Choosing the right backup strategy for Kafka-based environments

Kafka has become integral to many business-critical IT architectures due to its robust data replication and resilience against single node failures. However, ensuring business continuity and effective disaster recovery (DR) requires careful selection of a backup strategy. This blog examines the pros and cons of active-active and active-passive backup solutions in Kafka-based environments.
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Active-Active Backup

Active-active backup involves maintaining a primary Kafka cluster for all business operations alongside a secondary cluster that mirrors the primary in real time. In case of primary cluster failure, the secondary cluster takes over immediately, ensuring minimal downtime.

Advantages:

- Near-zero downtime during failover.
- Continuous availability for critical applications.

Disadvantages:‍

- Higher provisioning costs due to the need for duplicate infrastructure.
- Potential for replicating issues across both clusters.
- Increased maintenance and operational complexity.
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Active-Passive Backup

Active-passive backup involves storing the primary Kafka cluster’s data on an alternative storage medium, such as disks or blob storage. This approach is especially beneficial for preserving data over the long term and recovering from severe incidents that compromise data integrity.

Advantages:

- Comprehensive protection against data corruption and loss due to technical or human causes.
- Flexibility in implementing air-gapped or isolated storage solutions.

Disadvantages:

- Longer recovery times.
- Complexity in restoring data and ensure application continuity.
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Which strategy should you choose?

Businesses must evaluate several factors to determine the most suitable backup approach:

1. How important is business continuity? Assess acceptable downtime and the necessity of immediate switchover.
2. What is the impact of data loss? Consider the importance of data and the potential impact of data loss or corruption.
3. What is your risk profile? Understand the overall risk appetite and develop a robust DR strategy accordingly.
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Incremental Adoption

Backup strategies and required capabilities can evolve over time. For example, a business might start with a non-critical order processing segment focusing on stock reservations and forecasting. Initially, an active-passive backup approach may suffice, as minor downtime would not significantly impact operations. As more critical processes are integrated, active-active backup can be added to ensure continuous availability, while maintaining active-passive backup for comprehensive disaster recovery.
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Key Takeaways

- Understand the broader context and associated risks.
- Recognize that single solutions are often part of a larger strategy.
- Make informed decisions based on feasibility and practicality.
- Periodically reassess choices and strategies to ensure they remain aligned with business needs and technological advancements.