2nd/10_Wiki/Topics/AI_and_ML/Architecture Anti-patterns.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-architecture-anti-patterns	Architecture Anti-patterns	10_Wiki/Topics	verified	self	아키텍처 안티패턴 design anti-patterns distributed monolith big ball of mud	none	B	0.9	applied	architecture anti-patterns distributed-systems microservices adr code-smell technical-debt		2026-05-10	pending	language framework language-agnostic any

Architecture Anti-patterns

📌 한 줄 통찰

"매 안 하면 좋은 것". 매 design 의 mistake catalog. 매 timeout misconfig, 매 distributed monolith, 매 big ball of mud. 매 anti-pattern 의 catalog 의 senior 의 첫 weapon.

📖 핵심

매 카테고리

Distributed system

• Distributed monolith: 매 microservice 가 sync coupling — 매 worst of both.
• Chatty service: 매 N+1 inter-service call.
• Wrong timeout: 매 too short = false fail / too long = bad UX.
• Shared database: 매 service 가 같은 DB → 매 coupling.
• No circuit breaker: 매 cascading failure.
• Synchronous chain: 매 5 service hop = 매 latency 합.

Decision-making

• Analysis paralysis: 매 fear-driven indecision.
• Forgotten decision: 매 email-only / 매 ADR 없음.
• Premature optimization: 매 evidence X 의 optimize.
• Cargo cult: 매 "Netflix 가 이렇게" 의 무비판 모방.

Code structure

• Big ball of mud: 매 boundary X.
• God object: 매 single class 의 모든 logic.
• Anaemic model: 매 entity 가 data 만 (case-by-case).
• Spaghetti: 매 control flow tangled.
• Lava flow: 매 dead code + commented-out.

Microservice 특화

• Nano-service: 매 너무 작 — 매 communication 의 logic 의 dominate.
• Entity service: 매 1 entity = 1 service (vs business capability).
• Sync everywhere: 매 async 의 부재.
• No bounded context: 매 model 의 leak.
• Versioning chaos: 매 breaking change 의 coordination X.

Data

• Data in flight: 매 in-memory 의 single source of truth.
• Eventual consistency 의 ignore: 매 user 의 see stale.
• Cache stampede: 매 expire 시 동시 fetch.
• Read-modify-write race: 매 lost update.

Sequence problem

• 매 anti-pattern 의 fix 가 매 다른 anti-pattern 의 generate.
• 매 distributed monolith 의 fix → 매 chatty / 매 sync chain.
• 매 god object 의 split → 매 nano-service.

→ 매 trade-off awareness 의 핵심.

매 detect 방법

• Architecture test: dependency-cruiser, ArchUnit.
• Dependency graph: 매 cycle / 매 hub.
• Latency analysis: 매 hop count.
• Code metric: 매 cyclomatic / 매 LOC / 매 fan-out.
• Tracing: 매 distributed trace 의 path.
• Postmortem catalog: 매 incident pattern.

매 modern catalog

• Mark Richards 의 "Software Architecture: The Hard Parts".
• Sam Newman 의 "Building Microservices".
• Vaughn Vernon "Implementing DDD".
• AWS / Azure architecture pattern.

💻 패턴 (응용 — detection / fix)

Architecture test

// .dependency-cruiser.js
module.exports = {
  forbidden: [
    {
      name: 'no-domain-to-infrastructure',
      severity: 'error',
      from: { path: '^src/domain' },
      to: { path: '^src/infrastructure' },
    },
    {
      name: 'no-circular',
      severity: 'error',
      from: {},
      to: { circular: true },
    },
  ],
};

ADR (Architecture Decision Record) template

# ADR-0042: Use Kafka for inter-service events

## Status
Accepted (2026-05-10)

## Context
3 services (order, billing, inventory) need to coordinate.
Sync HTTP creates cascading failure risk.

## Decision
Adopt Kafka for async event-driven coordination.
Use Avro for schema evolution.

## Consequences
+ Decoupling, scale, replay.
- Operational complexity (Kafka cluster).
- Debugging async harder.

## Alternatives considered
1. RabbitMQ — simpler but less throughput.
2. SQS — vendor lock-in.
3. Sync HTTP — original problem.

Circuit breaker (anti-pattern fix)

class CircuitBreaker {
  state: 'closed' | 'open' | 'half-open' = 'closed';
  failures = 0;
  lastFailure = 0;
  
  async call<T>(fn: () => Promise<T>): Promise<T> {
    if (this.state === 'open') {
      if (Date.now() - this.lastFailure > 30_000) this.state = 'half-open';
      else throw new CircuitOpen();
    }
    try {
      const result = await fn();
      if (this.state === 'half-open') this.state = 'closed';
      this.failures = 0;
      return result;
    } catch (e) {
      this.failures++;
      this.lastFailure = Date.now();
      if (this.failures > 5) this.state = 'open';
      throw e;
    }
  }
}

Detect distributed monolith

def detect_distributed_monolith(services, traces):
    """매 sync coupling chain 의 detect"""
    for trace in traces:
        sync_chain = [s for s in trace.spans if s.kind == 'sync']
        if len(sync_chain) > 3:
            yield ('long sync chain', trace.id, sync_chain)
    
    # 매 deploy coupling
    deploy_pairs = collections.Counter()
    for incident in incidents:
        if len(incident.affected_services) > 1:
            for pair in combinations(incident.affected_services, 2):
                deploy_pairs[pair] += 1
    
    return deploy_pairs.most_common(5)

🤔 결정 기준

안티패턴	해결
Distributed monolith	Async event + bounded context
Wrong timeout	Tiered timeout + circuit breaker
Forgotten decision	ADR + central wiki
Analysis paralysis	Last responsible moment + spike
God object	Refactor by responsibility
Nano-service	Merge by business capability
Cache stampede	Probabilistic refresh, lock

기본값: 매 ADR + architecture test + tracing + postmortem.

🔗 Graph

• 부모: Software Architecture Styles
• 변형: Big-Ball-of-Mud · Distributed-Monolith · Anaemic Domain Model · God-Object
• 응용: Circuit-Breaker · ADR · Bounded Context
• Adjacent: Technical_Debt · Code Smells · Refactoring_Best_Practices · Postmortem

🤖 LLM 활용

언제: 매 architecture review. 매 design decision. 매 incident 의 root cause analysis. 언제 X: 매 simple project (대부분 의 anti-pattern 의 N/A).

❌ 안티패턴 (meta)

• 모든 anti-pattern 의 fix: 매 trade-off 의 ignore.
• Cargo cult: 매 "최선" 의 context 의 ignore.
• No ADR: 매 future-self 의 confusion.
• Architecture astronaut: 매 over-design.
• YAGNI 의 무시: 매 future hypothetical 의 design.

🧪 검증 / 중복

• Verified (Mark Richards, Sam Newman, AWS Well-Architected).
• 신뢰도 B.
• Related: Software Architecture Styles · Anaemic Domain Model · Circuit-Breaker.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — 카테고리 + 매 distributed / decision / data + ADR + circuit breaker