COLA Architecture

Clean, Object-oriented, Layered, Adaptable Application Architecture

This project is built using the COLA architecture. COLA is a clean, object-oriented, layered, and adaptable application architecture that helps reduce system entropy in complex application scenarios and improves development and operational efficiency. Whether it's traditional layered architecture, hexagonal architecture, or onion architecture, they all advocate for business-centric design, decoupling external dependencies, and separating business complexity from technical complexity. COLA architecture integrates CQRS, DDD, SOLID and other design principles on this foundation, forming a practical and implementable application architecture. For more details, please check the WIKI.

Documentation

📚 For detailed component integration guides, please refer to the documentation:

English Documentation - Component integration guides in English
中文文档 - 中文组件集成指南

Component Structure

---
title: Alibaba COLA Application Architecture Component Diagram
---
flowchart TB
    %% Driving Adapters - Top
    subgraph ActiveAdapters[" "]
        direction LR
        RPC_CLIENT(["«Driving Adapter»<br/>RPC Client"])
        JOB{{"Job Scheduler"}}
        MQ_CONSUMER(["«Driving Adapter»<br/>MQ Consumer"])
        APP_TERMINAL(["«Driving Adapter»<br/>APP Terminal"])
    end

    %% COLA Core Components
    ADAPTER["«Adapter Layer»<br/>eden-demo-cola-adapter"]
    START["«Bootstrap»<br/>eden-demo-cola-start"]
    APP_LAYER["«Application Layer»<br/>eden-demo-cola-app"]
    CLIENT["«API Layer»<br/>eden-demo-cola-client"]
    DOMAIN["«Domain Layer»<br/>eden-demo-cola-domain"]
    INFRA["«Infrastructure Layer»<br/>eden-demo-cola-infrastructure"]

    %% Interface Nodes
    rpc((rpc))
    http((http))

    %% Driven Adapters - Bottom
    subgraph PassiveDrivers[" "]
        direction LR
        THIRD_PARTY(["«Driven Adapter»<br/>Third-party API"])
        MYSQL[("«Driven Adapter»<br/>MySQL")]
        REDIS[("«Driven Adapter»<br/>Redis")]
        MQ_PRODUCER[("«Driven Adapter»<br/>MQ")]
        ES[("«Driven Adapter»<br/>Elasticsearch")]
        MONGO[("«Driven Adapter»<br/>MongoDB")]
    end

    %% Driving Adapter Connections
    RPC_CLIENT -.->|Network Call| rpc
    rpc ---|RPC Interface| ADAPTER
    APP_TERMINAL -.->|Frontend Integration| http
    http ---|REST Interface| ADAPTER
    RPC_CLIENT -.->|Code Integration| CLIENT
    JOB <-.->|Task Scheduling| ADAPTER
    MQ_CONSUMER <-.->|Consume Messages| ADAPTER

    %% Internal Component Connections
    START --> ADAPTER
    ADAPTER -->|Inbound Adaptation, Data Assembly| APP_LAYER
    APP_LAYER -->|Implement Interface| CLIENT
    APP_LAYER -->|CQRS Commands| DOMAIN
    APP_LAYER -->|CQRS Queries| INFRA
    INFRA -.->|Dependency Inversion| DOMAIN

    %% Driven Adapter Connections
    INFRA -.->|API Call| THIRD_PARTY
    INFRA -.->|Read/Write Data| MYSQL
    INFRA -.->|Read/Write Cache| REDIS
    INFRA -.->|Produce Messages| MQ_PRODUCER
    INFRA -.->|Read/Write Index| ES
    INFRA -.->|Read/Write Data| MONGO

    %% Style Definitions
    style ADAPTER fill:#90EE90,stroke:#333,stroke-width:2px
    style START fill:#90EE90,stroke:#333,stroke-width:2px
    style APP_LAYER fill:#90EE90,stroke:#333,stroke-width:2px
    style CLIENT fill:#F0E68C,stroke:#333,stroke-width:2px
    style DOMAIN fill:#90EE90,stroke:#333,stroke-width:2px
    style INFRA fill:#90EE90,stroke:#333,stroke-width:2px
    
    style RPC_CLIENT fill:#87CEEB,stroke:#333,stroke-width:1px
    style JOB fill:#87CEEB,stroke:#333,stroke-width:1px
    style MQ_CONSUMER fill:#87CEEB,stroke:#333,stroke-width:1px
    style APP_TERMINAL fill:#87CEEB,stroke:#333,stroke-width:1px
    
    style THIRD_PARTY fill:#FFB6C1,stroke:#333,stroke-width:1px
    style MYSQL fill:#FFB6C1,stroke:#333,stroke-width:1px
    style REDIS fill:#FFB6C1,stroke:#333,stroke-width:1px
    style MQ_PRODUCER fill:#FFB6C1,stroke:#333,stroke-width:1px
    style ES fill:#FFB6C1,stroke:#333,stroke-width:1px
    style MONGO fill:#FFB6C1,stroke:#333,stroke-width:1px
    
    style rpc fill:#fff,stroke:#333
    style http fill:#fff,stroke:#333

eden-demo-cola-adapter: Adapter layer, the inbound adapter in Hexagonal Architecture.
eden-demo-cola-app: Application layer, responsible for CQRS command processing, update commands call the domain layer, query operations bypass the domain layer and directly call the infrastructure layer.
eden-demo-cola-client: API layer, provides interfaces externally as a jar package.
eden-demo-cola-domain: Domain layer, core business implementation. Unlike traditional layered architecture, it provides anti-corruption layer interfaces and does not depend on infrastructure layer technical implementations.
eden-demo-cola-infrastructure: Infrastructure layer, the outbound adapter in Hexagonal Architecture, encapsulates technical details, uses Dependency Inversion to implement the anti-corruption layer interfaces exposed by Domain.
eden-demo-cola-start: Application bootstrap entry, unified management of application configuration and delivery.

Runtime Flow

%%{init: {
  'theme': 'base',
  'themeVariables': {
    'primaryColor': '#90EE90',
    'primaryTextColor': '#000',
    'primaryBorderColor': '#333',
    'lineColor': '#333',
    'secondaryColor': '#87CEEB',
    'tertiaryColor': '#FFB6C1',
    'noteBkgColor': '#FFFACD',
    'noteTextColor': '#333',
    'noteBorderColor': '#DAA520',
    'actorBkg': '#87CEEB',
    'actorBorder': '#333',
    'actorTextColor': '#000',
    'signalColor': '#333',
    'signalTextColor': '#333'
  },
  'sequence': {
    'actorMargin': 50,
    'boxMargin': 10,
    'boxTextMargin': 5,
    'noteMargin': 10,
    'messageMargin': 35,
    'mirrorActors': true,
    'useMaxWidth': true
  }
}}%%
sequenceDiagram
    autonumber
    
    box rgb(135,206,235,0.3) Driving Adapter
        participant A as Driving Adapter
    end
    box rgb(144,238,144,0.3) COLA Application Architecture
        participant B as eden-demo-cola-adapter
        participant C as eden-demo-cola-app
        participant D as eden-demo-cola-domain
        participant E as eden-demo-cola-infrastructure
    end
    box rgb(255,182,193,0.3) Driven Adapter
        participant F as Driven Adapter
    end
    box rgb(240,230,140,0.3) Extension Point
        participant G as Extension Point
    end

    Note over A,G: Scenario 1: HTTP Data Update Request
    A->>B: 1. Send write request
    B->>C: 2. Adapter assembles DTO
    C->>C: 3. CQRS parses command parameters
    C->>G: 4. Call extension based on command (optional)
    C->>D: 5. Call domain layer
    D->>E: 6. Execute data write via anti-corruption layer
    E->>F: 7. Call underlying component for write operation
    F-->>E: 
    E-->>C: 8. Return result data
    C-->>B: 9. Assemble return data
    B-->>A: 10. Response

    Note over A,G: Scenario 2: HTTP Data Query Request
    A->>B: 11. Send read request
    B->>C: 12. Adapter assembles DTO
    C->>C: 13. CQRS parses query parameters
    C->>E: 14. Execute data read operation
    E->>F: 15. Call underlying component for read operation
    F-->>E: 
    E-->>C: 16. Return query data
    C-->>B: 17. Assemble return data
    B-->>A: 18. Response

    Note over A,G: Scenario 3: MQ Message Driven / Job Scheduled Task
    A->>B: 19. Listen for event trigger
    B->>C: 20. CQRS dispatch
    
    alt Domain Call
        C->>D: 21. Call domain layer
        D->>E: 22. Execute data write via anti-corruption layer
        E->>F: 23. Call underlying component for write operation
        F-->>E: 
        E-->>C: 24. Return update result
    else Simple Query
        C->>E: 25. Execute data read operation
        E->>F: 26. Call underlying component for read operation
        F-->>E: 
        E-->>C: 27. Return query data
    end
    
    C->>C: 28. Internal processing (ACK/Status)
    C-->>B: 29. Report processing result
    B-->>A: 30. Report result

How to Build

This project uses Maven for building. The quickest way to get started is to git clone to your local machine. To simplify unnecessary technical details, this project depends on eden-architect. Execute mvn install -T 4C in the project root directory to complete the build.

How to Run

Quick Start

This project is configured with a dev environment by default. For your convenience, all external component dependencies are disabled.

Run mvn install in the project directory (add -DskipTests parameter to skip tests).
Navigate to eden-demo-cola-start directory, execute mvn spring-boot:run or start the ColaApplication class. If successful, you'll see the Spring Boot startup screen.
A simple RestController interface is implemented in this application. Click Demo API to test.
Since frontend-backend separation is the mainstream approach, please implement pages as needed. Accessing http://localhost:8081 will redirect to a 404 page.

Configuration Tuning

Enable Service Registry and Configuration Management: We recommend using Nacos. You can refer to Nacos Quick Start for quick setup. Modify the configuration file according to your Nacos address: bootstrap-dev.yml:

spring:
  cloud:
    nacos:
      discovery: # Service Registry
        enabled: true # Disabled by default, enable as needed
      config: # Configuration Center
        enabled: true # Disabled by default, enable as needed

Modify Default Data Source: This project uses H2 in-memory database by default, with Liquibase automatically initializing SQL scripts at startup. If you're using an external MySQL database, adjust the connection information here: application-dev.yml, and remove any H2 related configurations.

spring:
#  h2: # In-memory database
#    console:
#      enabled: true # Do not enable in production
#      path: /h2-console
#      settings:
#        trace: false
#        web-allow-others: false
  datasource: # Data source management
    username: 
    password: 
    url: jdbc:mysql://host:port/schema?rewriteBatchedStatements=true&useSSL=false&useOldAliasMetadataBehavior=true&useUnicode=true&serverTimezone=GMT%2B8
    driver-class-name: com.mysql.cj.jdbc.Driver

Additionally, this project includes usage examples for common components like Redis cache, RocketMQ message queue, and ShardingSphere database sharding, all disabled by default via xxx.enabled. You can enable configurations as needed to complete component integration.

How to Deploy

FatJar Simple Deployment

Execute mvn -T 4C clean package to package into a runnable fat jar, then start with the following command:

java -Dserver.port=8081 -jar target/eden-demo-cola-start.jar

Assembly Package Deployment

Execute mvn -P assembly -T 4C clean package to create compressed packages. Copy one of the following to your desired deployment directory:

target/eden-demo-cola-start-assembly.zip
target/eden-demo-cola-start-assembly.tar.gz

After extraction, you can find startup.sh or startup.bat scripts in the bin directory. Simply run them to start.

Jib Image Deployment

Google Jib plugin allows you to build images without installing Docker.

mvn -T 4C -U package
mvn -pl eden-demo-cola-start jib:build -Djib.disableUpdateChecks=true -DskipTests

Docker Container Deployment

Build images based on Spring Boot's layered feature. Ensure Docker is properly installed, then execute:

docker build -f docker/Dockerfile -t eden-demo-cola:{tag} .

Helm Application Deployment

For application-centric deployment, we recommend using Helm to manage K8s resource descriptors. Use the following commands for installation and uninstallation:

helm install eden-demo-cola ./helm # Deploy resources
helm uninstall eden-demo-cola # Uninstall resources

Continuous Integration

CI/CD Tool Options: Jenkins, CODING, Codeup, Zadig, KubeVela

Jenkins CI

The following demonstrates continuous build and deployment using Jenkins.

CODING CI

The following demonstrates continuous build and deployment using CODING. Anchor Link

Best Practices

DDD Domain-Driven Design

This project uses RBAC (Role-Based Access Control) as an example to demonstrate how to implement DDD in COLA architecture.

Strategic Design - Bounded Context Division

The RBAC system is divided into four bounded contexts: User, Role, Permission, and Menu. Each context contains aggregate roots, gateway interfaces, and domain services. The RBAC context serves as a coordinator responsible for cross-context business orchestration.

graph TB
    subgraph User Context
        User[User Aggregate Root]
        UserGateway[User Gateway]
        UserDomainService[User Domain Service]
    end
    
    subgraph Role Context
        Role[Role Aggregate Root]
        RoleGateway[Role Gateway]
    end
    
    subgraph Permission Context
        Permission[Permission Aggregate Root]
        PermissionGateway[Permission Gateway]
    end
    
    subgraph Menu Context
        Menu[Menu Aggregate Root]
        MenuGateway[Menu Gateway]
    end
    
    subgraph RBAC Context
        RbacDomainService[RBAC Domain Service]
    end
    
    User -.->|Assign| Role
    Role -.->|Associate| Permission
    Role -.->|Associate| Menu
    RbacDomainService --> User
    RbacDomainService --> Role
    RbacDomainService --> Permission

Tactical Design

Domain Model

classDiagram
    class User {
        -Long id
        -Login login
        -Email email
        -Password password
        -UserStatus status
        +create(login, email, password) User
        +changeEmail(newEmail)
        +changePassword(currentPassword, newPassword)
        +activate()
        +lock()
        +unlock()
        +disable()
        +verifyPassword(plainPassword) boolean
        +canLogin() boolean
    }
    
    class Role {
        -Long id
        -RoleCode code
        -RoleName name
        -String description
        -RoleStatus status
        -Integer sort
        +create(code, name) Role
        +updateInfo(name, description, sort)
        +enable()
        +disable()
        +isEnabled() boolean
    }
    
    class Permission {
        -Long id
        -PermissionCode code
        -String name
        -PermissionType type
        -Long parentId
        -String description
        -Integer sort
        +create(code, name, type) Permission
        +updateInfo(name, description, sort)
        +setParent(parentId)
        +isMenuPermission() boolean
        +isButtonPermission() boolean
        +isRoot() boolean
    }
    
    class Menu {
        -Long id
        -String name
        -MenuPath path
        -String icon
        -Long parentId
        -Integer sort
        -MenuStatus status
        -String component
        +create(name, path, parentId) Menu
        +updateInfo(name, icon, sort, component)
        +updatePath(path)
        +setParent(parentId)
        +show()
        +hide()
        +isVisible() boolean
        +isRootMenu() boolean
    }
    
    class Login {
        <<Value Object>>
        -String value
        +of(value) Login
    }
    
    class Email {
        <<Value Object>>
        -String value
        +of(value) Email
    }
    
    class Password {
        <<Value Object>>
        -String value
        +of(plainPassword) Password
        +matches(plainPassword) boolean
    }
    
    class RoleCode {
        <<Value Object>>
        -String value
        +of(value) RoleCode
    }
    
    class RoleName {
        <<Value Object>>
        -String value
        +of(value) RoleName
    }
    
    class PermissionCode {
        <<Value Object>>
        -String value
        +of(value) PermissionCode
    }
    
    class MenuPath {
        <<Value Object>>
        -String value
        +of(value) MenuPath
    }
    
    User *-- Login
    User *-- Email
    User *-- Password
    Role *-- RoleCode
    Role *-- RoleName
    Permission *-- PermissionCode
    Menu *-- MenuPath
    
    User "1" -- "*" Role : Assign
    Role "1" -- "*" Permission : Associate
    Role "1" -- "*" Menu : Associate

Domain Events

sequenceDiagram
    participant App as Application Layer
    participant User as User Aggregate Root
    participant EventPublisher as Event Publisher
    participant EventHandler as Event Handler
    
    App->>User: Create User
    User->>User: Register UserCreatedEvent
    App->>User: Get Domain Events
    App->>EventPublisher: Publish Event
    EventPublisher->>EventHandler: Handle UserCreatedEvent
    EventHandler->>EventHandler: Send Welcome Email
    App->>User: Clear Domain Events

