HAOGRE's blog

eureka-client-source-code

基本功能

  • 注册服务实例到Eureka Server中;
  • 发送心跳更新与Eureka Server的租约;
  • 在服务关闭时从Eureka Server中取消租约,服务下线;
  • 查询在Eureka Server中注册的服务实例列表;

    1)相关配置的赋值,类似ApplicationInfoManager、EurekaClientConfig等。

    2)备份注册中心的初始化,默认没有实现。

    3)拉取Eureka Server注册表中的信息。

    4)注册前的预处理。

    5)向Eureka Server注册自身。

    6)初始化心跳定时任务、缓存刷新和按需注册等定时任务。

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/*
* Copyright 2012 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package com.netflix.discovery;

import static com.netflix.discovery.EurekaClientNames.METRIC_REGISTRATION_PREFIX;
import static com.netflix.discovery.EurekaClientNames.METRIC_REGISTRY_PREFIX;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import javax.annotation.Nullable;
import javax.annotation.PreDestroy;
import javax.inject.Provider;
import javax.inject.Singleton;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import javax.ws.rs.core.Response.Status;

import com.netflix.discovery.shared.resolver.EndpointRandomizer;
import com.netflix.discovery.shared.resolver.ResolverUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Strings;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import com.google.inject.Inject;
import com.netflix.appinfo.ApplicationInfoManager;
import com.netflix.appinfo.HealthCheckCallback;
import com.netflix.appinfo.HealthCheckCallbackToHandlerBridge;
import com.netflix.appinfo.HealthCheckHandler;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.appinfo.InstanceInfo.ActionType;
import com.netflix.appinfo.InstanceInfo.InstanceStatus;
import com.netflix.discovery.endpoint.EndpointUtils;
import com.netflix.discovery.shared.Application;
import com.netflix.discovery.shared.Applications;
import com.netflix.discovery.shared.resolver.ClosableResolver;
import com.netflix.discovery.shared.resolver.aws.ApplicationsResolver;
import com.netflix.discovery.shared.transport.EurekaHttpClient;
import com.netflix.discovery.shared.transport.EurekaHttpClientFactory;
import com.netflix.discovery.shared.transport.EurekaHttpClients;
import com.netflix.discovery.shared.transport.EurekaHttpResponse;
import com.netflix.discovery.shared.transport.EurekaTransportConfig;
import com.netflix.discovery.shared.transport.TransportClientFactory;
import com.netflix.discovery.shared.transport.jersey.EurekaJerseyClient;
import com.netflix.discovery.shared.transport.jersey.Jersey1DiscoveryClientOptionalArgs;
import com.netflix.discovery.shared.transport.jersey.Jersey1TransportClientFactories;
import com.netflix.discovery.shared.transport.jersey.TransportClientFactories;
import com.netflix.discovery.util.ThresholdLevelsMetric;
import com.netflix.servo.annotations.DataSourceType;
import com.netflix.servo.monitor.Counter;
import com.netflix.servo.monitor.Monitors;
import com.netflix.servo.monitor.Stopwatch;

/**
* The class that is instrumental for interactions with <tt>Eureka Server</tt>.
*
* <p>
* <tt>Eureka Client</tt> is responsible for a) <em>Registering</em> the
* instance with <tt>Eureka Server</tt> b) <em>Renewal</em>of the lease with
* <tt>Eureka Server</tt> c) <em>Cancellation</em> of the lease from
* <tt>Eureka Server</tt> during shutdown
* <p>
* d) <em>Querying</em> the list of services/instances registered with
* <tt>Eureka Server</tt>
* <p>
*
* <p>
* <tt>Eureka Client</tt> needs a configured list of <tt>Eureka Server</tt>
* {@link java.net.URL}s to talk to.These {@link java.net.URL}s are typically amazon elastic eips
* which do not change. All of the functions defined above fail-over to other
* {@link java.net.URL}s specified in the list in the case of failure.
* </p>
*
* @author Karthik Ranganathan, Greg Kim
* @author Spencer Gibb
*
*/
@Singleton
public class DiscoveryClient implements EurekaClient {
private static final Logger logger = LoggerFactory.getLogger(DiscoveryClient.class);

// Constants
public static final String HTTP_X_DISCOVERY_ALLOW_REDIRECT = "X-Discovery-AllowRedirect";

private static final String VALUE_DELIMITER = ",";
private static final String COMMA_STRING = VALUE_DELIMITER;

