By Jeff Carpenter

You might have heard of Apache Cassandra, the open-source NoSQL database. And you might know that some big, very successful companies rely on it, including LinkedIn, Netflix, The Home Depot, and Apple.

But did you know that Cassandra is used by a huge range of companies — including small, cloud-native application builders, financial firms, and broadcasters?

Here, I’ll give you an overview of Cassandra, along with a few reasons why this database might just be the right way to persist data at your organization and ensure your data and the apps that your developers build on it are infinitely scalable, secure, and fast.

A (very abridged) look at the database landscape

Many people in technology first became familiar with relational databases like Oracle DB or MySQL. They’re very powerful because they ensure data consistency and availability at the same time, and they’re effective and relatively easy to use — as long as your databases are running on the same machine.

Apache Cassandra 4.1 is generally available! Read more

But if you need to run more transactions or need more space to store your data, you’ll run into upper limits pretty quickly, as relational databases can’t scale efficiently.

The solution? Split the data among multiple machines and create a distributed system. NoSQL (“Not only SQL”) databases were invented to cope with these new requirements of volume (capacity), velocity (throughput), and variety (format) of big data.

It was born out of necessity, as the rise of Big Tech over the past decade has driven the global data sphere to skyrocket 15-fold; relational databases simply can’t cope with the new data volume or new performance requirements. Huge global operations like Google, Facebook, and LinkedIn created NoSQL databases to enable them to scale efficiently, go global, and achieve zero downtime.

Cassandra’s early days

In the mid-2000s, engineers at young, fast-growing Facebook had a problem: how could they store and access the mushrooming data created by Messenger, the platform that enabled users of the social networking site to communicate with one another? Nothing on the market could handle the hundreds of millions of users that were on the platform at peak times, spread across tens of thousands of servers spread across data centers around the world.

So, Facebook’s team built their own database to enable users to search their Messenger inboxes. It replicated data across geographies to keep latencies down, handled billions of writes per day, and could scale as the number of users grew. (You can geek out on the original Facebook Cassandra paper, authored by its creators, here).

As it became clear that this technology was suitable for other purposes, the company gave Cassandra to the Apache Software Foundation (ASF), where it became an open-source project (it was voted into a top-level project in 2010).

Cassandra’s scalability was impressive, but its reliability also sets it apart among databases. Because of its geographic distribution and the fact that data is replicated across multiple datacenters, Cassandra’s uptime and disaster recovery capabilities are unparalleled. This quickly caught the eye of other rising web stars, like Netflix. The company launched its streaming service in 2007 using an Oracle database housed in a single data center. The company’s rapid growth quickly highlighted the danger of managing data at a single point of failure. By 2013, most of Netflix’s data was housed in Cassandra. 

Cassandra has become the de facto standard database for high-growth applications that need reliability, high performance, and scalability: it’s used by approximately 90% of the Fortune 100, and a bunch of relatively recent developments are making it even more accessible to a wider range of organizations.

Why Cassandra?

Let’s quickly recap some of the unique capabilities of Cassandra:

Scalability – There are essentially no limitations on volume and velocity. Because it’s partitioned over a distributed architecture, Cassandra is capable of handling various data types at petabyte scale.Speed – Read-write performance is unmatched, thanks in part to Cassandra’s distributed nature — it can operate across multiple instances called “nodes.” A single node is very performant, but a cluster with multiple nodes and data centers brings throughput to the next level. Decentralization means that every node can deal with any request, read, or write.Availability – Theoretically, organizations can achieve 100% uptime thanks to data replication, decentralization, and a topology-aware placement strategy that replicates to multiple data centers, eliminating the waste associated with the traditional practice of maintaining duplicative infrastructure for disaster recovery.Geographically distributed – Multi-data center deployments provide exceptional disaster tolerance while keeping data close to clients around the globe, reducing latency (learn more about global data distribution here).Platform and vendor agnostic – Cassandra isn’t bound to any platform or service provider, which enables organizations to build hybrid- and multi-cloud solutions. It also doesn’t belong to any commercial vendor; the fact that it’s offered by the open-source, non-profit ASF means it’s openly available and continuously improving.

For more details, see this excellent Cassandra overview provided by the ASF.

Why Cassandra for your organization?

Online banking services, airline booking systems, and popular retail apps. These modern applications and workloads — many of which operate at huge, distributed scale — should never go down. Cassandra’s seamless and consistent ability to scale to hundreds of terabytes, along with its exceptional performance under heavy loads, has made it a key part of the data infrastructures of companies that operate these kinds of applications.

For instance, Best Buy, the world’s biggest multichannel consumer electronics retailer, describes Cassandra as “flawless” in how it handles huge spikes in holiday shopping traffic.

But Cassandra isn’t just for big, established sector leaders like Best Buy or Bloomberg. It’s a powerful data store for developers and architects who build high-growth applications at organizations of all sizes. Consider Praveen Viswanath, a cofounder of Alpha Ori Technologies, which offers an IOT platform for data acquisition from ships and processing and analytics for their operators.

Having experienced the power of the NoSQL database in earlier roles, Viswanath again turned to Cassandra — delivered via DataStax’s Astra DB cloud service — for its distributed reliability and high throughput, as Alpha Ori’s platform required the constant gathering of thousands of data points from the 40 or so major systems aboard the over 260 ships that it served.

Because of his team’s need to focus on development rather than database operation, Viswanath chose the Astra DB managed service, a serverless solution that scales up and down when needed.

A flourishing ecosystem

The availability of Cassandra as a managed service is one way that this powerful database is reaching more organizations. But there’s also an ecosystem of complementary open-source technologies that have sprung up around Cassandra to make it simpler for developers to build apps with it.

Stargate is an open-source data gateway that provides a pluggable API layer that greatly simplifies developer interaction with any Cassandra database. REST, GraphQL, Document, and gRPC APIs make it easy to just start coding with Cassandra without having to learn the complexities of CQL and Cassandra data modeling.

K8ssandra is another open-source project that demonstrates this approachability, making it possible to deploy Cassandra on any Kubernetes engine, from the public cloud providers to VMWare and OpenStack. K8ssandra extends the Kubernetes promise of application portability to the data tier, making it easier to avoid vendor-lock in.

A vibrant future

As a highly active open source project, Cassandra is always being updated and extended by a vibrant community of very smart people at companies like Apple, Netflix, and my employer, DataStax. Indeed, the Apache Software Foundation today announced the general availability of Cassandra 4.1. Through exciting innovations like ACID transaction support (long a holy grail of distributed NoSQL databases) and improved indexing, we are working to make Cassandra more powerful, easy to use, and ready for the future.

Want to learn more about Apache Cassandra? Register now for the Cassandra Summit, which takes place in San Jose, Calif., March 13-14, 2023.

About Jeff Carpenter:

DataStax

Jeff has worked as a software engineer and architect in multiple industries and as a developer advocate helping engineers succeed with Apache Cassandra. He’s involved in multiple open source projects in the Cassandra and Kubernetes ecosystems including Stargate and K8ssandra. Jeff is coauthor of the O’Reilly books Cassandra: The Definitive Guide and Managing Cloud Native Data on Kubernetes.

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