Context and Problem
In event-driven and messaging systems, sometimes messages or events fail to process correctly or could be malicious.
- Processing failures due to malformed or invalid data.
- Potential security threats from compromised or suspicious messages.
- Difficulty in identifying and resolving issues in production environments.
- Increased risk of system instability due to unhandled errors.
Solution
The Quarantine pattern isolates problematic messages or events to ensure they do not affect the main system while they are investigated or corrected.
- Detect failed or suspicious messages during processing.
- Move these messages into a quarantine area for further analysis.
- Provide access to logs and metadata to investigate the issue.
- Implement retry or escalation mechanisms if necessary.
- Review quarantined messages regularly and take corrective actions.
Benefits
- Fault isolation
- Keeps faulty messages from affecting the rest of the system.
- Enhanced security
- Protects the system from potentially harmful messages.
- Simplified debugging
- Provides a centralized area for analyzing failed events.
- Improved system stability
- Reduces the likelihood of cascading failures in the system.
Trade-offs
- Storage overhead
- Requires space to store quarantined messages until resolution.
- Delayed resolution
- Quarantined messages need to be manually reviewed and fixed.
- Complexity
- Requires additional logic for managing the quarantine process.
Issues and Considerations
- Message resolution
- How and when to resolve quarantined messages (e.g., retry, discard, or escalate).
- Security concerns
- Ensuring that malicious messages are properly handled to avoid system compromise.
- Monitoring
- Effective monitoring and alerting mechanisms for quarantined messages.
When to Use This Pattern
- When dealing with unreliable or potentially malicious messages.
- When processing errors need isolation from the main system.
- When system stability is critical, and failed messages should not impact functionality.
- When diagnosing and resolving issues in a controlled manner is needed.