/**
* @deprecated here for legacy support as the client config has moved to be an instance variable
*/
@Deprecated
private static EurekaClientConfig staticClientConfig;

// Timers
private static final String PREFIX = "DiscoveryClient_";
private final Counter RECONCILE_HASH_CODES_MISMATCH = Monitors.newCounter(PREFIX + "ReconcileHashCodeMismatch");
private final com.netflix.servo.monitor.Timer FETCH_REGISTRY_TIMER = Monitors
.newTimer(PREFIX + "FetchRegistry");
private final Counter REREGISTER_COUNTER = Monitors.newCounter(PREFIX
+ "Reregister");

// instance variables
/**
* A scheduler to be used for the following 3 tasks:
* - updating service urls
* - scheduling a TimedSuperVisorTask
*/
private final ScheduledExecutorService scheduler;
// additional executors for supervised subtasks
private final ThreadPoolExecutor heartbeatExecutor;
private final ThreadPoolExecutor cacheRefreshExecutor;

private final Provider<HealthCheckHandler> healthCheckHandlerProvider;
private final Provider<HealthCheckCallback> healthCheckCallbackProvider;
private final PreRegistrationHandler preRegistrationHandler;
private final AtomicReference<Applications> localRegionApps = new AtomicReference<Applications>();
private final Lock fetchRegistryUpdateLock = new ReentrantLock();
// monotonically increasing generation counter to ensure stale threads do not reset registry to an older version
private final AtomicLong fetchRegistryGeneration;
private final ApplicationInfoManager applicationInfoManager;
private final InstanceInfo instanceInfo;
private final AtomicReference<String> remoteRegionsToFetch;
private final AtomicReference<String[]> remoteRegionsRef;
private final InstanceRegionChecker instanceRegionChecker;

private final EndpointUtils.ServiceUrlRandomizer urlRandomizer;
private final EndpointRandomizer endpointRandomizer;
private final Provider<BackupRegistry> backupRegistryProvider;
private final EurekaTransport eurekaTransport;

private final AtomicReference<HealthCheckHandler> healthCheckHandlerRef = new AtomicReference<>();
private volatile Map<String, Applications> remoteRegionVsApps = new ConcurrentHashMap<>();
private volatile InstanceInfo.InstanceStatus lastRemoteInstanceStatus = InstanceInfo.InstanceStatus.UNKNOWN;
private final CopyOnWriteArraySet<EurekaEventListener> eventListeners = new CopyOnWriteArraySet<>();

private String appPathIdentifier;
private ApplicationInfoManager.StatusChangeListener statusChangeListener;

private InstanceInfoReplicator instanceInfoReplicator;

private volatile int registrySize = 0;
private volatile long lastSuccessfulRegistryFetchTimestamp = -1;
private volatile long lastSuccessfulHeartbeatTimestamp = -1;
private final ThresholdLevelsMetric heartbeatStalenessMonitor;
private final ThresholdLevelsMetric registryStalenessMonitor;

private final AtomicBoolean isShutdown = new AtomicBoolean(false);

protected final EurekaClientConfig clientConfig;
protected final EurekaTransportConfig transportConfig;

private final long initTimestampMs;

private static final class EurekaTransport {
private ClosableResolver bootstrapResolver;
private TransportClientFactory transportClientFactory;

private EurekaHttpClient registrationClient;
private EurekaHttpClientFactory registrationClientFactory;

private EurekaHttpClient queryClient;
private EurekaHttpClientFactory queryClientFactory;

void shutdown() {
if (registrationClientFactory != null) {
registrationClientFactory.shutdown();
}

if (queryClientFactory != null) {
queryClientFactory.shutdown();
}

if (registrationClient != null) {
registrationClient.shutdown();
}

if (queryClient != null) {
queryClient.shutdown();
}

if (transportClientFactory != null) {
transportClientFactory.shutdown();
}

if (bootstrapResolver != null) {
bootstrapResolver.shutdown();
}
}
}

public static class DiscoveryClientOptionalArgs extends Jersey1DiscoveryClientOptionalArgs {

}

/**
* Assumes applicationInfoManager is already initialized
*
* @deprecated use constructor that takes ApplicationInfoManager instead of InstanceInfo directly
*/
@Deprecated
public DiscoveryClient(InstanceInfo myInfo, EurekaClientConfig config) {
this(myInfo, config, null);
}

