Zookeeper
介绍
ZooKeeper是一个分布式的,开放源码的分布式应用程序协调服务,是Google的Chubby一个开源的实现,是Hadoop和Hbase的重要组件。它是一个为分布式应用提供一致性服务的软件,提供的功能包括:配置维护、域名服务、分布式同步、组服务等。(来自于百度百科)
Win安装调试
下载地址:https://www.apache.org/dyn/closer.cgi/zookeeper/
运行的地址是bin/zkServer.cmd
在你执行启动脚本之前,还有几个基本的配置项需要配置一下,Zookeeper 的配置文件在 conf 目录下,这个目录下有 zoo_sample.cfg 和 log4j.properties,你需要做的就是将 zoo_sample.cfg 改名为 zoo.cfg,因为 Zookeeper 在启动时会找这个文件作为默认配置文件。下面详细介绍一下,这个配置文件中各个配置项的意义。
# The number of milliseconds of each tick tickTime=2000 # The number of ticks that the initial # synchronization phase can take initLimit=10 # The number of ticks that can pass between # sending a request and getting an acknowledgement syncLimit=5 # the directory where the snapshot is stored. # do not use /tmp for storage, /tmp here is just # example sakes. dataDir=/tmp/zookeeper # the port at which the clients will connect clientPort=2181 # the maximum number of client connections. # increase this if you need to handle more clients #maxClientCnxns=60 # # Be sure to read the maintenance section of the # administrator guide before turning on autopurge. # # http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance # # The number of snapshots to retain in dataDir #autopurge.snapRetainCount=3 # Purge task interval in hours # Set to "0" to disable auto purge feature #autopurge.purgeInterval=1
配置详情:
tickTime=2000 ##ZK服务器与客户端之间的心跳间隔
initLimit=10 ##集群中使用,集群中可以忍耐的心跳间隔数
syncLimit=5 ##集群中使用,请求和应答之间最长等待
dataDir=/tmp/zookeeper ##保存数据的位置。默认log也在一起
调试界面
zkui的下载地址:https://codeload.github.com/DeemOpen/zkui/zip/master
界面:
Dubbo
dubbo的组成部分分为四个:consumer(消费者),register(注册中心,即zookeeper),provider(服务者),monitor(监控中心)
项目的类图:
├―api │ └―src │ └―main │ └―java │ └―com │ └―example │ └―api │ └―api │ └―TestService ├―carFactory │ └―src │ └―main │ └―java │ └―com │ └―example │ └―factory │ │―Impl │ │ └―TestServiceImpl │ └―carFactory └―carShop └―src └―main └―java └―com └―example └―carShop
Dubbo使用ZK
<dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo</artifactId> <version>${dubbo.version}</version> </dependency> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo-dependencies-zookeeper</artifactId> <version>${dubbo.version}</version> </dependency>
服务端
简单api:
package com.example.api.api; public interface TestService { public String test(); }
服务端的xml文件
//显示在界面的标识名字 <dubbo:application name="TestService" /> //注册ZooKeeper的地址 <dubbo:registry protocol="zookeeper" address="127.0.0.1:2181" /> //启动线上日志 <dubbo:protocol accesslog="true" name="dubbo" port="20880" /> //interface和name的对应,ref的testService没有关系,主要是在consumer中使用 <dubbo:service interface="com.example.api.api.TestService" ref="testService"/> //注册到bean的,可以有两种方式1)注解。类似于@Service 2)xml文件 <!--<bean id="testService" class="com.example.factory.Impl.TestServiceImpl"/>--> //扫描的地址 <context:component-scan base-package="com.example.factory" />
Note:注册到bean的方法,可以有两种方式1)注解。类似于@Service 2)xml文件
服务端提供:
public class TestServiceImpl implements TestService { public String test() { return "This a TestServiceImpl"; } }
启动服务:
public class carFactory { public static void main(String[] args){ //读取相关配置文件 ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext( "classpath*:applicationContext.xml"); context.start(); try { //卡死进程 System.in.read(); } catch (IOException e) { e.printStackTrace(); } } }
消费端
配置信息:
//显示在界面的标识名字 <dubbo:application name="TestService-consumer" /> <dubbo:registry protocol="zookeeper" address="127.0.0.1:2181" /> <dubbo:protocol accesslog="true" name="dubbo" port="20880" /> //消费的地址 <dubbo:reference id="testService" interface="com.example.api.api.TestService"/>
启动服务:
public class carShopApp { public static void main(String[] args){ ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); context.start(); TestService demoService = (TestService)context.getBean("testService"); System.out.println(demoService.test()); } }
Spring MVC + ZooKeeper
服务端
服务实现:
import com.example.api.api.TestService; import org.springframework.stereotype.Service; @Service public class TestServiceImpl implements TestService { public String test() { return "webapp:SpringMVC"; } }
Spring MVC 的XML配置:
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <display-name>springmvcdemo</display-name> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!--指定使用maven的resource为目标地址 --> <!--<context-param>--> <!--<param-name>contextConfigLocation</param-name>--> <!--<param-value>classpath:applicationContext.xml</param-value>--> <!--</context-param>--> <servlet> <servlet-name>provider</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value> WEB-INF/applicationContext.xml,WEB-INF/applicationContext-servlet.xml </param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>provider</servlet-name> <url-pattern>*.do</url-pattern> <!--指定匹配Url --> </servlet-mapping> <!-- 字符过滤器 --> <filter> <filter-name>Set Character Encoding</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>Set Character Encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
关于这个的改造,可以查看博客关于“Could not open ServletContext resource [/WEB-INF/applicationContext.xml]”解决方案
其他一些文件没啥太大作用
客户端
从注册中心中获取,然后去消费
@RestController @RequestMapping public class TestController { @Autowired private TestService testService; @GetMapping("/test.do") public String test(){ return testService.test(); } @GetMapping({"/test123.do"}) public String test123() { return "test123"; } }
其余的都和之前的差不多