聊聊nacos-ServiceManager的UpdatedServiceProcessor

序

本文主要研究一下 nacos ServiceManager 的 UpdatedServiceProcessor

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_UPDATE_EXECUTOR 提交了 UpdatedServiceProcessor 任务

UpdatedServiceProcessor

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

    private class UpdatedServiceProcessor implements Runnable {
        //get changed service from other server asynchronously
        @Override
        public void run() {
            ServiceKey serviceKey = null;

            try {while (true) {
                    try {serviceKey = toBeUpdatedServicesQueue.take();
                    } catch (Exception e) {Loggers.EVT_LOG.error("[UPDATE-DOMAIN] Exception while taking item from LinkedBlockingDeque.");
                    }

                    if (serviceKey == null) {continue;}
                    GlobalExecutor.submitServiceUpdate(new ServiceUpdater(serviceKey));
                }
            } catch (Exception e) {Loggers.EVT_LOG.error("[UPDATE-DOMAIN] Exception while update service: {}", serviceKey, e);
            }
        }
    }

• UpdatedServiceProcessor 实现了 Runnable 方法，其 run 方法会不断循环从 toBeUpdatedServicesQueue 获取元素，然后使用 GlobalExecutor.submitServiceUpdate 提交 ServiceUpdater

ServiceUpdater

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

    private class ServiceUpdater implements Runnable {

        String namespaceId;
        String serviceName;
        String serverIP;

        public ServiceUpdater(ServiceKey serviceKey) {this.namespaceId = serviceKey.getNamespaceId();
            this.serviceName = serviceKey.getServiceName();
            this.serverIP = serviceKey.getServerIP();}

        @Override
        public void run() {
            try {updatedHealthStatus(namespaceId, serviceName, serverIP);
            } catch (Exception e) {Loggers.SRV_LOG.warn("[DOMAIN-UPDATER] Exception while update service: {} from {}, error: {}",
                    serviceName, serverIP, e);
            }
        }
    }

• ServiceUpdater 实现了 Runnable 接口，其 run 方法执行的是 updatedHealthStatus

ServiceManager.updatedHealthStatus

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();

    //......

    public void updatedHealthStatus(String namespaceId, String serviceName, String serverIP) {Message msg = synchronizer.get(serverIP, UtilsAndCommons.assembleFullServiceName(namespaceId, serviceName));
        JSONObject serviceJson = JSON.parseObject(msg.getData());

        JSONArray ipList = serviceJson.getJSONArray("ips");
        Map<String, String> ipsMap = new HashMap<>(ipList.size());
        for (int i = 0; i < ipList.size(); i++) {String ip = ipList.getString(i);
            String[] strings = ip.split("_");
            ipsMap.put(strings[0], strings[1]);
        }

        Service service = getService(namespaceId, serviceName);

        if (service == null) {return;}

        boolean changed = false;

        List<Instance> instances = service.allIPs();
        for (Instance instance : instances) {boolean valid = Boolean.parseBoolean(ipsMap.get(instance.toIPAddr()));
            if (valid != instance.isHealthy()) {
                changed = true;
                instance.setHealthy(valid);
                Loggers.EVT_LOG.info("{} {SYNC} IP-{} : {}@{}{}",
                    serviceName, (instance.isHealthy() ? "ENABLED" : "DISABLED"),
                    instance.getIp(), instance.getPort(), instance.getClusterName());
            }
        }

        if (changed) {pushService.serviceChanged(service);
        }

        StringBuilder stringBuilder = new StringBuilder();
        List<Instance> allIps = service.allIPs();
        for (Instance instance : allIps) {stringBuilder.append(instance.toIPAddr()).append("_").append(instance.isHealthy()).append(",");
        }

        if (changed && Loggers.EVT_LOG.isDebugEnabled()) {Loggers.EVT_LOG.debug("[HEALTH-STATUS-UPDATED] namespace: {}, service: {}, ips: {}",
                service.getNamespaceId(), service.getName(), stringBuilder.toString());
        }

    }

    //......
}

• updatedHealthStatus 方法会从 synchronizer 获取 msg，组装 ipsMap，之后通过 service.allIPs() 获取 instances 信息，然后遍历 instances 从 ipsMap 获取实例的 valid 状态，如果与 instance 的 isHealthy() 对不上则标记为 changed，更新 instance 的 healthy；对于 changed 的则通过 pushService.serviceChanged(service) 发布事件，最后打印日志

小结

• ServiceManager 的 init 方法往 UtilsAndCommons.SERVICE_UPDATE_EXECUTOR 提交了 UpdatedServiceProcessor 任务
• UpdatedServiceProcessor 实现了 Runnable 方法，其 run 方法会不断循环从 toBeUpdatedServicesQueue 获取元素，然后使用 GlobalExecutor.submitServiceUpdate 提交 ServiceUpdater
• ServiceUpdater 实现了 Runnable 接口，其 run 方法执行的是 updatedHealthStatus

doc

• ServiceManager