Apache Cassandra in the Cloud : Amazon Keyspaces and Datastax Astra

Apache Cassandra is a distributed database that delivers the high availability, performance, and linear scalability today’s most demanding applications require. 

It offers operational simplicity and effortless replication across cloud service providers, data centers, and geographies, and it can handle petabytes of information 

and thousands of concurrent operations per second across hybrid cloud environments.

The arrival of managed cloud services to Cassandra is key to making this high-performance, highly-scaled distributed database accessible to a wider audience. 

Cassandra has long been known for its performance and scale, but never for its ease of use. Given those hurdles, 

But, as the popularity of AWS's DynamoDB service shows, there is strong demand for distributed databases.

The fact is, managed cloud services eliminate, patches, maintenance, and upgrades. 

The management API wraps an abstraction layer around the JMX (Java Management Extensions) 

that Cassandra uses to provide monitoring; JMX was used because Cassandra was written in Java. Without the API, JMX would be far more brittle, 

because it is a low-level construct that would otherwise have to be customized when running on different platforms. The new API is modular and operates, 

not only with K8s, but other operators such as Puppet.

Amazon Keyspaces (for Apache Cassandra) is a scalable, highly available, and managed Apache Cassandra–compatible database service. 

With Amazon Keyspaces, you can run your Cassandra workloads on AWS using the same Cassandra Query Language (CQL) API code, Cassandra drivers, and developer tools that you use today. 

You don’t have to provision, patch, or manage servers, and you don’t have to install, maintain, or operate software. Amazon Keyspaces is serverless, 

so you pay for only the resources you use and the service can automatically scale tables up and down in response to application traffic. 

You can build applications that serve thousands of requests per second with virtually unlimited throughput and storage. Amazon Keyspaces gives you the performance, 

elasticity, and enterprise features you need to operate business-critical Cassandra workloads at scale.

Tables are replicated three times in multiple AWS Availability Zones for high availability. Amazon Keyspaces offers a 99.99% availability SLA within an AWS Region. 

Tables are encrypted by default, and you can fine-tune access management, view log information in AWS CloudTrail, and you can provide security connectivity between 

your resources in Amazon Keyspaces and Amazon Virtual Private Cloud (Amazon VPC).

You can build applications on AWS by using open-source Cassandra APIs and drivers that are available for a wide range of programming languages such as Java, Python, Ruby, .NET, Node.js, PHP, C++, and Perl.

Pay for only what you use. There is no minimum fee.With Amazon Keyspaces, you do not need to provision storage in advance. Amazon Keyspaces monitors the billable size of your tables continuously to determine your storage charges.

Datastax Astra (for Apache Cassandra) Cloud-native Cassandra-as-a-Service built on Apache Cassandra.

it provides the ability to develop and deploy data-driven applications with a cloud-native service, without the hassles of database and infrastructure administration.

By automating tuning and configuration, DataStax Astra radically simplifies database operations.

Limits help enforce best practices by defining parameters for operations, such as table number and column size limits, ensuring the database operates with consistent performance and maintains cluster health.

Each Astra database employs a single capacity unit (CU) by default, which represents three database nodes that are grouped together. 

A single CU represents three replicas of approximately 500 GB of user data. CUs ensure high availability by implementing a consistent replication factor that is acceptable for development 

and production workloads.

To ensure that an Astra database doesn't exceed capacity, you can expand the database by adding CUs.

Developers can easily resize resources as their needs grow and change, and park databases when not in use to save costs and pay for only storage.