/**
* Assumes applicationInfoManager is already initialized
*
* @deprecated use constructor that takes ApplicationInfoManager instead of InstanceInfo directly
*/
@Deprecated
public DiscoveryClient(InstanceInfo myInfo, EurekaClientConfig config, DiscoveryClientOptionalArgs args) {
this(ApplicationInfoManager.getInstance(), config, args);
}

/**
* @deprecated use constructor that takes ApplicationInfoManager instead of InstanceInfo directly
*/
@Deprecated
public DiscoveryClient(InstanceInfo myInfo, EurekaClientConfig config, AbstractDiscoveryClientOptionalArgs args) {
this(ApplicationInfoManager.getInstance(), config, args);
}

public DiscoveryClient(ApplicationInfoManager applicationInfoManager, EurekaClientConfig config) {
this(applicationInfoManager, config, null);
}

/**
* @deprecated use the version that take {@link com.netflix.discovery.AbstractDiscoveryClientOptionalArgs} instead
*/
@Deprecated
public DiscoveryClient(ApplicationInfoManager applicationInfoManager, final EurekaClientConfig config, DiscoveryClientOptionalArgs args) {
this(applicationInfoManager, config, (AbstractDiscoveryClientOptionalArgs) args);
}

public DiscoveryClient(ApplicationInfoManager applicationInfoManager, final EurekaClientConfig config, AbstractDiscoveryClientOptionalArgs args) {
this(applicationInfoManager, config, args, ResolverUtils::randomize);
}

public DiscoveryClient(ApplicationInfoManager applicationInfoManager, final EurekaClientConfig config, AbstractDiscoveryClientOptionalArgs args, EndpointRandomizer randomizer) {
this(applicationInfoManager, config, args, new Provider<BackupRegistry>() {
private volatile BackupRegistry backupRegistryInstance;

@Override
public synchronized BackupRegistry get() {
if (backupRegistryInstance == null) {
String backupRegistryClassName = config.getBackupRegistryImpl();
if (null != backupRegistryClassName) {
try {
backupRegistryInstance = (BackupRegistry) Class.forName(backupRegistryClassName).newInstance();
logger.info("Enabled backup registry of type {}", backupRegistryInstance.getClass());
} catch (InstantiationException e) {
logger.error("Error instantiating BackupRegistry.", e);
} catch (IllegalAccessException e) {
logger.error("Error instantiating BackupRegistry.", e);
} catch (ClassNotFoundException e) {
logger.error("Error instantiating BackupRegistry.", e);
}
}

if (backupRegistryInstance == null) {
logger.warn("Using default backup registry implementation which does not do anything.");
backupRegistryInstance = new NotImplementedRegistryImpl();
}
}

return backupRegistryInstance;
}
}, randomizer);
}

/**
* @deprecated Use {@link #DiscoveryClient(ApplicationInfoManager, EurekaClientConfig, AbstractDiscoveryClientOptionalArgs, Provider<BackupRegistry>, EndpointRandomizer)}
*/
@Deprecated
DiscoveryClient(ApplicationInfoManager applicationInfoManager, EurekaClientConfig config, AbstractDiscoveryClientOptionalArgs args,
Provider<BackupRegistry> backupRegistryProvider) {
this(applicationInfoManager, config, args, backupRegistryProvider, ResolverUtils::randomize);
}

@Inject
DiscoveryClient(ApplicationInfoManager applicationInfoManager, EurekaClientConfig config, AbstractDiscoveryClientOptionalArgs args,
Provider<BackupRegistry> backupRegistryProvider, EndpointRandomizer endpointRandomizer) {
if (args != null) {
this.healthCheckHandlerProvider = args.healthCheckHandlerProvider;
this.healthCheckCallbackProvider = args.healthCheckCallbackProvider;
this.eventListeners.addAll(args.getEventListeners());
this.preRegistrationHandler = args.preRegistrationHandler;
} else {
this.healthCheckCallbackProvider = null;
this.healthCheckHandlerProvider = null;
this.preRegistrationHandler = null;
}

this.applicationInfoManager = applicationInfoManager;
InstanceInfo myInfo = applicationInfoManager.getInfo();

