---
title: "Blue-Green Deployment"
type: concept
tags: [devops, deployment, release-management, high-availability]
date: 2025-03-01
---

## Definition

蓝绿部署（Blue-Green Deployment）是一种零停机发布策略，维护两套相同的生产环境（蓝环境和绿环境），通过负载均衡器切换流量实现无缝部署和快速回滚。

## Architecture

```
                    Load Balancer
                         │
              ┌──────────┴──────────┐
              │                     │
           Blue Env             Green Env
         (Production)          (Staging)
              │                     │
           v1.0                v1.1 (New)
              │
         Traffic ON         Traffic OFF
```

## Deployment Flow

```
1. Blue (v1.0) serving all traffic
2. Deploy to Green (v1.1)
3. Test/Verify Green
4. Switch LB to Green
5. Blue becomes standby (or update to next version)
```

## Key Benefits

| 优势 | 描述 |
|------|------|
| 零停机 | 流量切换瞬间完成 |
| 快速回滚 | 切换回蓝色环境即可 |
| 测试完整性 | 完整生产环境测试 |
| 风险可控 | 新版本未暴露给全部用户 |

## Comparison: Blue-Green vs Canary

| 维度 | Blue-Green | Canary |
|------|-----------|--------|
| 流量切换 | 全量切换 | 渐进式 |
| 回滚速度 | 秒级 | 秒级 |
| 资源成本 | 2x | 增量 |
| 适用场景 | 关键系统 | 持续迭代 |
| 风险 | 全量暴露 | 逐步暴露 |

## In ITSM Context

在[[ITSM 2.0]]的[[Release-Management]]中，蓝绿部署是关键实践：

```
Release Management 2.0
├── Blue-Green Deployment
│   ├── 零停机发布
│   ├── 秒级回滚
│   └── 全量验证
├── Canary Release
│   ├── 渐进式发布
│   └── 实时监控
└── DevOps-integrated ITSM
    ├── CI/CD Pipeline
    └── Automated Governance
```

## Related Concepts

- [[Release-Management]] — 发布管理总框架
- [[Canary-Release]] — 金丝雀发布
- [[High-Availability]] — 高可用架构
- [[Failover]] — 故障转移
- [[Deployment-Automation]] — 部署自动化

## Sources

- [[understanding-complete-itsm]] — Blue-Green在现代ITSM中的应用