[Plugin] Create Circuit Breaker Plugin using Plugin Framework

[crivetimihai]

Overview

Create a Circuit Breaker Plugin that implements the circuit breaker pattern to prevent cascading failures and protect system stability.

Plugin Requirements

Plugin Details

• Name: CircuitBreakerPlugin
• Type: Self-contained (native) plugin
• File Location: plugins/circuit_breaker/
• Complexity: High

Functionality

• Implement circuit breaker pattern (closed, open, half-open states)
• Monitor failure rates and response times
• Automatic circuit opening on threshold breach
• Gradual recovery with half-open state
• Per-service circuit configuration

Hook Integration

• Primary Hooks: tool_pre_invoke, resource_pre_fetch
• Purpose: Prevent cascading failures
• Behavior: Block requests when circuit is open

Acceptance Criteria

• Plugin implements CircuitBreakerPlugin class
• Three-state circuit implementation
• Configurable failure thresholds
• Automatic recovery mechanism
• Per-service configuration
• Plugin manifest and documentation created
• Unit tests with >90% coverage

Priority

High - Reliability feature

Dependencies

• State management utilities
• Metrics collection libraries

Security Considerations

• Secure state management
• Protection against denial of service
• Audit logging for circuit state changes