clientConfig = config;
staticClientConfig = clientConfig;
transportConfig = config.getTransportConfig();
instanceInfo = myInfo;
if (myInfo != null) {
appPathIdentifier = instanceInfo.getAppName() + "/" + instanceInfo.getId();
} else {
logger.warn("Setting instanceInfo to a passed in null value");
}

this.backupRegistryProvider = backupRegistryProvider;
this.endpointRandomizer = endpointRandomizer;
this.urlRandomizer = new EndpointUtils.InstanceInfoBasedUrlRandomizer(instanceInfo);
localRegionApps.set(new Applications());

fetchRegistryGeneration = new AtomicLong(0);

remoteRegionsToFetch = new AtomicReference<String>(clientConfig.fetchRegistryForRemoteRegions());
remoteRegionsRef = new AtomicReference<>(remoteRegionsToFetch.get() == null ? null : remoteRegionsToFetch.get().split(","));

if (config.shouldFetchRegistry()) {
this.registryStalenessMonitor = new ThresholdLevelsMetric(this, METRIC_REGISTRY_PREFIX + "lastUpdateSec_", new long[]{15L, 30L, 60L, 120L, 240L, 480L});
} else {
this.registryStalenessMonitor = ThresholdLevelsMetric.NO_OP_METRIC;
}

if (config.shouldRegisterWithEureka()) {
this.heartbeatStalenessMonitor = new ThresholdLevelsMetric(this, METRIC_REGISTRATION_PREFIX + "lastHeartbeatSec_", new long[]{15L, 30L, 60L, 120L, 240L, 480L});
} else {
this.heartbeatStalenessMonitor = ThresholdLevelsMetric.NO_OP_METRIC;
}

logger.info("Initializing Eureka in region {}", clientConfig.getRegion());

if (!config.shouldRegisterWithEureka() && !config.shouldFetchRegistry()) {
logger.info("Client configured to neither register nor query for data.");
scheduler = null;
heartbeatExecutor = null;
cacheRefreshExecutor = null;
eurekaTransport = null;
instanceRegionChecker = new InstanceRegionChecker(new PropertyBasedAzToRegionMapper(config), clientConfig.getRegion());

// This is a bit of hack to allow for existing code using DiscoveryManager.getInstance()
// to work with DI'd DiscoveryClient
DiscoveryManager.getInstance().setDiscoveryClient(this);
DiscoveryManager.getInstance().setEurekaClientConfig(config);

initTimestampMs = System.currentTimeMillis();
logger.info("Discovery Client initialized at timestamp {} with initial instances count: {}",
initTimestampMs, this.getApplications().size());

return; // no need to setup up an network tasks and we are done
}

try {
// default size of 2 - 1 each for heartbeat and cacheRefresh
scheduler = Executors.newScheduledThreadPool(2,
new ThreadFactoryBuilder()
.setNameFormat("DiscoveryClient-%d")
.setDaemon(true)
.build());

heartbeatExecutor = new ThreadPoolExecutor(
1, clientConfig.getHeartbeatExecutorThreadPoolSize(), 0, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>(),
new ThreadFactoryBuilder()
.setNameFormat("DiscoveryClient-HeartbeatExecutor-%d")
.setDaemon(true)
.build()
); // use direct handoff

cacheRefreshExecutor = new ThreadPoolExecutor(
1, clientConfig.getCacheRefreshExecutorThreadPoolSize(), 0, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>(),
new ThreadFactoryBuilder()
.setNameFormat("DiscoveryClient-CacheRefreshExecutor-%d")
.setDaemon(true)
.build()
); // use direct handoff

eurekaTransport = new EurekaTransport();
scheduleServerEndpointTask(eurekaTransport, args);

AzToRegionMapper azToRegionMapper;
if (clientConfig.shouldUseDnsForFetchingServiceUrls()) {
azToRegionMapper = new DNSBasedAzToRegionMapper(clientConfig);
} else {
azToRegionMapper = new PropertyBasedAzToRegionMapper(clientConfig);
}
if (null != remoteRegionsToFetch.get()) {
azToRegionMapper.setRegionsToFetch(remoteRegionsToFetch.get().split(","));
}
instanceRegionChecker = new InstanceRegionChecker(azToRegionMapper, clientConfig.getRegion());
} catch (Throwable e) {
throw new RuntimeException("Failed to initialize DiscoveryClient!", e);
}

if (clientConfig.shouldFetchRegistry() && !fetchRegistry(false)) {
fetchRegistryFromBackup();
}

