high-availability

这是一个通用的实现高可用的工具, 可以通过此工具非常简便的实现高可用, 只要实现一个接口接可以, 此工具主要源于flink高可用模块，参考并稍做改动而成。 其中主要技术为利用zookeeper/Curator 进行实现高可用.

使用方法

##引用依赖

<repository>
    <id>mvn-repo</id>
    <url>https://github.com/zhaoyunhai1216/mvn-repo/master</url>
    <snapshots>
        <enabled>true</enabled>
        <updatePolicy>always</updatePolicy>
    </snapshots>
</repository>

<dependency>
    <groupId>org.selins</groupId>
    <artifactId>high-availability</artifactId>
    <version>0.1.0</version>
</dependency>

#如果以上引用不好用,可以自行下载编译

##实现方法

//接口实现
public class HighAvailabilityTest implements HighAvailability {
    HighAvailabilityServer server;
    String endpointId;

    public HighAvailabilityTest(HighAvailabilityService service, String endpointId) {
        this.endpointId = endpointId;
        server = service.startServer(this,endpointId);
    }


    public void isLeader(UUID leaderSessionID) {
        //TODO
        server.confirmLeader(leaderSessionID);
    }


    public void notLeader() {
        //TODO
    }


    public String getAddress() {
        return UUID.randomUUID().toString();
    }


    public void handleError(Exception exception) {
        //TODO
    }
}

//调用样例
Configuration configuration = new Configuration();
configuration.setValue(ConfigOptions.HA_ZOOKEEPER_QUORUM,"127.0.0.1:2181/selins");
HighAvailabilityService service = new HighAvailabilityService(configuration);
HighAvailabilityTest entry = new HighAvailabilityTest(service,"test"); 

##查询leader方法

//查询监听
public class HighAvailabilityListener implements LeaderSelector {
    @Override
    public void notifyLeaderAddress(
            String leaderAddress, //leader连接地址
            String leaderSessionID, // leader session ID
            Throwable throwable) {
        //todo
        System.out.println(leaderAddress);
    }
}

//调用样例
Configuration configuration = new Configuration();
configuration.setValue(ConfigOptions.HA_ZOOKEEPER_QUORUM,"127.0.0.1:2181/selins");
HighAvailabilityService service = new HighAvailabilityService(configuration);
SelectorServer selectorServer = service.startSelector(new HighAvailabilityListener(),"test");
System.out.println(selectorServer.lastLeaderAddress());