实践Dubbo

Dubbo is a high-performance, java based open source RPC framework.

前言

背景

架构

配置

配置关系

1. Application：应用，可以是消费者或提供者

2. Provider：提供者，用于提供Service的默认配置，可以开放多个Protocol，可以发布到多个Registry，可以对接多个Monitor，归属某个Application

3. Consumer：消费者，用于提供Reference的默认配置，可以从多个Registry查找Service，可以对接多个Monitor，归属某个Application

4. Module：模块

5. Registry：注册中心，提供服务注册和发现，比如zookeeper、nacos等

6. Protocol：RPC协议，比如dubbo、http等

7. Monitor：监控中心

8. Service：对应于Interface的实现，可以包括多个method，可以开放多个Protocol，可以发布到多个Registry，可以对接多个Monitor，归属某个Provider

9. Reference：对应于Service的引用，可以从多个Registry查找Service，可以对接多个Monitor，归属某个Consumer

10. Method：隶属于Service，一个具体的功能方法

11. Argument：参数

优先级

设计

启动时检查

集群容错

负载均衡

线程模型

线程池

RejectedExecutionHandler为继承AbortPolicy的AbortPolicyWithReport

fixed

属性	默认值	描述
threads	200	固定线程数量，corethreads=threads
queues	0	队列长度

alive固定为0

cached

属性	默认值	描述
corethreads	0	核心线程数
threads	Integer.MAX_VALUE	最大线程数
queues	0	队列长度
alive	60*1000	冗余线程可空闲时间，单位毫秒

limited

属性	默认值	描述
corethreads	0	核心线程数
threads	200	最大线程数
queues	0	队列长度

alive固定为Long.MAX_VALUE，可以理解为线程不会被回收

eager

当corethreads用完时，优先创建线程，而不是放入队列

属性	默认值	描述
corethreads	0	核心线程数
threads	Integer.MAX_VALUE	最大线程数
queues	0	队列长度
alive	60*1000	冗余线程可空闲时间，单位毫秒

服务端

New I/O server boss #1 ([id: 0x4086d8fb, /0:0:0:0:0:0:0:0:20880])

New I/O client worker #1-1

New I/O client worker #1-2

DubboServerHandler-192.168.1.193:20880-thread-1

DubboServerHandler-192.168.1.193:20880-thread-2

客户端

New I/O client worker #1-1

DubboClientHandler-172.19.177.79:20880-thread-1

DubboClientHandler-172.19.177.79:20880-thread-2

直连提供者

路由规则

条件路由

支持以服务或应用为粒度配置路由规则

标签路由

以Provider应用为粒度配置路由规则

生态系统

脚手架

快速生成基于 Spring Boot 的 Dubbo 项目:

Dubbo Initializr

多语言

Dubbo支持以下语言:

JavaNode.jsPythonPHP

API

Dubbo支持通过多种API方式启动:

Spring XMLSpring AnnotationPlain JavaSpring Boot

Registry

Dubbo支持以下注册中心:

ZookeeperRedisSimpleMulticastEtcd3

Cluster

Dubbo支持以下容错机制:

Fail overFail safeFail fastFail backForkingBroadcast

Load balance

Dubbo支持以下负载均衡策略:

RandomLeast ActiveRound RobinConsistent hash

Protocol

Dubbo支持以下协议:

DubboRMIHessianHTTPWebServiceThriftNative ThriftMemcachedRedisRestJsonRPCXmlRPCJmsRpc

Transport

Dubbo支持以下网络传输扩展:

Netty3Netty4GrizzlyJettyMinaP2PZookeeper

Serialization

Dubbo支持以下序列化机制:

Hessian2JavaJSONFstKryoNative HessianAvro

QA

注册地址

需要配置zookeeper服务器的ip和主机名映射，Linux服务器下修改/etc/hosts。

java.net.UnknownHostException Name or service not known

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2022-06-20 16:17:41,139 ERROR [main] com.xxl.rpc.util.IpUtil [IpUtil.java : 108] service-2.novalocal: service-2.novalocal: Name or service not known java.net.UnknownHostException: service-2.novalocal: service-2.novalocal: Name or service not known at java.net.InetAddress.getLocalHost(InetAddress.java:1505) at com.xxl.rpc.util.IpUtil.getLocalAddress0(IpUtil.java:102) at com.xxl.rpc.util.IpUtil.getLocalAddress(IpUtil.java:161) at com.xxl.rpc.util.IpUtil.getIp(IpUtil.java:172) at com.xxl.job.core.executor.XxlJobExecutor.start(XxlJobExecutor.java:83) at com.xxl.job.core.executor.impl.XxlJobSpringExecutor.afterPropertiesSet(XxlJobSpringExecutor.java:42) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) at com.xxl.job.executor.XxlJobExecutorApplication.main(XxlJobExecutorApplication.java:14) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) at org.springframework.boot.loader.Launcher.launch(Launcher.java:51) at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:52) Caused by: java.net.UnknownHostException: service-2.novalocal: Name or service not known at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method) at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928) at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323) at java.net.InetAddress.getLocalHost(InetAddress.java:1500) ... 31 common frames omitted

ping hostname不通导致，在/etc/hosts添加ip和hostname的映射即可解决。