// call and execute the pre registration handler before all background tasks (inc registration) is started
if (this.preRegistrationHandler != null) {
this.preRegistrationHandler.beforeRegistration();
}

if (clientConfig.shouldRegisterWithEureka() && clientConfig.shouldEnforceRegistrationAtInit()) {
try {
if (!register() ) {
throw new IllegalStateException("Registration error at startup. Invalid server response.");
}
} catch (Throwable th) {
logger.error("Registration error at startup: {}", th.getMessage());
throw new IllegalStateException(th);
}
}

// finally, init the schedule tasks (e.g. cluster resolvers, heartbeat, instanceInfo replicator, fetch
initScheduledTasks();

try {
Monitors.registerObject(this);
} catch (Throwable e) {
logger.warn("Cannot register timers", e);
}

// This is a bit of hack to allow for existing code using DiscoveryManager.getInstance()
// to work with DI'd DiscoveryClient
DiscoveryManager.getInstance().setDiscoveryClient(this);
DiscoveryManager.getInstance().setEurekaClientConfig(config);

initTimestampMs = System.currentTimeMillis();
logger.info("Discovery Client initialized at timestamp {} with initial instances count: {}",
initTimestampMs, this.getApplications().size());
}

private void scheduleServerEndpointTask(EurekaTransport eurekaTransport,
AbstractDiscoveryClientOptionalArgs args) {


Collection<?> additionalFilters = args == null
? Collections.emptyList()
: args.additionalFilters;

EurekaJerseyClient providedJerseyClient = args == null
? null
: args.eurekaJerseyClient;

TransportClientFactories argsTransportClientFactories = null;
if (args != null && args.getTransportClientFactories() != null) {
argsTransportClientFactories = args.getTransportClientFactories();
}

// Ignore the raw types warnings since the client filter interface changed between jersey 1/2
@SuppressWarnings("rawtypes")
TransportClientFactories transportClientFactories = argsTransportClientFactories == null
? new Jersey1TransportClientFactories()
: argsTransportClientFactories;

Optional<SSLContext> sslContext = args == null
? Optional.empty()
: args.getSSLContext();
Optional<HostnameVerifier> hostnameVerifier = args == null
? Optional.empty()
: args.getHostnameVerifier();

// If the transport factory was not supplied with args, assume they are using jersey 1 for passivity
eurekaTransport.transportClientFactory = providedJerseyClient == null
? transportClientFactories.newTransportClientFactory(clientConfig, additionalFilters, applicationInfoManager.getInfo(), sslContext, hostnameVerifier)
: transportClientFactories.newTransportClientFactory(additionalFilters, providedJerseyClient);

ApplicationsResolver.ApplicationsSource applicationsSource = new ApplicationsResolver.ApplicationsSource() {
@Override
public Applications getApplications(int stalenessThreshold, TimeUnit timeUnit) {
long thresholdInMs = TimeUnit.MILLISECONDS.convert(stalenessThreshold, timeUnit);
long delay = getLastSuccessfulRegistryFetchTimePeriod();
if (delay > thresholdInMs) {
logger.info("Local registry is too stale for local lookup. Threshold:{}, actual:{}",
thresholdInMs, delay);
return null;
} else {
return localRegionApps.get();
}
}
};

eurekaTransport.bootstrapResolver = EurekaHttpClients.newBootstrapResolver(
clientConfig,
transportConfig,
eurekaTransport.transportClientFactory,
applicationInfoManager.getInfo(),
applicationsSource,
endpointRandomizer
);

if (clientConfig.shouldRegisterWithEureka()) {
EurekaHttpClientFactory newRegistrationClientFactory = null;
EurekaHttpClient newRegistrationClient = null;
try {
newRegistrationClientFactory = EurekaHttpClients.registrationClientFactory(
eurekaTransport.bootstrapResolver,
eurekaTransport.transportClientFactory,
transportConfig
);
newRegistrationClient = newRegistrationClientFactory.newClient();
} catch (Exception e) {
logger.warn("Transport initialization failure", e);
}
eurekaTransport.registrationClientFactory = newRegistrationClientFactory;
eurekaTransport.registrationClient = newRegistrationClient;
}

