Brummer MCP Server

# Updated Plan Based on Assumption Testing **Updated**: January 31, 2025 **Original Plan**: Channel-based lock-free architecture **Validated Approach**: Atomic operations with immutable state ## Executive Summary Assumption testing revealed that channels are 15-67x SLOWER than mutexes, invalidating our primary assumption. However, testing atomic operations showed 30-300x FASTER performance than mutexes. This validates pivoting to an atomic-based approach. ## Plan Changes Required ### Architecture Pivot **Original**: Channel-based message passing for all state management **Updated**: Atomic pointer swapping with immutable state objects **Reason**: Channels proved 15-67x slower; atomics proved 30-300x faster ### Task Modifications #### Task: Implement State Management - **Original Scope**: Build channel-based state manager with goroutine orchestration - **Updated Scope**: Implement atomic pointer swapping with ProcessState struct - **Complexity Change**: Simpler (no goroutine coordination needed) - **Time Estimate**: Reduced from 2 weeks to 1 week #### Task: Process Registry - **Original Scope**: Channel-based registry with message passing - **Updated Scope**: sync.Map implementation for lock-free registry - **Complexity Change**: Much simpler (standard library component) - **Time Estimate**: Reduced from 1 week to 3 days ### New Tasks Required #### Task: Implement Immutable ProcessState - **Purpose**: Create immutable state objects for atomic swapping - **Dependencies**: None (can start immediately) - **Complexity**: Low (simple struct with convenience methods) - **Time Estimate**: 2 days #### Task: CAS Loop Implementation - **Purpose**: Implement compare-and-swap loops for state updates - **Dependencies**: ProcessState struct - **Complexity**: Medium (need to handle retry logic) - **Time Estimate**: 3 days ### Removed Tasks #### Task: Channel Orchestration Layer - **Reason**: Channels proved inefficient for this use case - **Replaced By**: Direct atomic operations #### Task: Message Protocol Design - **Reason**: No longer using message passing - **Replaced By**: Immutable state pattern ## Updated Timeline ### Phase 3A: Atomic State Implementation (Week 1) 1. Day 1-2: Create ProcessState struct and methods 2. Day 3-4: Implement atomic pointer operations 3. Day 5: Update hot-path code to use atomics ### Phase 3B: Registry Migration (Week 2) 1. Day 1-2: Replace map with sync.Map 2. Day 3: Update Manager methods 3. Day 4-5: Performance testing and optimization ### Phase 3C: Integration (Week 3) 1. Day 1-2: End-to-end testing 2. Day 3-4: Documentation and migration guide 3. Day 5: Production rollout preparation **Total Timeline**: 3 weeks (unchanged, but different work) ## Validated Technical Approach ### Core Pattern ```go // Immutable state type ProcessState struct { ID string Status ProcessStatus StartTime time.Time EndTime *time.Time ExitCode *int } // Atomic pointer type Process struct { state unsafe.Pointer // *ProcessState } // Lock-free read func (p *Process) GetState() *ProcessState { return (*ProcessState)(atomic.LoadPointer(&p.state)) } ``` ### Performance Characteristics - Read operations: 0.5ns (vs 16ns mutex, 1600ns channel) - Zero allocations for reads - Perfect scaling under concurrent load - Hardware-optimized execution ## Risk Mitigation Updates ### New Approach Benefits - Simpler implementation (no goroutine coordination) - Better performance (30-300x improvement) - Easier debugging (no channel deadlocks) - Proven pattern (used in high-performance systems) ### Implementation Risks - ABA problem: Mitigate with unique pointers - Memory ordering: Use atomic package correctly - Platform differences: Test on multiple architectures ## Success Metrics ### Performance Targets (Validated by Testing) - Single read: <1ns (achieved: 0.54ns) - Concurrent reads: <1ns (achieved: 0.24ns) - Memory allocation: 0 for reads (achieved) - Write performance: <100ns (achieved: 51ns) ### Architecture Goals - ✅ Lock-free reads - ✅ API compatibility - ✅ Incremental migration - ✅ Performance improvement ## Next Steps 1. Begin Phase 3A implementation with atomic ProcessState 2. Use validated patterns from prototype testing 3. Apply performance benchmarks as acceptance criteria 4. Document atomic patterns for team education