2nd/10_Wiki/Topic_Programming/Architecture/Service-oriented-Architecture.md

---
id: wiki-2026-0508-service-oriented-architecture
title: Service-oriented Architecture (SOA)
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [SOA, Service-oriented Architecture, 서비스 지향 아키텍처]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [architecture, soa, integration, enterprise]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: yaml
  framework: none
---

# Service-oriented Architecture (SOA)

## 매 한 줄
> **"매 비즈니스 기능을 매 reusable, network-addressable service로 매 분해"**. 2000년대 enterprise integration의 매 dominant paradigm. SOAP/WS-* + ESB로 매 시작 → REST/event-driven으로 매 진화 → 매 microservices가 매 SOA의 매 fine-grained 후속. 2026년에도 매 large enterprise (banking, telecom)에 매 살아있음.

## 매 핵심

### 매 원칙
- **Service contract**: 매 명시적 interface (WSDL, OpenAPI).
- **Loose coupling**: 매 schema/protocol 만 의존.
- **Reusability**: 매 같은 service 매 다중 consumer.
- **Composability**: 매 service 합성으로 매 process 구성.
- **Discoverability**: 매 registry (UDDI, Consul, k8s DNS).

### 매 vs Microservices
| 측면 | SOA (classic) | Microservices |
|---|---|---|
| 크기 | 매 coarse-grained (business domain) | 매 fine-grained |
| Comm | ESB + SOAP | HTTP/gRPC/Event |
| Data | 매 shared DB 가능 | DB-per-service |
| Governance | 매 central | 매 decentralized |

### 매 응용
1. 매 banking core integration.
2. 매 telecom OSS/BSS.
3. 매 government legacy modernization (SOAP wrap).
4. 매 hybrid cloud (on-prem ↔ cloud SOA bridge).

## 💻 패턴

### 매 SOAP service (Java JAX-WS)
```java
@WebService
public class OrderService {
  @WebMethod
  public OrderResponse place(@WebParam OrderRequest req) {
    return new OrderResponse("ok", req.getId());
  }
}
```

### 매 WSDL contract (요약)
```xml
<wsdl:definitions targetNamespace="http://orders.example.com">
  <wsdl:portType name="OrderService">
    <wsdl:operation name="place">
      <wsdl:input message="tns:placeRequest"/>
      <wsdl:output message="tns:placeResponse"/>
    </wsdl:operation>
  </wsdl:portType>
</wsdl:definitions>
```

### 매 ESB routing (Camel)
```java
from("activemq:queue:orders.in")
  .choice()
    .when(xpath("/order/total > 1000"))
      .to("activemq:queue:orders.high-value")
    .otherwise()
      .to("activemq:queue:orders.standard");
```

### 매 Modern REST SOA (OpenAPI)
```yaml
openapi: 3.1.0
info: { title: Orders, version: 2.0 }
paths:
  /orders:
    post:
      requestBody:
        content:
          application/json:
            schema: { $ref: "#/components/schemas/OrderRequest" }
      responses:
        "201":
          content:
            application/json:
              schema: { $ref: "#/components/schemas/Order" }
```

### 매 Service registry — Consul
```bash
consul services register -name=orders -port=8080 -address=10.0.0.5
consul catalog services
# orders, billing, inventory
```

### 매 Saga (long-running process composition)
```typescript
// 매 SOA business process orchestration
async function placeOrderSaga(order: Order) {
  await orderService.create(order);
  try {
    await paymentService.charge(order);
    await inventoryService.reserve(order);
    await shippingService.schedule(order);
  } catch (e) {
    await orderService.cancel(order.id); // 매 compensation
    throw e;
  }
}
```

### 매 BPMN/Camunda (process layer)
```xml
<bpmn:process id="OrderFulfillment">
  <bpmn:serviceTask id="charge" camunda:topic="payment-charge" />
  <bpmn:serviceTask id="reserve" camunda:topic="inventory-reserve" />
  <bpmn:serviceTask id="ship" camunda:topic="shipping-schedule" />
</bpmn:process>
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| 매 enterprise legacy 통합 | SOA + ESB 매 정당. |
| 매 cloud-native greenfield | Microservices 우선. |
| 매 strict contract + governance | SOA + WSDL/OpenAPI. |
| 매 high autonomy | Microservices + event-driven. |
| 매 long-running biz process | SOA + BPM (Camunda). |

**기본값**: 매 greenfield → microservices. 매 legacy integration → SOA.

## 🔗 Graph
- 부모: [[Distributed Systems]]
- 변형: [[Microservices]] · [[Event-Driven Architecture]] · [[ESB]]
- 응용: [[API Gateway]] · [[BPM]]
- Adjacent: [[REST]] · [[Service Mesh]] · [[Bounded_Context]]

## 🤖 LLM 활용
**언제**: 매 enterprise 통합, 매 legacy modernization 설계, 매 BPM process 디자인.
**언제 X**: 매 small startup, 매 single-team product.

## ❌ 안티패턴
- **매 ESB 매 god-object**: 매 모든 logic을 ESB로 → 매 maintenance hell.
- **매 service 가 매 DB 직접 공유**: 매 loose coupling 깨짐.
- **매 WSDL 매 micro-version 폭발**: 매 versioning 전략 부재.
- **매 SOA를 매 microservices로 매 단순 rebrand**: 매 fine-grain 차이 무시.

## 🧪 검증 / 중복
- Verified (Erl, *SOA Principles of Service Design*; Newman, *Building Microservices*).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — SOA classic + modern REST/SOA + microservices comparison |