This article learn: the history of the whole 40 Dubbo face questions and answers, watching the rolling interviewer! (Many thanks!)
1. What Dubbo that?
Dubbo Alibaba open source high performance RPC-based distributed services framework for Java, has now become the Apache Foundation incubator project.
2. Why Dubbo?
Use Dubbo can be extracted out of the core business, as an independent service, and gradually form a stable service center, can be used to improve service multiplexing flexible expansion, the front-end applications to more quickly respond to changing market demands.
3, Dubbo and Spring Cloud What is the difference?
Different communication
Dubbo using RPC communications, while Spring Cloud using HTTP RESTFul manner.
Different part
4, Dubbo there are several nodes which role?
5, Dubbo what registry, there are other options use default it?
Zookeeper is recommended as a registration center, there Redis, Multicast, Simple registration center, but not recommended.
6, Dubbo, which has several configurations?
- XML configuration
- Java API Configuration
- Spring annotation configuration
7, Dubbo core configuration What?
8, in the Provider can configure the properties of Consumer end what?
- timeout : Timeout Method Invocation
- retries : failure retry, retry the default 2
- loadbalance : load balancing algorithm, default random
- Actives : the consumer side, the maximum limit of concurrent calls
9, when the Dubbo start if the service is not available will depend on how to use?
Dubbo default checks depend on the service is available at startup, will throw an exception is unavailable, stop Spring initialization is complete, the default check = "true", you can check by close examination = "false".
10, Dubbo, which has several fault-tolerant cluster scheme, the default is what?
11, the service recommended to read and write fault-tolerant strategy is what?
Read
Recommended Failover automatically switch fails, the default retry two other servers.
Write
Recommended Failfast fail fast, fail to immediately send a call to an error.
12, Dubbo, which has several load balancing strategy, the default is what?
13, if registered more than the same services, how to specify a particular
You can configure point-environmental direct, bypassing the registration center, will serve as the interface unit, ignoring the provider registry list.
14, when a service interface to achieve a variety of how to do?
When there are multiple implementations of an interface, you can use property group to group, service providers and consumers are assigned to the same group.
15, service on the line how compatible with older versions?
You can use the version number (version) transition, a number of different versions of the service registered to the registry, the version number of different services does not refer to each other. The concept of this and a little similar service grouping.
16, Dubbo must rely on the package what?
Dubbo must rely JDK, others are optional.
17, what Dubbo management console can do?
The main management console includes: routing rules, dynamic configuration, service degradation, access control, weight adjustment, load balancing, and other management functions.
18, talk about the services exposed Dubbo process.
Dubbo will be after the Spring instances finish of the bean, when the refresh container last step release ContextRefreshEvent event notification to achieve the export method ApplicationListener of ServiceBean classes callback onApplicationEvent event methods, Dubbo calls ServiceBean parent ServiceConfig in this method, and this method truly publication services (non-asynchronous or asynchronous).
19, Dubbo stop maintaining it?
2014 began to stop maintenance over the years, 17 years to re-start maintenance, and into the Apache project.
20, Dubbo and Dubbox What is the difference?
Dubbox is the second stop maintenance Dubbo, Dubbo Dangdang do a project based on extension, such as adding a Restful service call, updating open source components.