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本文主要研究一下nacos的ServiceReporter

ServiceManager.init

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/core/ServiceManager.java

@Component
@DependsOn("nacosApplicationContext")
public class ServiceManager implements RecordListener<Service> {

    /**
     * Map<namespace, Map<group::serviceName, Service>>
     */
    private Map<String, Map<String, Service>> serviceMap = new ConcurrentHashMap<>();

    private LinkedBlockingDeque<ServiceKey> toBeUpdatedServicesQueue = new LinkedBlockingDeque<>(1024 * 1024);

    private Synchronizer synchronizer = new ServiceStatusSynchronizer();

    private final Lock lock = new ReentrantLock();

    @Resource(name = "consistencyDelegate")
    private ConsistencyService consistencyService;

    @Autowired
    private SwitchDomain switchDomain;

    @Autowired
    private DistroMapper distroMapper;

    @Autowired
    private ServerListManager serverListManager;

    @Autowired
    private PushService pushService;

    private final Object putServiceLock = new Object();

    @PostConstruct
    public void init() {

        UtilsAndCommons.SERVICE_SYNCHRONIZATION_EXECUTOR.schedule(new ServiceReporter(), 60000, TimeUnit.MILLISECONDS);

        UtilsAndCommons.SERVICE_UPDATE_EXECUTOR.submit(new UpdatedServiceProcessor());

        try {
            Loggers.SRV_LOG.info("listen for service meta change");
            consistencyService.listen(KeyBuilder.SERVICE_META_KEY_PREFIX, this);
        } catch (NacosException e) {
            Loggers.SRV_LOG.error("listen for service meta change failed!");
        }
    }

    //......
}

• ServiceManager的init方法往UtilsAndCommons.SERVICE_SYNCHRONIZATION_EXECUTOR注册了ServiceReporter

ServiceReporter

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/core/ServiceManager.java

    private class ServiceReporter implements Runnable {

        @Override
        public void run() {
            try {

                Map<String, Set<String>> allServiceNames = getAllServiceNames();

                if (allServiceNames.size() <= 0) {
                    //ignore
                    return;
                }

                for (String namespaceId : allServiceNames.keySet()) {

                    ServiceChecksum checksum = new ServiceChecksum(namespaceId);

                    for (String serviceName : allServiceNames.get(namespaceId)) {
                        if (!distroMapper.responsible(serviceName)) {
                            continue;
                        }

                        Service service = getService(namespaceId, serviceName);

                        if (service == null) {
                            continue;
                        }

                        service.recalculateChecksum();

                        checksum.addItem(serviceName, service.getChecksum());
                    }

                    Message msg = new Message();

                    msg.setData(JSON.toJSONString(checksum));

                    List<Server> sameSiteServers = serverListManager.getServers();

                    if (sameSiteServers == null || sameSiteServers.size() <= 0) {
                        return;
                    }

                    for (Server server : sameSiteServers) {
                        if (server.getKey().equals(NetUtils.localServer())) {
                            continue;
                        }
                        synchronizer.send(server.getKey(), msg);
                    }
                }
            } catch (Exception e) {
                Loggers.SRV_LOG.error("[DOMAIN-STATUS] Exception while sending service status", e);
            } finally {
                UtilsAndCommons.SERVICE_SYNCHRONIZATION_EXECUTOR.schedule(this, switchDomain.getServiceStatusSynchronizationPeriodMillis(), TimeUnit.MILLISECONDS);
            }
        }
    }

• ServiceReporter实现Runnable接口，其run方法会遍历allServiceNames，取出distroMapper.responsible的serviceName，重新计算recalculateChecksum，然后添加到ServiceChecksum中，构造Message，遍历sameSiteServers使用synchronizer.send发送该消息；最后往UtilsAndCommons.SERVICE_SYNCHRONIZATION_EXECUTOR重新注册ServiceReporter

ServiceStatusSynchronizer

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/misc/ServiceStatusSynchronizer.java

public class ServiceStatusSynchronizer implements Synchronizer {
    @Override
    public void send(final String serverIP, Message msg) {
        if(serverIP == null) {
            return;
        }

        Map<String,String> params = new HashMap<String, String>(10);

        params.put("statuses", msg.getData());
        params.put("clientIP", NetUtils.localServer());


        String url = "http://" + serverIP + ":" + RunningConfig.getServerPort() + RunningConfig.getContextPath() +
                UtilsAndCommons.NACOS_NAMING_CONTEXT + "/service/status";

        if (serverIP.contains(UtilsAndCommons.IP_PORT_SPLITER)) {
            url = "http://" + serverIP + RunningConfig.getContextPath() +
                    UtilsAndCommons.NACOS_NAMING_CONTEXT + "/service/status";
        }

        try {
            HttpClient.asyncHttpPostLarge(url, null, JSON.toJSONString(params), new AsyncCompletionHandler() {
                @Override
                public Integer onCompleted(Response response) throws Exception {
                    if (response.getStatusCode() != HttpURLConnection.HTTP_OK) {
                        Loggers.SRV_LOG.warn("[STATUS-SYNCHRONIZE] failed to request serviceStatus, remote server: {}", serverIP);

                        return 1;
                    }
                    return 0;
                }
            });
        } catch (Exception e) {
            Loggers.SRV_LOG.warn("[STATUS-SYNCHRONIZE] failed to request serviceStatus, remote server: " + serverIP, e);
        }

    }

    @Override
    public Message get(String serverIP, String key) {
        if(serverIP == null) {
            return null;
        }

        Map<String,String> params = new HashMap<>(10);

        params.put("key", key);

        String result;
        try {
            if (Loggers.SRV_LOG.isDebugEnabled()) {
                Loggers.SRV_LOG.debug("[STATUS-SYNCHRONIZE] sync service status from: {}, service: {}", serverIP, key);
            }
            result = NamingProxy.reqAPI(RunningConfig.getContextPath()
                + UtilsAndCommons.NACOS_NAMING_CONTEXT + "/instance/" + "statuses", params, serverIP);
        } catch (Exception e) {
            Loggers.SRV_LOG.warn("[STATUS-SYNCHRONIZE] Failed to get service status from " + serverIP, e);
            return null;
        }

        if(result == null || result.equals(StringUtils.EMPTY)) {
            return null;
        }

        Message msg = new Message();
        msg.setData(result);

        return msg;
    }
}

• ServiceStatusSynchronizer实现了Synchronizer接口，其send方法会异步执行post请求，将statuses通知到目标server

小结

ServiceReporter实现Runnable接口，其run方法会遍历allServiceNames，取出distroMapper.responsible的serviceName，重新计算recalculateChecksum，然后添加到ServiceChecksum中，构造Message，遍历sameSiteServers使用synchronizer.send发送该消息；最后往UtilsAndCommons.SERVICE_SYNCHRONIZATION_EXECUTOR重新注册ServiceReporter

doc

• ServiceManager