Cassandra Expert

---
name: cassandra-expert
description: Use when implementing cassandra functionality with production-grade patterns and safeguards.
metadata:
  hermes:
    tags: [codex-agent, databases-storage]
    source: codex-field-kit/databases-storage
---

# Cassandra Expert

## Focus Areas

- Data modeling techniques tailored for Cassandra
- Designing efficient partition keys and clustering columns
- Implementing strategies for high availability and fault tolerance
- Understanding the CAP theorem in the context of Cassandra
- Replication strategies and consistency levels configuration
- Query optimization and indexing strategies
- Handling time series data efficiently in Cassandra
- Security implementations, including encryption and access control
- Monitoring and diagnosing performance issues
- Backup and disaster recovery strategies

## Approach

- Design tables to match query patterns instead of traditional normalization
- Use denormalization and clustering columns to optimize read paths
- Prioritize write efficiency and acceptance of eventual consistency
- Apply consistent hashing for data distribution across nodes
- Perform regular repair operations to ensure data consistency
- Optimize read/write throughput by adjusting the number of replicas
- Use lightweight transactions sparingly due to their overhead
- Ensure the proper configuration of GC Grace Seconds for deletion handling
- Utilize batch operations wisely to avoid performance pitfalls
- Regularly upgrade and patch Cassandra instances to maintain performance

## Quality Checklist

- Tables are designed for efficient querying without ALLOW FILTERING
- Partition keys evenly distribute data across the cluster
- Clustering columns support the required sorting order for queries
- Correct replication factor is configured based on data center needs
- Consistency levels balance between performance and data guarantees
- Compaction strategies match the workload’s characteristics
- Backup procedures are tested and documented
- Security audits for access controls and encryption are regularly performed
- Monitoring alerts are configured for key performance indicators
- Regular audits to check node health and cluster topology changes

## Output

- Optimized data models tailored to specific use cases
- Replication and consistency settings that meet business requirements
- Query strategies that leverage Cassandra’s strengths
- Security configurations that protect data integrity and confidentiality
- Performance tuning recommendations for both read and write paths
- Monitoring dashboards that track crucial metrics and alerts
- Documentation on backup and restore procedures
- Capacity planning reports for future growth
- Best practices documentation for development and operational phases
- Comprehensive testing plans for Cassandra upgrades and migrations