From 750920d135f21e8c53d781b794a0f6016aff3135 Mon Sep 17 00:00:00 2001
From: wonder <hezhaohui0807@163.com>
Date: Thu, 30 Apr 2026 09:08:09 +0800
Subject: [PATCH] vault backup: 2026-04-30 09:08:09

---
 hzh/MS/02-服务治理.md | 73 +++++++++++++++++++++++++++++++++++++++----
 1 file changed, 67 insertions(+), 6 deletions(-)

diff --git a/hzh/MS/02-服务治理.md b/hzh/MS/02-服务治理.md
index cf2831a..a4d8f35 100644
--- a/hzh/MS/02-服务治理.md
+++ b/hzh/MS/02-服务治理.md
@@ -169,6 +169,49 @@ message Item {
 }
 ```
 
+### 典型请求链路
+
+一次下单操作会串联多个服务和两种通信模式：
+
+```mermaid
+sequenceDiagram
+    participant C as Client
+    participant GW as API Gateway
+    participant O as Order Service
+    participant I as Inventory Service
+    participant P as Payment Service
+    participant MQ as Message Queue
+
+    C->>GW: POST /orders (HTTP/JSON)
+    GW->>O: CreateOrder (gRPC)
+
+    rect rgb(200, 220, 250)
+        Note over O,P: 同步 RPC 链
+        O->>I: CheckStock (gRPC)
+        I-->>O: {ok: true, quantity: 1}
+        O->>P: Charge (gRPC)
+        P-->>O: {success: true}
+    end
+
+    O-->>GW: {orderId: "ORD-001"}
+    GW-->>C: 200 OK
+
+    rect rgb(255, 240, 220)
+        Note over O,MQ: 异步事件解耦
+        O->>MQ: Publish OrderCreated Event
+        MQ->>N: Consume → SendSms
+        Note right of N: 通知类场景，不阻塞主流程
+    end
+```
+
+> [!keypoint] 关键洞察
+>
+> - 同步链路（蓝色）：**gRPC 直连**，延迟低，适合核心事务（查库存 → 扣款）
+> - 异步链路（橙色）：**消息队列**，解耦非关键路径（发短信、发积分），即使失败也不影响下单主干
+> - API Gateway 负责统一鉴权和限流，下游服务之间通过 gRPC 高效通信
+>
+> 这就是「同步 RPC 保性能，异步 MQ 保解耦」的组合拳。
+
 ### 同步 vs 异步
 
 > [!question] 关键时刻的判断
@@ -232,12 +275,30 @@ func retryWithBackoff(ctx context.Context, maxRetries int, fn func() error) erro
 当下游服务频繁失败时，快速失败避免线程堆积雪崩：
 
 ```mermaid
-stateDiagram-v2
-    [*] --> Closed: "正常状态"
-    Closed --> Open: "失败率超过阈值"
-    Open --> HalfOpen: "等待探测间隔"
-    HalfOpen --> Closed: "探测成功"
-    HalfOpen --> Open: "探测失败"
+flowchart TD
+    CB{{🔘 CIRCUIT BREAKER}}
+
+    subgraph CL ["CLOSED — 正常"]
+        C["请求放行<br/>⏱ 实时统计成功率<br/>⚠️ 连续失败 → 熔断"]
+    end
+
+    subgraph OP ["OPEN — 熔断"]
+        O["🚫 请求短路<br/>💥 直接返回降级响应<br/>🛡 不调下游，防雪崩"]
+    end
+
+    subgraph HO ["HALF-OPEN — 半开"]
+        H["🔍 放行少量探测请求<br/>✅ 成功 → 恢复全量流量<br/>❌ 失败 → 重新熔断"]
+    end
+
+    CB --> CL
+    CL -.->|失败 > N| OP
+    OP -.->|等待超时| HO
+    HO -->|探测成功| CL
+    HO -->|探测失败| OP
+
+    style CL fill:#e6f9e6,stroke:#4caf50,stroke-width:3px,color:#000
+    style OP fill:#ffebee,stroke:#ef5350,stroke-width:3px,color:#000
+    style HO fill:#fff8e1,stroke:#ffa726,stroke-width:3px,color:#000
 ```
 
 ```go