// new method (resolve from primary servers for read)
// Configure new transport layer (candidate for injecting in the future)
if (clientConfig.shouldFetchRegistry()) {
EurekaHttpClientFactory newQueryClientFactory = null;
EurekaHttpClient newQueryClient = null;
try {
newQueryClientFactory = EurekaHttpClients.queryClientFactory(
eurekaTransport.bootstrapResolver,
eurekaTransport.transportClientFactory,
clientConfig,
transportConfig,
applicationInfoManager.getInfo(),
applicationsSource,
endpointRandomizer
);
newQueryClient = newQueryClientFactory.newClient();
} catch (Exception e) {
logger.warn("Transport initialization failure", e);
}
eurekaTransport.queryClientFactory = newQueryClientFactory;
eurekaTransport.queryClient = newQueryClient;
}
}

@Override
public EurekaClientConfig getEurekaClientConfig() {
return clientConfig;
}

@Override
public ApplicationInfoManager getApplicationInfoManager() {
return applicationInfoManager;
}

/*
* (non-Javadoc)
* @see com.netflix.discovery.shared.LookupService#getApplication(java.lang.String)
*/
@Override
public Application getApplication(String appName) {
return getApplications().getRegisteredApplications(appName);
}

/*
* (non-Javadoc)
*
* @see com.netflix.discovery.shared.LookupService#getApplications()
*/
@Override
public Applications getApplications() {
return localRegionApps.get();
}

@Override
public Applications getApplicationsForARegion(@Nullable String region) {
if (instanceRegionChecker.isLocalRegion(region)) {
return localRegionApps.get();
} else {
return remoteRegionVsApps.get(region);
}
}

public Set<String> getAllKnownRegions() {
String localRegion = instanceRegionChecker.getLocalRegion();
if (!remoteRegionVsApps.isEmpty()) {
Set<String> regions = remoteRegionVsApps.keySet();
Set<String> toReturn = new HashSet<String>(regions);
toReturn.add(localRegion);
return toReturn;
} else {
return Collections.singleton(localRegion);
}
}

/*
* (non-Javadoc)
* @see com.netflix.discovery.shared.LookupService#getInstancesById(java.lang.String)
*/
@Override
public List<InstanceInfo> getInstancesById(String id) {
List<InstanceInfo> instancesList = new ArrayList<InstanceInfo>();
for (Application app : this.getApplications()
.getRegisteredApplications()) {
InstanceInfo instanceInfo = app.getByInstanceId(id);
if (instanceInfo != null) {
instancesList.add(instanceInfo);
}
}
return instancesList;
}

/**
* Register {@link HealthCheckCallback} with the eureka client.
*
* Once registered, the eureka client will invoke the
* {@link HealthCheckCallback} in intervals specified by
* {@link EurekaClientConfig#getInstanceInfoReplicationIntervalSeconds()}.
*
* @param callback app specific healthcheck.
*
* @deprecated Use
*/
@Deprecated
@Override
public void registerHealthCheckCallback(HealthCheckCallback callback) {
if (instanceInfo == null) {
logger.error("Cannot register a listener for instance info since it is null!");
}
if (callback != null) {
healthCheckHandlerRef.set(new HealthCheckCallbackToHandlerBridge(callback));
}
}

@Override
public void registerHealthCheck(HealthCheckHandler healthCheckHandler) {
if (instanceInfo == null) {
logger.error("Cannot register a healthcheck handler when instance info is null!");
}
if (healthCheckHandler != null) {
this.healthCheckHandlerRef.set(healthCheckHandler);
// schedule an onDemand update of the instanceInfo when a new healthcheck handler is registered
if (instanceInfoReplicator != null) {
instanceInfoReplicator.onDemandUpdate();
}
}
}

@Override
public void registerEventListener(EurekaEventListener eventListener) {
this.eventListeners.add(eventListener);
}

@Override
public boolean unregisterEventListener(EurekaEventListener eventListener) {
return this.eventListeners.remove(eventListener);
}

/**
* Gets the list of instances matching the given VIP Address.
*
* @param vipAddress
* - The VIP address to match the instances for.
* @param secure
* - true if it is a secure vip address, false otherwise
* @return - The list of {@link InstanceInfo} objects matching the criteria
*/
@Override
public List<InstanceInfo> getInstancesByVipAddress(String vipAddress, boolean secure) {
return getInstancesByVipAddress(vipAddress, secure, instanceRegionChecker.getLocalRegion());
}

