test

graph TB
    subgraph "クライアント層"
        Web[Webブラウザ]
        Mobile[モバイルアプリ]
    end

    subgraph "アプリケーション層"
        LB[Load Balancer]
        API1[API Server 1]
        API2[API Server 2]
        API3[API Server 3]
    end

    subgraph "データ層"
        Primary[(Primary DB)]
        Replica[(Replica DB)]
        Cache[(Redis Cache)]
    end

    Web --> LB
    Mobile --> LB
    LB --> API1
    LB --> API2
    LB --> API3
    API1 --> Primary
    API2 --> Primary
    API3 --> Primary
    API1 --> Cache
    API2 --> Cache
    API3 --> Cache
    Primary --> Replica

    style Primary fill:#f9f,stroke:#333,stroke-width:4px
    style LB fill:#bbf,stroke:#333,stroke-width:2px