openfeign依据consul中的服务找到对应的pod的ip：port。蓝绿怎么做？

```mermaid
flowchart TD
    subgraph Client Side
        A[Spring Boot App with OpenFeign] -->|Call my-service| B[Spring Cloud LoadBalancer]
    end

    subgraph Consul
        B -->|Query my-service instances| C[Consul Service Discovery]
        C -->|Return instances with tags/meta| D[Instance List with version info]
    end

    subgraph K8s Cluster
        D -->|Filter version=blue/green| E[Service Selector / LoadBalancer]
        
        subgraph Blue Deployment
            E --> F[Pod Blue 1]
            E --> G[Pod Blue 2]
        end

        subgraph Green Deployment
            E --> H[Pod Green 1]
            E --> I[Pod Green 2]
        end
    end

    %% Optional: Gateway / Ingress for traffic control
    subgraph Gateway/Ingress Layer
        J[Ingress / Service Mesh] -.-> E
        J -->|Route 90% blue, 10% green| F
        J -->|Route 90% blue, 10% green| H
    end
```

❓ 蓝系统weight 0，绿系统100%，但蓝系统的kafka还在消费，topic被蓝系统消费掉了，会不会产生问题？
没有问题。如果蓝绿规划为同一消费者组，并且消费是密等的，被谁消费掉无所谓。

💡 最佳实践：
1.	蓝绿切换时，不仅切换 HTTP 流量，还要 优雅下线旧版本 Kafka 消费器
2.	消费逻辑保持幂等，避免蓝绿切换引发重复处理

redis: 共享 Redis + 蓝绿系统写入隔离

mysql:

```mermaid
flowchart TD
    subgraph ClientSide
        A[HTTP_Request] -->|flow_0_percent| B[Blue_System_old_version]
        A -->|flow_100_percent| C[Green_System_new_version]
    end

    subgraph MySQLCluster
        D[(MySQL_Primary_Cluster)]
    end

    %% Blue system behavior
    B -->|finish_old_transactions| D
    B -->|use_old_schema_fields| D

    %% Green system behavior
    C -->|handle_new_requests| D
    C -->|use_new_schema_fields| D

    %% Notes
    subgraph Notes
        N1[Blue system flow 0 but finishes old transactions to ensure data consistency]
        N2[Blue/Green share MySQL, schema must be backward compatible]
        N3[Write operations should be idempotent to avoid conflicts]
    end
```