/distributed-systems

name: distributed-systems
license: MIT
compatibility: "Claude Code 2.1.251+."
description: Distributed systems patterns for locking, resilience, idempotency, and rate limiting. Use when implementing distributed locks, circuit breakers, retry policies, idempotency keys, token bucket rate limiters, or fault tolerance patterns.
tags: [distributed-systems, distributed-locks, resilience, circuit-breaker, idempotency, rate-limiting, retry, fault-tolerance, edge-computing, cloudflare-workers, vercel-edge, event-sourcing, cqrs, saga, outbox, message-queue, kafka]
context: fork
agent: backend-system-architect
version: 2.0.0
author: OrchestKit
user-invocable: false
disable-model-invocation: true
complexity: medium
persuasion-type: reference
metadata:
  category: document-asset-creation
allowed-tools:
  - Read
  - Glob
  - Grep
  - WebFetch
  - WebSearch

Distributed Systems Patterns

Comprehensive patterns for building reliable distributed systems. Each category has individual rule files in `rules/` loaded on-demand.

Quick Reference

| Category | Rules | Impact | When to Use | |----------|-------|--------|-------------| | [Distributed Locks](#distributed-locks) | 1 | CRITICAL | Fencing tokens, owner validation; Redis/Redlock and Postgres advisory via upstream docs | | [Resilience](#resilience) | 3 | CRITICAL | Circuit breakers, retry with backoff, bulkhead isolation | | [Idempotency](#idempotency) | 1 | HIGH | Idempotency keys; dedup and database-backed storage via upstream docs | | [Rate Limiting](#rate-limiting) | 2 | HIGH | Token bucket, sliding window; SlowAPI integration via upstream docs | | [Edge Computing](#edge-computing) | 2 | HIGH | Edge workers, V8 isolates, CDN caching, geo-routing | | [Event-Driven](#event-driven) | 2 | HIGH | Event sourcing, CQRS, transactional outbox, sagas |

**Total: 11 rules across 6 categories.** Removed topics point at first-party sources in [Upstream coverage](#upstream-coverage-do-not-restate); ork-specific scars live in `references/ork-delta.md`.

Quick Start

# Redis distributed lock with Lua scripts
async with RedisLock(redis_client, "payment:order-123"):
    await process_payment(order_id)

# Circuit breaker for external APIs
@circuit_breaker(failure_threshold=5, recovery_timeout=30)
@retry(max_attempts=3, base_delay=1.0)
async def call_external_api():
    ...

# Idempotent API endpoint
@router.post("/payments")
async def create_payment(
    data: PaymentCreate,
    idempotency_key: str = Header(..., alias="Idempotency-Key"),
):
    return await idempotent_execute(db, idempotency_key, "/payments", process)

# Token bucket rate limiting
limiter = TokenBucketLimiter(redis_client, capacity=100, refill_rate=10)
if await limiter.is_allowed(f"user:{user_id}"):
    await handle_request()

Distributed Locks

Coordinate exclusive access to resources across multiple service instances.

| Rule | File | Key Pattern | |------|------|-------------| | Fencing Tokens | `rules/locks-fencing-tokens.md` | Owner validation, TTL, heartbeat extension |

Redis single-node locks, Redlock quorum, and PostgreSQL advisory locks are first-party documented; see [Upstream coverage](#upstream-coverage-do-not-restate).

Resilience

Production-grade fault tolerance for distributed systems.

| Rule | File | Key Pattern | |------|------|-------------| | Circuit Breaker | `rules/resilience-circuit-breaker.md` | CLOSED/OPEN/HALF_OPEN states, sliding window | | Retry & Backoff | `rules/resilience-retry-backoff.md` | Exponential backoff, jitter, error classification | | Bulkhead Isolation | `rules/resilience-bulkhead.md` | Semaphore tiers, rejection policies, queue depth |

Idempotency

Ensure operations can be safely retried without unintended side effects.

| Rule | File | Key Pattern | |------|------|-------------| | Idempotency Keys | `rules/idempotency-keys.md` | Deterministic hashing, Stripe-style headers |

Event-consumer dedup and database-backed idempotency storage follow the Stripe pattern; see [Upstream coverage](#upstream-coverage-do-not-restate).

Rate Limiting

Protect APIs with distributed rate limiting using Redis.

| Rule | File | Key Pattern | |------|------|-------------| | Token Bucket | `rules/ratelimit-token-bucket.md` | Redis Lua scripts, burst capacity, refill rate | | Sliding Window | `rules/ratelimit-sliding-window.md` | Sorted sets, precise counting, no boundary spikes |

SlowAPI + Redis wiring and tiered limits are first-party documented; see [Upstream coverage](#upstream-coverage-do-not-restate).

Edge Computing

Edge runtime patterns for Cloudflare Workers, Vercel Edge, and Deno Deploy.

| Rule | File | Key Pattern | |------|------|-------------| | Edge Workers | `rules/edge-workers.md` | V8 isolate constraints, Web APIs, geo-routing, auth at edge | | Edge Caching | `rules/edge-caching.md` | Cache-aside at edge, CDN headers, KV storage, stale-while-revalidate |

Event-Driven

Event sourcing, CQRS, saga orchestration, and reliable messaging patterns.

| Rule | File | Key Pattern | |------|------|-------------| | Event Sourcing | `rules/event-sourcing.md` | Event-sourced aggregates, CQRS read models, optimistic concurrency | | Event Messaging | `rules/event-messaging.md` | Transactional outbox, saga compensation, idempotent consumers |

Upstream coverage (do not restate)

These topics were removed from this skill on 2026-07-31 (wrap-plus-delta thinning) because a first-party source maintains them. Consult the source; do not re-add tutorials here. Ork-specific scars for these topics live in `references/ork-delta.md`.

| Topic | First-party source | |-------|--------------------| | Redis single-node locks, Redlock algorithm and quorum | https://redis.io/docs/latest/develop/use/patterns/distributed-locks/ | | PostgreSQL advisory locks (session and transaction level) | https://www.postgresql.org/docs/current/explicit-locking.html#ADVISORY-LOCKS | | Circuit breaker pattern, thresholds, setup and rollout guides | https: