- Reference dubbo Chinese official document: http://dubbo.apache.org/zh-cn/docs/user/preface/architecture.html
- Development of distributed architecture
1. Initial small-scale projects using monolithic structure, a single server deployment of multiple applications, the main focus in the ORM (object-relational model).
2. With the increase in business, data access increases began deploying multiple servers with multiple applications, big business will be split into small business module, the focus in the MVC (business development model stratified).
3. When more business, a lot of the core business can take, and you want to stabilize the core business, this time RPC (Remote Services) to become the focus.
4. All business modules call each other, the cross is very serious, this time need a registration and scheduling listening center, unified management of services, then SOA (service management solutions) become the focus
- Meaning dubbo appear
Based on the fourth point above, a much-needed service registration and discovery management center, unified management of all services. dubbo address the following requirements:
When the service rises, service URL configuration management becomes very difficult, F5 hardware load balancer single-point pressure is also growing.
At this point the need for a service registry, dynamic registration and discovery service, the service location transparency. And by getting the consumer service provider address list, to achieve load balancing soft and Failover, reduce dependence on F5 hardware load balancer, but also can reduce some of the costs.
When the further development of inter-service dependencies become wrong track complex, which even before the application can not tell which application you want to start, architects can not complete description of the application architecture relationship.
In this case, we need to draw the dependency graph is automatically between applications to help architects manage to clean up the relationship.
Then, call the growing volume of services, capacity issues on the exposed services, the number of machines needed to support the service? When the machine plus?
To solve these problems, the first step, and now you want to service calls per day, response time, all figured out, as capacity planning reference. Secondly, we must dynamically adjust the weights, on-line, the right to a machine's weight has been increased, and record changes over time in response to increase in the course until the response time threshold is reached record traffic at this time, then this views multiplied by the total capacity of the machine thrust reversers.
- dubbo architecture
Role Description:
| node | 角色说明 |
|---|---|
Provider |
暴露服务的服务提供方 |
Consumer |
调用远程服务的服务消费方 |
Registry |
服务注册与发现的注册中心 |
Monitor |
统计服务的调用次数和调用时间的监控中心 |
Container |
服务运行容器 |
调用关系说明
- 服务容器负责启动，加载，运行服务提供者。
- 服务提供者在启动时，向注册中心注册自己提供的服务。
- 服务消费者在启动时，向注册中心订阅自己所需的服务。
- 注册中心返回服务提供者地址列表给消费者，如果有变更，注册中心将基于长连接推送变更数据给消费者。
- 服务消费者，从提供者地址列表中，基于软负载均衡算法，选一台提供者进行调用，如果调用失败，再选另一台调用。
- 服务消费者和提供者，在内存中累计调用次数和调用时间，定时每分钟发送一次统计数据到监控中心。