Any command-line input or output is written as follows:

> db.types.insert({"a":4})
WriteResult({ "nInserted" : 1 })

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "The following screenshot shows the Zone configuration summary:"