Apache Cassandra explained in 5 minutes or less.
- What is Apache Cassandra?
- What is NoSQL?
- How does Apache Cassandra work?
- Cassandra architecture
- Apache Cassandra Features
- #1. open source
- #2. Uses column-wide architecture
- #3. Distributed
- #4. query design first
- Benefits of Apache Cassandra
- learning resources
- #1. Apache Cassandra: everything you need to know
- #2. Become a Certified Cassandra Developer: Practice Exams
- #3. Apache Cassandra Fundamentals
- #4. Mastering Apache Cassandra
- Last words
Apache Cassandra is an open source NoSQL distributed database.
What is Apache Cassandra?
Before going open source, Apache Cassandra was initially designed at Facebook (now Meta) to combine features from Amazon’s DynamoDB and Google’s Bigtable.
It is widely used by companies like Netflix, Uber, and Facebook due to its high availability and scalability.
This article will explain how Apache Cassandra is structured, how it works, and the different features and benefits of using it as part of your technology stack.
What is NoSQL?
Apache Cassandra belongs to the group of databases known as NoSQL databases. Unlike SQL or relational databases, NoSQL databases do not use SQL or relationships the way SQL databases do.
This creates advantages in terms of ease of use and flexibility, while sacrificing the ability to perform more advanced queries. However, both NoSQL and SQL databases have their places where they each shine.
How does Apache Cassandra work?
Cassandras runs using the Cassandra Query Language (CQL), which is syntactically very similar to the Structured Query Language (SQL) used by relational databases.
However, it does not support certain features, such as joins, that most relational databases have. This is because Cassandra is a query-first database. That means that the database is designed based on the queries that will be performed.
Tables are then created to provide enough data for each query without the need to join multiple tables. This makes it fast. It can be installed on all major operating systems.
At the most basic level, Cassandra is made up of nodes. Data is stored in nodes, and all records with the same key are stored in the same node. This makes querying faster than SQL databases, where multiple tables can be run on multiple machines.
Data is replicated between nodes for high availability using a replication factor specified by the database creator. A group of nodes that store all the data in a database is called a data center.
A group of data centers forms a cluster. Having multiple data centers means data is always available even when one data center goes offline unexpectedly.
Apache Cassandra Features
Among the most important and differentiating factors of Apache Cassandra and other market options are that it is:
#1. open source
Apache Cassandra is free and open source. This means that the source code is available online, making it less likely that you will have bugs and vulnerabilities that have yet to be discovered and patched.
This is important because user and business data are important assets that need to be protected.
#2. Uses column-wide architecture
Unlike most databases that store data in files based on the table it’s in, Apache Cassandra stores it by column.
This makes searching for a value in a column faster because you don’t have to search the entire row. As a result, Cassandra’s data searches are as fast as using indexes on other databases.
Apache Cassandra is distributed, which means it doesn’t run on a single machine. This helps ensure high data availability because it is replicated across different nodes and data centers. It also makes data access faster when data centers are geographically closer to the user.
#4. query design first
In traditional database design, tables are modeled around entities. Through normalization, the relationships between these entities are established and created in the databases.
Often when you query, the relationships span multiple tables. When these tables are stored on different machines, access to the data can be slow.
However, with Cassandra, you build tables based on the queries you intend to perform. All the data needed to satisfy that query is stored in a table.
Benefits of Apache Cassandra
- It’s free: The database management system itself is free and can be downloaded from the official Apache Cassandra website. However, the server infrastructure on which the database runs is not.
- Highly Available – Apache Cassandra is designed with resiliency in mind. It is designed with enough redundancy to remain functional when parts of the database go offline.
- It is scalable: additional nodes can be added to the database and storage capacity can be expanded with little or no downtime. This is ideal for creating high volume applications.
- It’s faster: Due to the wide-column architecture and query-first design, Apache Cassandra can perform faster compared to other database management systems.
Now, we’ll explore some of the best learning resources for understanding Apache Cassandra.
#1. Apache Cassandra: everything you need to know
This Udemy course on Apache Cassandra will take you from beginner to professional lessons covering topics from Cassandra Theoretical Overview to Cassandra Query Language.
The only requirement for this course is that you are familiar with databases in general and Linux systems.
#2. Become a Certified Cassandra Developer: Practice Exams
This certified course consists of two exams to help you prepare and practice for Datastax Academy’s Apache Cassandra Developer Certification exam.
Each exam is ninety minutes long and covers topics in Architecture, Modeling, and the Cassandra Query Language. The ideal audience for this course is developers who already know Cassandra but are looking to pursue professional certifications.
#3. Apache Cassandra Fundamentals
This developer book teaches you how to get started with Apache Cassandra. It teaches readers how to install Cassandra and set up a database cluster. Next, you’ll learn the Cassandra query language for interacting with your database.
You’ll also learn about tools you can use to monitor your cluster and debug queries. It’s ideal for someone who has never worked with Cassandra before and is looking to get started.
#4. Mastering Apache Cassandra
Written for people with some prior knowledge of Cassandra, this book teaches readers how to write more efficient Cassandra programs and configure Cassandra to be more efficient.
Additionally, it teaches how to integrate Apache Cassandra with Apache Spark to build data analytics systems.
Apache Cassandra is a powerful choice for a database in large-scale distributed systems. Its reliability, scalability, and speed make it a favorite choice among tech giants.
Learning and mastering this database will equip you with the skills to build software systems that reliably serve millions of users.
You can then refer to Apache Cassandra monitoring tools to monitor database performance.