聊聊NacosNamingService的deregisterInstance

序

本文主要研究一下 NacosNamingService 的 deregisterInstance

NacosNamingService

nacos-1.1.3/client/src/main/java/com/alibaba/nacos/client/naming/NacosNamingService.java

public class NacosNamingService implements NamingService {
    private static final String DEFAULT_PORT = "8080";
    private static final long DEFAULT_HEART_BEAT_INTERVAL = TimeUnit.SECONDS.toMillis(5);

    /**
     * Each Naming instance should have different namespace.
     */
    private String namespace;

    private String endpoint;

    private String serverList;

    private String cacheDir;

    private String logName;

    private HostReactor hostReactor;

    private BeatReactor beatReactor;

    private EventDispatcher eventDispatcher;

    private NamingProxy serverProxy;

    //......

    @Override
    public void deregisterInstance(String serviceName, String ip, int port) throws NacosException {deregisterInstance(serviceName, ip, port, Constants.DEFAULT_CLUSTER_NAME);
    }

    @Override
    public void deregisterInstance(String serviceName, String groupName, String ip, int port) throws NacosException {deregisterInstance(serviceName, groupName, ip, port, Constants.DEFAULT_CLUSTER_NAME);
    }

    @Override
    public void deregisterInstance(String serviceName, String ip, int port, String clusterName) throws NacosException {deregisterInstance(serviceName, Constants.DEFAULT_GROUP, ip, port, clusterName);
    }

    @Override
    public void deregisterInstance(String serviceName, String groupName, String ip, int port, String clusterName) throws NacosException {Instance instance = new Instance();
        instance.setIp(ip);
        instance.setPort(port);
        instance.setClusterName(clusterName);

        deregisterInstance(serviceName, groupName, instance);
    }

    @Override
    public void deregisterInstance(String serviceName, Instance instance) throws NacosException {deregisterInstance(serviceName, Constants.DEFAULT_GROUP, instance);
    }

    @Override
    public void deregisterInstance(String serviceName, String groupName, Instance instance) throws NacosException {if (instance.isEphemeral()) {beatReactor.removeBeatInfo(NamingUtils.getGroupedName(serviceName, groupName), instance.getIp(), instance.getPort());
        }
        serverProxy.deregisterService(NamingUtils.getGroupedName(serviceName, groupName), instance);
    }

    //......
}

• deregisterInstance 方法对于 ephemeral 的 instance(默认是 ephemeral) 会将其 BeatInfo 从 beatReactor 中移除，然后通过 serverProxy.deregisterService 进行服务注销

BeatReactor

nacos-1.1.3/client/src/main/java/com/alibaba/nacos/client/naming/beat/BeatReactor.java

public class BeatReactor {

    private ScheduledExecutorService executorService;

    private NamingProxy serverProxy;

    public final Map<String, BeatInfo> dom2Beat = new ConcurrentHashMap<String, BeatInfo>();

    //......

    public void removeBeatInfo(String serviceName, String ip, int port) {NAMING_LOGGER.info("[BEAT] removing beat: {}:{}:{} from beat map.", serviceName, ip, port);
        BeatInfo beatInfo = dom2Beat.remove(buildKey(serviceName, ip, port));
        if (beatInfo == null) {return;}
        beatInfo.setStopped(true);
        MetricsMonitor.getDom2BeatSizeMonitor().set(dom2Beat.size());
    }

    //......

    class BeatTask implements Runnable {

        BeatInfo beatInfo;

        public BeatTask(BeatInfo beatInfo) {this.beatInfo = beatInfo;}

        @Override
        public void run() {if (beatInfo.isStopped()) {return;}
            long result = serverProxy.sendBeat(beatInfo);
            long nextTime = result > 0 ? result : beatInfo.getPeriod();
            executorService.schedule(new BeatTask(beatInfo), nextTime, TimeUnit.MILLISECONDS);
        }
    }

    //......
}

• removeBeatInfo 方法则将指定 key 从 dom2Beat 移除，标记其 stopped 为 true；BeatTask 则会先判断是否为 stopped，否的话则通过 serverProxy.sendBeat 发送心跳信息，计算下一次调度的时间，往 executorService 添加调度任务

NamingProxy

nacos-1.1.3/client/src/main/java/com/alibaba/nacos/client/naming/net/NamingProxy.java

public class NamingProxy {

    private static final int DEFAULT_SERVER_PORT = 8848;

    private int serverPort = DEFAULT_SERVER_PORT;

    private String namespaceId;

    private String endpoint;

    private String nacosDomain;

    private List<String> serverList;

    private List<String> serversFromEndpoint = new ArrayList<String>();

    private long lastSrvRefTime = 0L;

    private long vipSrvRefInterMillis = TimeUnit.SECONDS.toMillis(30);

    private Properties properties;

    //......

    public void deregisterService(String serviceName, Instance instance) throws NacosException {NAMING_LOGGER.info("[DEREGISTER-SERVICE] {} deregistering service {} with instance: {}",
            namespaceId, serviceName, instance);

        final Map<String, String> params = new HashMap<String, String>(8);
        params.put(CommonParams.NAMESPACE_ID, namespaceId);
        params.put(CommonParams.SERVICE_NAME, serviceName);
        params.put(CommonParams.CLUSTER_NAME, instance.getClusterName());
        params.put("ip", instance.getIp());
        params.put("port", String.valueOf(instance.getPort()));
        params.put("ephemeral", String.valueOf(instance.isEphemeral()));

        reqAPI(UtilAndComs.NACOS_URL_INSTANCE, params, HttpMethod.DELETE);
    }

    //......
}

• NamingProxy 的 deregisterService 方法会往 /instance 接口发送 DELETE 请求进行服务注销

小结

NacosNamingService 的 deregisterInstance 方法对于 ephemeral 的 instance(默认是 ephemeral) 会将其 BeatInfo 从 beatReactor 中移除，然后通过 serverProxy.deregisterService 进行服务注销

doc

• NacosNamingService