Layered Architecture

COLA Layers and DDD Mapping

graph TB
    subgraph Adapter Layer
        Controller[REST Controller]
        RpcProvider[RPC Provider]
    end
    
    subgraph Application Layer
        Service[Application Service]
        CmdExe[Command Executor]
        QryExe[Query Executor]
        Assembler[DTO Assembler]
    end
    
    subgraph Domain Layer
        Entity[Aggregate Root/Entity]
        ValueObject[Value Object]
        DomainService[Domain Service]
        DomainEvent[Domain Event]
        Gateway[Anti-corruption Layer Interface]
    end
    
    subgraph Infrastructure Layer
        GatewayImpl[Gateway Implementation]
        Mapper[Data Mapper]
        DataObject[Data Object]
        EventHandler[Event Handler]
    end
    
    Controller --> Service
    RpcProvider --> Service
    Service --> CmdExe
    Service --> QryExe
    CmdExe --> Entity
    CmdExe --> DomainService
    CmdExe --> Gateway
    QryExe --> Mapper
    Entity --> ValueObject
    Entity --> DomainEvent
    DomainService --> Gateway
    GatewayImpl -.->|Implements| Gateway
    GatewayImpl --> Mapper
    Mapper --> DataObject
    EventHandler --> DomainEvent

CQRS Command Query Separation

flowchart LR
    subgraph Input[" "]
        A1[Controller]
        A2[Controller]
    end
    
    subgraph Service[" "]
        B1[CommandService]
        B2[QueryService]
    end
    
    subgraph Executor[" "]
        C1[CmdExe]
        C2[QryExe]
    end
    
    subgraph Core[" "]
        D1[Domain]
        D2["-"]
    end
    
    subgraph Data[" "]
        E1[Gateway]
        E2[Mapper]
    end
    
    subgraph Storage[" "]
        F1[(Database)]
        F2[(Database)]
    end
    
    A1 -->|Command| B1 --> C1 --> D1 --> E1 --> F1
    A2 -->|Query| B2 --> C2 -.->|Bypass Domain| E2 --> F2
    
    style D1 fill:#90EE90,stroke:#333
    style D2 fill:#f5f5f5,stroke:#ddd,stroke-dasharray: 5 5
    style E1 fill:#90EE90,stroke:#333
    style E2 fill:#FFB6C1,stroke:#333

Type	Path	Characteristics
Command (Write)	Controller → Service → CmdExe → Domain → Gateway → DB	Goes through Domain layer, ensures business rules
Query (Read)	Controller → Service → QryExe → Mapper → DB	Bypasses Domain layer, improves performance

Code Structure

eden-demo-cola-domain/
├── user/                          # User Bounded Context
│   ├── entity/                    # Entities
│   │   ├── User.java              # User Aggregate Root
│   │   └── UserStatus.java        # User Status Enum
│   ├── valueobject/               # Value Objects
│   │   ├── Login.java             # Login Account
│   │   ├── Email.java             # Email
│   │   └── Password.java          # Password
│   ├── event/                     # Domain Events
│   │   ├── UserCreatedEvent.java  # User Created Event
│   │   └── UserEmailChangedEvent.java
│   ├── domainservice/             # Domain Services
│   │   └── UserDomainService.java
│   ├── gateway/                   # Anti-corruption Layer Interfaces
│   │   └── UserGateway.java
│   └── statemachine/              # State Machine
│       └── UserStateMachine.java
├── role/                          # Role Bounded Context
│   ├── entity/
│   │   ├── Role.java              # Role Aggregate Root
│   │   └── RoleStatus.java
│   ├── valueobject/
│   │   ├── RoleCode.java
│   │   └── RoleName.java
│   └── gateway/
│       └── RoleGateway.java
├── permission/                    # Permission Bounded Context
│   ├── entity/
│   │   ├── Permission.java        # Permission Aggregate Root
│   │   └── PermissionType.java
│   ├── valueobject/
│   │   └── PermissionCode.java
│   └── gateway/
│       └── PermissionGateway.java
├── menu/                          # Menu Bounded Context
│   ├── entity/
│   │   ├── Menu.java              # Menu Aggregate Root
│   │   └── MenuStatus.java
│   ├── valueobject/
│   │   └── MenuPath.java
│   └── gateway/
│       └── MenuGateway.java
└── rbac/                          # RBAC Cross-context Coordination
    └── domainservice/
        └── RbacDomainService.java

