Open source Apache Cassandra® continues to stand out as an enterprise-proven solution for organizations seeking high availability, scalability and performance in a NoSQL database. (And hey, the brand-new 5.0 version is only making those statements even more true!) There’s a reason this database is trusted by some of the world’s largest and most successful companies.
That said, effectively harnessing the full spectrum of Cassandra’s powerful advantages can mean overcoming a fair share of operational complexity. Some folks will find a significant learning curve, and knowing what to expect is critical to success. In my years of experience working with Cassandra, it’s when organizations fail to anticipate and respect these challenges that they set the stage for their Cassandra projects to fall short of expectations.
Let’s look at the key areas where strong project management and following proven best practices will enable teams to evade common pitfalls and ensure a Cassandra implementation is built strong from Day 1.
Accurate Data Modeling Is a Must
Cassandra projects require a thorough understanding of its unique data model principles. Teams that approach Cassandra like a relationship database are unlikely to model data properly. This can lead to poor performance, excessive use of secondary indexes and significant data consistency issues.
On the other hand, teams that develop familiarity with Cassandra’s specific NoSQL data model will understand the importance of including partition keys, clustering keys and denormalization. These teams will know to closely analyze query and data access patterns associated with their applications and know how to use that understanding to build a Cassandra data model that matches their application’s needs step for step.
Configure Cassandra Clusters the Right Way
Accurate, expertly managed cluster configurations are pivotal to the success of Cassandra implementations. Get those cluster settings wrong and Cassandra can suffer from data inconsistencies and performance issues due to inappropriate node capacities, poor partitioning or replication strategies that aren’t up to the task.
Teams should understand the needs of their particular use case and how each cluster configuration setting affects Cassandra’s abilities to serve that use case. Attuning configurations to best support your application — including the right settings for node capacity, data distribution, replication factor and consistency levels — will ensure that you can harness the full power of Cassandra when it counts.
Take Advantage of Tunable Consistency
Cassandra gives teams the option to leverage the best balance of data consistency and availability for their use case. While these tunable consistency levels are a valuable tool in the right hands, teams that don’t understand the nuances of these controls can saddle their applications with painful latency and troublesome data inconsistencies.
Teams that learn to operate Cassandra’s tunable consistency levels properly and carefully assess their application’s needs — especially with read and write patterns, data sensitivity and the ability to tolerate eventual consistency — will unlock far more beneficial Cassandra experiences.
Perform Regular Maintenance
Regular Cassandra maintenance is required to stave off issues such as data inconsistencies and performance drop-offs. Within their Cassandra operational procedures, teams should routinely perform compaction, repair and node-tool operations to prevent challenges down the road, while ensuring cluster health and performance are optimized.
Anticipate Capacity and Scaling Needs
By its nature, success will yield new needs. Be prepared for your Cassandra cluster to grow and scale well into the future — that is what this database is built to do. Starving your Cassandra cluster for CPU, RAM and storage resources because you don’t have a plan to seamlessly add capacity is a way of plucking failure from the jaws of success. Poor performance, data loss and expensive downtime are the rewards for growing without looking ahead.
Plan for growth and scalability from the beginning of your Cassandra implementation. Practice careful capacity planning. Look at your data volumes, write/read patterns and performance requirements today and tomorrow. Teams with clusters built for growth will be ready to do so far more easily and affordably.
Make Changes With a Careful Testing/Staging/Prod Process
Teams that think they’re streamlining their process efficiency by putting Cassandra changes straight into production actually enable a pipeline for bugs, performance roadblocks and data inconsistencies. Testing and staging environments are essential for validating changes before putting them into production environments and will save teams countless hours of headaches.
At the end of the day, running all data migrations, changes to schema and application updates through testing and staging environments is far more efficient than putting them straight into production and then cleaning up myriad live issues.
Set Up Monitoring and Alerts
Teams implementing monitoring and alerts to track metrics and flag anomalies can mitigate trouble spots before they become full-blown service interruptions. The speed at which teams become aware of issues can mean the difference between a behind-the-scenes blip and a downtime event.
Have Backup and Disaster Recovery at the Ready
In addition to standing up robust monitoring and alerting, teams should regularly test and run practice drills on their procedures for recovering from disasters and using data backups. Don’t neglect this step; these measures are absolutely essential for ensuring the safety and resilience of systems and data.
The less prepared an organization is to recover from issues, the longer and more costly and impactful downtime will be. Incremental or snapshot backup strategies, replication that’s based in the cloud or across multiple data centers and fine-tuned recovery processes should be in place to minimize downtime, stress and confusion whenever the worst occurs.
Nurture Cassandra Expertise
The expertise required to optimize Cassandra configurations, operations and performance will only come with a dedicated focus. Enlisting experienced talent, instilling continuous training regimens that keep up with Cassandra updates, turning to external support and ensuring available resources — or all of the above — will position organizations to succeed in following the best practices highlighted here and achieving all of the benefits that Cassandra can deliver.
