Title: Implement Distributed Circuit Breaker

[call-stack]

Distributed Circuit Breaker Implementation

Overview

This implementation introduces a distributed version of our circuit breaker pattern. The new DistributedCircuitBreaker extends the existing CircuitBreaker functionality by supporting any storage backend through a generic CacheClient interface, enabling distributed state management across multiple instances of an application.

Key Changes

• Added DistributedCircuitBreaker[T] struct that embeds the original CircuitBreaker[T]
• Implemented generic CacheClient interface that can be implemented by any storage solution (Redis, Memcached, etcd, etc.)
• Created StorageSettings to configure the distributed circuit breaker
• Implemented StoredState struct to represent the circuit breaker state in the storage backend
• Added helper methods for state retrieval and updates that work with any storage implementation

Features

Storage Flexibility

• Any storage system can be used by implementing the CacheClient interface
• Distributed state management across multiple application instances
• Fallback to in-memory state if the storage backend is unavailable
• Consistent circuit breaker behavior in distributed environments

Design Considerations

• Storage operations are abstracted through a simple interface requiring only GetState and SetState methods
• Generic type parameter T maintains type safety for the protected operation's result
• State synchronization handles race conditions through generation numbers
• Graceful degradation to local state when storage is unavailable

Next Steps

• Review the implementation for any potential race conditions or edge cases.
• Evaluate the need for additional configuration options
• Add more examples demonstrating integration with different storage solutions

This enhancement makes our circuit breaker implementation more flexible and adaptable to different distributed storage requirements while maintaining its core functionality and reliability.

[YoshiyukiMineo]

Thank you for your PR.

The latest implementation is under v2 directory. Could you move this change to v2?

[call-stack]

@YoshiyukiMineo I have move the implementation under v2. Could you please review it?

[call-stack]

Hi reviewers, I've addressed the previous feedback. Would appreciate another look when you have a chance. Thanks!

[YoshiyukiMineo]

Thanks. I have merged your PR into distributed branch temporarily. I will merge it into master after some slight change.