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This article mainly introduces "what are the Java programmer Dubbo interview questions". In the daily operation, I believe many people have doubts about the Java programmer Dubbo interview questions. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful to answer the doubts of "what are the Java programmer Dubbo interview questions?" Next, please follow the editor to study!

1. Explain the reasons for using Dubbo.

Answer: because it is a Dubbo Ali open source project, many domestic Internet companies are using it and have gone through many online tests. As Java programmers, they must master it. And it uses Netty and Zookeeper internally to ensure high performance and high availability. Using Dubbo can extract the core business, as an independent service, and gradually form a stable service center, which can be used to improve business reuse and flexible expansion, so that the front-end applications can respond to the changing market demand more quickly. Most importantly, the distributed architecture can withstand a larger amount of concurrent traffic.

2. Does Dubbo need a Web container?

Answer: Dubbo does not need a Web container. If you have to use a Web container, it will only add complexity and waste resources, which is really not necessary.

3. Which service containers are built into Dubbo?

Answer: Dubbo has built-in Spring Container, Jetty Container and Log4j Container. Dubbo's service container is just a simple Main method and loads a simple Spring container to expose the service.

4. What communication framework does Dubbo use by default? is there any other choice?

Answer: Dubbo uses the Netty framework by default, which is also the recommended choice. In addition, Mina and Grizzly are integrated in the content.

5. What kind of registration center is commonly used? Is there any other choice?

Answer: it is generally recommended to use zookeeper registry, redis and so on, but it is not very recommended.

6. What serialization framework is used by default and what else is there?

Answer: Hessian serialization is used by default, and Duddo, FastJson, and Java have their own serialization.

7. What should you do if you encounter cluster fault tolerance?

Answer: it is recommended to use Failover to automatically switch when the read operation fails. By default, retry other servers twice. It is recommended to use Failfast for write operations to fail quickly. If a call fails, an error will be reported immediately.

8. Does Dubbo support service multi-protocols?

Answer: Dubbo allows you to configure multiple protocols to support different protocols on different services or multiple protocols on the same service.

9. What do you do when a service interface has multiple implementations?

Answer: when an interface has multiple implementations, it can be grouped with the group attribute, and both the provider and the consumer specify the same group.

10. How is the service available compatible with the old version?

Answer: you can use the version number (version) to transition. Multiple different versions of services are registered with the registry, and services with different version numbers do not reference each other. This is a bit similar to the concept of service grouping.

11. Can Dubbo cache the results?

Answer: Dubbo can cache the results, and Dubbo provides declarative caching to accelerate access to popular data to reduce the amount of work users need to cache.

At this point, the study on "what are the Dubbo interview questions for Java programmers" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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