/**
* Gets the list of instances matching the given VIP Address in the passed region.
*
* @param vipAddress - The VIP address to match the instances for.
* @param secure - true if it is a secure vip address, false otherwise
* @param region - region from which the instances are to be fetched. If <code>null</code> then local region is
* assumed.
*
* @return - The list of {@link InstanceInfo} objects matching the criteria, empty list if not instances found.
*/
@Override
public List<InstanceInfo> getInstancesByVipAddress(String vipAddress, boolean secure,
@Nullable String region) {
if (vipAddress == null) {
throw new IllegalArgumentException(
"Supplied VIP Address cannot be null");
}
Applications applications;
if (instanceRegionChecker.isLocalRegion(region)) {
applications = this.localRegionApps.get();
} else {
applications = remoteRegionVsApps.get(region);
if (null == applications) {
logger.debug("No applications are defined for region {}, so returning an empty instance list for vip "
+ "address {}.", region, vipAddress);
return Collections.emptyList();
}
}

if (!secure) {
return applications.getInstancesByVirtualHostName(vipAddress);
} else {
return applications.getInstancesBySecureVirtualHostName(vipAddress);

}

}

/**
* Gets the list of instances matching the given VIP Address and the given
* application name if both of them are not null. If one of them is null,
* then that criterion is completely ignored for matching instances.
*
* @param vipAddress
* - The VIP address to match the instances for.
* @param appName
* - The applicationName to match the instances for.
* @param secure
* - true if it is a secure vip address, false otherwise.
* @return - The list of {@link InstanceInfo} objects matching the criteria.
*/
@Override
public List<InstanceInfo> getInstancesByVipAddressAndAppName(
String vipAddress, String appName, boolean secure) {

List<InstanceInfo> result = new ArrayList<InstanceInfo>();
if (vipAddress == null && appName == null) {
throw new IllegalArgumentException(
"Supplied VIP Address and application name cannot both be null");
} else if (vipAddress != null && appName == null) {
return getInstancesByVipAddress(vipAddress, secure);
} else if (vipAddress == null && appName != null) {
Application application = getApplication(appName);
if (application != null) {
result = application.getInstances();
}
return result;
}

String instanceVipAddress;
for (Application app : getApplications().getRegisteredApplications()) {
for (InstanceInfo instance : app.getInstances()) {
if (secure) {
instanceVipAddress = instance.getSecureVipAddress();
} else {
instanceVipAddress = instance.getVIPAddress();
}
if (instanceVipAddress == null) {
continue;
}
String[] instanceVipAddresses = instanceVipAddress
.split(COMMA_STRING);

// If the VIP Address is delimited by a comma, then consider to
// be a list of VIP Addresses.
// Try to match at least one in the list, if it matches then
// return the instance info for the same
for (String vipAddressFromList : instanceVipAddresses) {
if (vipAddress.equalsIgnoreCase(vipAddressFromList.trim())
&& appName.equalsIgnoreCase(instance.getAppName())) {
result.add(instance);
break;
}
}
}
}
return result;
}

/*
* (non-Javadoc)
*
* @see
* com.netflix.discovery.shared.LookupService#getNextServerFromEureka(java
* .lang.String, boolean)
*/
@Override
public InstanceInfo getNextServerFromEureka(String virtualHostname, boolean secure) {
List<InstanceInfo> instanceInfoList = this.getInstancesByVipAddress(
virtualHostname, secure);
if (instanceInfoList == null || instanceInfoList.isEmpty()) {
throw new RuntimeException("No matches for the virtual host name :"
+ virtualHostname);
}
Applications apps = this.localRegionApps.get();
int index = (int) (apps.getNextIndex(virtualHostname,
secure).incrementAndGet() % instanceInfoList.size());
return instanceInfoList.get(index);
}

