Spring Boot集成Atomix快速入门Demo

1.什么是Atomix？

Atomix是一个能用的Java框架，用来构建高可用的分布式系统。它是基于RAFT协议的实现，为用户提供了各种原子数据结构，比如map/set/integer等，这些数据结构都可以在整个集群中共享并保证一致性，同时也提供了LeaderElection的原子对象，用来注册候选主结点、监听相关事件等的功能。

大多数分布式应用都需要一些有状态的组件来实现一致性和容错性。Atomix是一个可嵌入的库，有助于实现分布式资源的容错和一致性。

它提供了一套丰富的API，用于管理其资源，如集合、组和并发的工具。

2.代码工程

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>springboot-demo</artifactId><groupId>com.et</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>atomix</artifactId><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><atomix.version>3.1.12</atomix.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>io.atomix</groupId><artifactId>atomix</artifactId><version>${atomix.version}</version></dependency><dependency><groupId>io.atomix</groupId><artifactId>atomix-raft</artifactId><version>${atomix.version}</version></dependency></dependencies>
</project>

建立集群

private static Atomix buildAtomix() {List<String> raftMembers = Collections.singletonList("node1");//创建atomixreturn Atomix.builder(AtomixCluster.class.getClassLoader()).withClusterId("my-cluster").withMemberId("node1").withHost("127.0.0.1").withPort(6789).withMembershipProvider(BootstrapDiscoveryProvider.builder().build()).withManagementGroup(RaftPartitionGroup.builder("system").withNumPartitions(1).withDataDirectory(new File(LOCAL_DATA_DIR, "system")).withMembers(raftMembers).build()).addPartitionGroup(RaftPartitionGroup.builder(groupName).withNumPartitions(raftMembers.size()).withDataDirectory(new File(LOCAL_DATA_DIR, "data")).withMembers(raftMembers).build()).build();
}

分布式Map存储

Atomix atomix = buildAtomix();
//atomix启动并加入集群
atomix.start().join();//创建atomixMap
AsyncAtomicMap<Object, Object> asyncAtomicMap = atomix.atomicMapBuilder("myCfgName").withProtocol(MultiRaftProtocol.builder(groupName).withRecoveryStrategy(Recovery.RECOVER).withMaxRetries(MAX_RETRIES).build()).withReadOnly(false).build().async();
//进行数据存储
asyncAtomicMap.put("HBLOG", "http://www.liuhaihua.cn");
//进行查询
CompletableFuture<Versioned<Object>> myBlog = asyncAtomicMap.get("HBLOG");
Versioned<Object> objectVersioned = myBlog.get();
System.out.printf("value:%s version:%s%n", objectVersioned.value(), objectVersioned.version());

选举

//Elector
AsyncLeaderElector leaderElector = atomix.leaderElectorBuilder("leader").withProtocol(MultiRaftProtocol.builder(groupName).withRecoveryStrategy(Recovery.RECOVER).withMaxRetries(MAX_RETRIES).withMaxTimeout(Duration.ofMillis(15000L)).build()).withReadOnly(false).build().async();
//获取出当前节点
Member localMember = atomix.getMembershipService().getLocalMember();
System.out.println("localMember:" + localMember.toString());
String topic = "this is a topic";
//根据某一topic选举出leader,返回的是选举为leader的节点
Leadership leadership = (Leadership) leaderElector.run(topic, localMember.toString()).get();
System.out.println("==========" + leadership);
//get leadership
Leadership topicLeadership = (Leadership) leaderElector.getLeadership(topic).get();
System.out.println("------------>" + topicLeadership);
//输出所有的topic对应的leader
Map topicLeadershipMaps = (Map) leaderElector.getLeaderships().get();
System.out.println("++++++++++++" + topicLeadershipMaps.toString());

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

https://github.com/Harries/springboot-demo

3.总结

atomix的api远不止本例中的两个，还有其他很多的api。如分布式锁、分布式事务、分布式自增id、分布式队列、分布式信息号等，这些在atomix中都有实现，详细可见atomix的类方法！更多关于atomix的相关介绍，可以在对应的github中找到： https://github.com/atomix/atomix-archive

需要注意的是：基于java的atomix现已停止维护，这里仅用作学习目的，在分布式系统中体验一下。