Design Principles

Principle	Description	Example
Aggregate Root	Entry point of an aggregate, ensures consistency within the aggregate	User, Role, Permission, Menu
Value Object	No unique identifier, equality determined by attribute values	Login, Email, Password, RoleCode
Domain Event	Records important events that occur in the domain	UserCreatedEvent, UserEmailChangedEvent
Domain Service	Handles business logic across aggregates	UserDomainService, RbacDomainService
Anti-corruption Layer	Isolates domain layer from infrastructure layer	UserGateway, RoleGateway
Dependency Inversion	Domain layer defines interfaces, infrastructure layer implements	Gateway interface and GatewayImpl implementation

Git Multi-person Collaboration Branch Management

In the era of agile development, GitFlow seems inadequate. We've developed a simple and easy-to-use workflow for the team. Anchor Link

For detailed branch management strategies, Maven version management, and agile iteration cycles, please refer to the Git Workflow.

CAT Observability Solution

Analyze the entire trace including HTTP request latency, RPC call details, Log business logs, SQL and Cache execution time through TraceId. Anchor Link

Sentinel Traffic Governance Solution

Configure flow control rules based on business load, and view interface QPS and rate limiting status at any time. Anchor Link

Arthas Online Diagnostic Tool

Use runtime probes for dynamic service discovery, out-of-the-box, allowing you to diagnose your application in low-load environments. Anchor Link

Versioning

The project version number follows the x.y.z format, where x is a numeric value starting from 0 and not limited to the 0-9 range. During the incubation phase, the first digit is fixed at 0, i.e., version numbers follow the 0.x.x format.

Incubation version: 0.0.1-SNAPSHOT
Development version: 1.0.0-SNAPSHOT
Release version: 1.0.0

Version iteration rules:

1.0.0 <> 1.0.1: Compatible
1.0.0 <> 1.1.0: Mostly compatible
1.0.0 <> 2.0.0: Incompatible

Branch Management

Due to significant architectural changes between Spring Boot 2.4.x and Spring Boot 3.0.x, we maintain branches aligned with Spring Boot versions:

2.4.x branch for Spring Boot 2.4.x, minimum JDK 8.
2.7.x branch for Spring Boot 2.7.x, minimum JDK 11.
3.5.x branch for Spring Boot 3.5.x, minimum JDK 17.
4.0.x branch for Spring Boot 4.0.x, minimum JDK 17.

Changelog

Please refer to CHANGELOG.md

Name		Name	Last commit message	Last commit date
Latest commit History 407 Commits
.github		.github
.jenkins		.jenkins
.mvn/wrapper		.mvn/wrapper
docker		docker
docs		docs
eden-demo-cola-adapter		eden-demo-cola-adapter
eden-demo-cola-app		eden-demo-cola-app
eden-demo-cola-client		eden-demo-cola-client
eden-demo-cola-domain		eden-demo-cola-domain
eden-demo-cola-infrastructure		eden-demo-cola-infrastructure
eden-demo-cola-start		eden-demo-cola-start
extra		extra
helm		helm
.dockerignore		.dockerignore
.editorconfig		.editorconfig
.gitattributes		.gitattributes
.gitignore		.gitignore
.sonarcloud.properties		.sonarcloud.properties
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README-zh-CN.md		README-zh-CN.md
README.md		README.md
SECURITY.md		SECURITY.md
build.bat		build.bat
mvnw		mvnw
mvnw.cmd		mvnw.cmd
pom.xml		pom.xml

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COLA Architecture

Documentation

Component Structure

Runtime Flow

How to Build

How to Run

Quick Start

Configuration Tuning

How to Deploy

FatJar Simple Deployment

Assembly Package Deployment

Jib Image Deployment

Docker Container Deployment

Helm Application Deployment

Continuous Integration

Jenkins CI

CODING CI

Best Practices

DDD Domain-Driven Design

Tactical Design

Layered Architecture

Code Structure

Design Principles

Git Multi-person Collaboration Branch Management

CAT Observability Solution

Sentinel Traffic Governance Solution

Arthas Online Diagnostic Tool

Versioning

Branch Management

Changelog

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