Foreword
Dubbo with them on and EJB, WebService almost call a remote service (or JavaBean) when there is a local interface, the same as calling a local method to call, it is good to help you achieve your bottom method parameters and remote transmission services run after the results back to return, RPC is a package
of course, this is only the most basic functions of Dubbo, which is characterized by:
- It is mainly the use of efficient network framework and serialization framework that allows for higher call between distributed service efficiency.
- The use of registry management interface address many of the services, when you want to just keep up call service registration center to ask, do not like to use the same for each service had good WebService interface calls recorded.
- Monitoring Center : Implement monitoring service running between the party and the state of the caller, but also control the priority of service, authority, weight, upper and lower, so that maintenance and management across large distributed service system more convenient.
- HA : There is a service goes down? Registry will remove the node from the list of services. Or call to? The client requests a service node to another available registry recall. Registry downtime? Registration center can achieve high availability (ZooKeeper).
- Load balancing : The soft load balancing algorithm to achieve load balancing requests for multiple nodes of the same service.
I believe many of my friends have to interview Ali is the interviewer asked the questions Dubbo, Xiao Bian here to Ali interviewer asks those questions most frequently Dubbo surface finishing out for your reference
First, what Dubbo that?
Dubbo Alibaba open-source Java-based high performance RPC (A remote call) Distributed Service Framework (SOA), providing high performance and transparency of RPC remote service call programs, services and SOA governance program.
Second, why should Dubbo?
Because Ali is an open source project, many domestic companies are using the Internet, it has been through many online test. Internal use of Netty, Zookeeper, ensures high performance and high availability.
1, Dubbo can be extracted 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.
2, a distributed architecture can withstand larger concurrent flow.
Three, Dubbo and Spring Cloud What is the difference?
1, different communication ways: Dubbo using RPC communications, while Spring Cloud using HTTP RESTFul manner.
2, the composition is not the same:
Dubbo service registry to Zookeerper, service monitoring center dubbo-monitor, no message bus service tracking, batch jobs and other components;
the Spring-Cloud service registry for the spring-cloud netflix enruka, service monitoring center spring-boot admin, there is a message bus, a data stream, service tracking, batch jobs and other components;
Four, Dubbo Web container needs it?
No, if you insist on using the Web container will only add complexity, but also a waste of resources.
Five, Dubbo built what kinds of services the container?
Container three services:
. 1, the Spring Container
2, the Jetty Container
. 3, Log4j Container
Dubbo service container is a simple Main method, and load a simple Spring container for exposed services.
Six, dubbo support any agreement, which recommended use?
1、dubbo://（推荐）
2、http://
3、rest://
4、redis://
5、memcached://
Seven, Dubbo there are several nodes which role?
1, provide: exposed services service provider
2, consumer: calling remote services service consumer
3, registry: a service registry to registry found
4, monitor: monitoring center frequency statistics service calls and call time of
5, container: run container services
Eight flowchart dubbo service registration and discovery
Nine, Dubbo what registry, there are other options use default it?
It is recommended as a zookeeper registration center, and redis, multicast, simple registration center.
Ten, Dubbo core configuration What?
Due to space reasons, not all of which show that these questions I have organized into pdf documents free to share with those friends in need, while also finishing find many spent time, a friend in need can click on the blue portal that is is available to receive a free way, I also get a curated collection Ali interview.
