2nd/10_Wiki/Topics/Architecture/마이크로서비스 아키텍처의 의존성 관리.md

---
id: wiki-2026-0508-마이크로서비스-아키텍처의-의존성-관리
title: 마이크로서비스 아키텍처의 의존성 관리
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [Microservice Dependency Management, Service Dependencies, MSA 의존성]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [microservices, architecture, dependency-management, distributed-systems]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: Go
  framework: gRPC/Kubernetes
---

# 마이크로서비스 아키텍처의 의존성 관리

## 매 한 줄
> **"매 service 간 coupling 의 minimize, 매 explicit contract 의 enforce."**. 매 monolith 의 internal call 의 network call 의 transform 의 후, 매 transitive dependency · version skew · cascading failure 의 새로운 challenge 의 emerge. 2026 modern stack 은 매 OpenAPI/Protobuf contract + service mesh (Istio/Linkerd) + 매 SBOM-driven dependency tracking 의 combine.

## 매 핵심

### 매 dependency 의 종류
- **Build-time**: 매 shared library 의 dependency (avoid — leads to coordinated deploys).
- **Runtime sync**: 매 HTTP/gRPC call 의 직접 의존 (latency · failure propagation).
- **Runtime async**: 매 event/queue 의 통한 loose coupling (Kafka, NATS).
- **Data**: 매 shared DB schema 의 의존 (anti-pattern — own your data).

### 매 핵심 원칙
- **Bounded context**: 매 서비스 의 own 의 data + 매 logic 의 own.
- **Explicit contract**: 매 OpenAPI/gRPC schema 의 source-of-truth.
- **Backward compatibility**: 매 N-2 version 의 support.
- **Failure isolation**: 매 circuit breaker · timeout · bulkhead.

### 매 응용
1. 매 dependency graph 의 visualize (Backstage, Grafana service map).
2. 매 contract testing 의 CI integration (Pact, Schemathesis).
3. 매 chaos engineering 의 통한 cascading failure 의 test.

## 💻 패턴

### Circuit Breaker (Go, gobreaker)
```go
import "github.com/sony/gobreaker"

cb := gobreaker.NewCircuitBreaker(gobreaker.Settings{
    Name:        "payment-service",
    MaxRequests: 3,
    Interval:    60 * time.Second,
    Timeout:     30 * time.Second,
    ReadyToTrip: func(c gobreaker.Counts) bool {
        return c.ConsecutiveFailures > 5
    },
})

result, err := cb.Execute(func() (interface{}, error) {
    return paymentClient.Charge(ctx, req)
})
```

### gRPC contract via Protobuf
```proto
syntax = "proto3";
package payment.v1;

service PaymentService {
  rpc Charge(ChargeRequest) returns (ChargeResponse);
}

message ChargeRequest {
  string order_id = 1;
  int64 amount_cents = 2;
  string currency = 3;
}
```

### Pact consumer-driven contract test
```typescript
import { PactV3 } from "@pact-foundation/pact";

const provider = new PactV3({ consumer: "checkout", provider: "payment" });

provider
  .uponReceiving("a charge request")
  .withRequest({ method: "POST", path: "/v1/charge", body: { amount: 1000 } })
  .willRespondWith({ status: 200, body: { id: "ch_123", status: "ok" } });
```

### Async event via Kafka (decouple)
```go
producer.Send(&kafka.Message{
    Topic: "order.placed.v1",
    Value: marshal(OrderPlaced{ID: orderID, Items: items}),
})
// payment, inventory, notification 의 own pace 의 consume.
```

### Service mesh policy (Istio)
```yaml
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
spec:
  hosts: [payment]
  http:
  - timeout: 2s
    retries:
      attempts: 3
      perTryTimeout: 500ms
      retryOn: 5xx,reset,connect-failure
```

### Dependency graph extraction
```bash
# Backstage catalog scan + 매 OpenTelemetry trace 의 통한 actual call graph
otel-cli export --format=json | jq '.spans[] | {service, downstream}'
```

### SBOM for transitive deps
```bash
syft packages dir:. -o cyclonedx-json > sbom.json
grype sbom:sbom.json --fail-on high
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| Strong consistency 의 required | Sync gRPC + saga compensation |
| 매 latency-sensitive read | Sync + cache (Redis) |
| 매 cross-service workflow | Async event + saga orchestrator (Temporal) |
| Shared reference data | Read replica or 매 cached projection |
| Tight build coupling | Refactor — extract 매 shared concept 의 own service |

**기본값**: 매 async event-driven + 매 contract testing + 매 service mesh resilience.

## 🔗 Graph
- 부모: [[Microservices]] · [[Distributed Systems]]
- 변형: [[Service Mesh]] · [[Event-Driven Architecture]]
- 응용: [[Circuit_Breaker]] · [[Contract_Testing]]
- Adjacent: [[API_Versioning]] · [[Observability]]

## 🤖 LLM 활용
**언제**: 매 service decomposition 의 design, 매 dependency graph 의 review, 매 contract evolution 의 plan.
**언제 X**: 매 small monolith — 매 premature decomposition 의 cost > benefit.

## ❌ 안티패턴
- **Distributed monolith**: 매 service 의 split 의 했지만 매 deploy 의 still coordinated.
- **Shared DB**: 매 두 service 가 same table 의 write — coupling worst case.
- **Chatty API**: 매 single user action 의 N개 service call 의 fan-out.
- **No timeout**: 매 default infinite timeout — cascading hang.
- **Synchronous chain**: A → B → C → D 매 single failure 의 entire chain 의 break.

## 🧪 검증 / 중복
- Verified (Sam Newman *Building Microservices* 2nd ed, CNCF service mesh landscape 2026).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — dependency types, contract testing, mesh resilience patterns |