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

---
id: wiki-2026-0508-architecture-anti-patterns
title: Architecture Anti-patterns
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [아키텍처 안티패턴, design anti-patterns, distributed monolith, big ball of mud]
duplicate_of: none
source_trust_level: B
confidence_score: 0.9
verification_status: applied
tags: [architecture, anti-patterns, distributed-systems, microservices, adr, code-smell, technical-debt]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: language-agnostic
  framework: 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
```js
// .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
```markdown
# 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)
```ts
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
```python
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: [[Architecture-Styles]]
- 변형: [[Big-Ball-of-Mud]] · [[Distributed-Monolith]] · [[Anaemic-Domain-Model]] · [[God-Object]]
- 응용: [[Circuit-Breaker]] · [[ADR]] · [[Bounded-Context]]
- Adjacent: [[Technical_Debt|Technical-Debt]] · [[Code-Smells]] · [[Refactoring_Best_Practices|Refactoring]] · [[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: [[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 |