What is the implementation principle of dubbo?

The main aspects of Dubbo’s implementation primarily include:

1. Service Registration and Discovery: Dubbo uses a registry center for registering and discovering services. Providers register their service information with the registry center upon startup and periodically send heartbeats. Consumers retrieve a list of provider addresses from the registry center when they need to call a service and select one provider to call based on a load balancing strategy.
2. Remote communication: Dubbo supports various remote communication protocols, including Dubbo protocol, HTTP protocol, RMI protocol, etc. Service providers and consumers communicate over the network, with Dubbo using the Netty framework at the underlying level to facilitate network transmission. Call information is transferred through serialization and deserialization.
3. Load balancing: Dubbo offers multiple load balancing strategies, including random, round-robin, and least active. When consumers invoke a service, they choose an available service provider based on the load balancing strategy. Through load balancing, high availability and performance optimization of services can be achieved.
4. Cluster fault tolerance: Dubbo offers various cluster fault tolerance strategies, such as failure retry, failure switch, and failure fast return. By using these strategies, automatic fault tolerance processing can be performed in the event of service call failures, increasing the reliability and stability of the system.
5. Dynamic proxy: Dubbo utilizes dynamic proxy to achieve remote service invocation. When a service consumer starts, a proxy class is generated through dynamic proxy, and the call information is encapsulated into an Invocation object. The proxy class sends the Invocation object to the service provider, who processes it accordingly and returns the result to the consumer.

In general, Dubbo achieves service registration and discovery through the registry center, service invocation through remote communication, and improves system availability and performance through load balancing and clustering fault tolerance strategies. Additionally, Dubbo simplifies remote calls using dynamic proxies, allowing developers to call remote services as if they were calling local methods.