/**
* Get all applications registered with a specific eureka service.
*
* @param serviceUrl
* - The string representation of the service url.
* @return - The registry information containing all applications.
*/
@Override
public Applications getApplications(String serviceUrl) {
try {
EurekaHttpResponse<Applications> response = clientConfig.getRegistryRefreshSingleVipAddress() == null
? eurekaTransport.queryClient.getApplications()
: eurekaTransport.queryClient.getVip(clientConfig.getRegistryRefreshSingleVipAddress());
if (response.getStatusCode() == Status.OK.getStatusCode()) {
logger.debug(PREFIX + "{} - refresh status: {}", appPathIdentifier, response.getStatusCode());
return response.getEntity();
}
logger.error(PREFIX + "{} - was unable to refresh its cache! status = {}", appPathIdentifier, response.getStatusCode());
} catch (Throwable th) {
logger.error(PREFIX + "{} - was unable to refresh its cache! status = {}", appPathIdentifier, th.getMessage(), th);
}
return null;
}

/**
* Register with the eureka service by making the appropriate REST call.
*/
boolean register() throws Throwable {
logger.info(PREFIX + "{}: registering service...", appPathIdentifier);
EurekaHttpResponse<Void> httpResponse;
try {
httpResponse = eurekaTransport.registrationClient.register(instanceInfo);
} catch (Exception e) {
logger.warn(PREFIX + "{} - registration failed {}", appPathIdentifier, e.getMessage(), e);
throw e;
}
if (logger.isInfoEnabled()) {
logger.info(PREFIX + "{} - registration status: {}", appPathIdentifier, httpResponse.getStatusCode());
}
return httpResponse.getStatusCode() == Status.NO_CONTENT.getStatusCode();
}

/**
* Renew with the eureka service by making the appropriate REST call
*/
boolean renew() {
EurekaHttpResponse<InstanceInfo> httpResponse;
try {
httpResponse = eurekaTransport.registrationClient.sendHeartBeat(instanceInfo.getAppName(), instanceInfo.getId(), instanceInfo, null);
logger.debug(PREFIX + "{} - Heartbeat status: {}", appPathIdentifier, httpResponse.getStatusCode());
if (httpResponse.getStatusCode() == Status.NOT_FOUND.getStatusCode()) {
REREGISTER_COUNTER.increment();
logger.info(PREFIX + "{} - Re-registering apps/{}", appPathIdentifier, instanceInfo.getAppName());
long timestamp = instanceInfo.setIsDirtyWithTime();
boolean success = register();
if (success) {
instanceInfo.unsetIsDirty(timestamp);
}
return success;
}
return httpResponse.getStatusCode() == Status.OK.getStatusCode();
} catch (Throwable e) {
logger.error(PREFIX + "{} - was unable to send heartbeat!", appPathIdentifier, e);
return false;
}
}

/**
* @deprecated see replacement in {@link com.netflix.discovery.endpoint.EndpointUtils}
*
* Get the list of all eureka service urls from properties file for the eureka client to talk to.
*
* @param instanceZone The zone in which the client resides
* @param preferSameZone true if we have to prefer the same zone as the client, false otherwise
* @return The list of all eureka service urls for the eureka client to talk to
*/
@Deprecated
@Override
public List<String> getServiceUrlsFromConfig(String instanceZone, boolean preferSameZone) {
return EndpointUtils.getServiceUrlsFromConfig(clientConfig, instanceZone, preferSameZone);
}

/**
* Shuts down Eureka Client. Also sends a deregistration request to the
* eureka server.
*/
@PreDestroy
@Override
public synchronized void shutdown() {
if (isShutdown.compareAndSet(false, true)) {
logger.info("Shutting down DiscoveryClient ...");

if (statusChangeListener != null && applicationInfoManager != null) {
applicationInfoManager.unregisterStatusChangeListener(statusChangeListener.getId());
}

cancelScheduledTasks();

// If APPINFO was registered
if (applicationInfoManager != null
&& clientConfig.shouldRegisterWithEureka()
&& clientConfig.shouldUnregisterOnShutdown()) {
applicationInfoManager.setInstanceStatus(InstanceStatus.DOWN);
unregister();
}

if (eurekaTransport != null) {
eurekaTransport.shutdown();
}

heartbeatStalenessMonitor.shutdown();
registryStalenessMonitor.shutdown();

logger.info("Completed shut down of DiscoveryClient");
}
}

/**
* unregister w/ the eureka service.
*/
void unregister() {
// It can be null if shouldRegisterWithEureka == false
if(eurekaTransport != null && eurekaTransport.registrationClient != null) {
try {
logger.info("Unregistering ...");
EurekaHttpResponse<Void> httpResponse = eurekaTransport.registrationClient.cancel(instanceInfo.getAppName(), instanceInfo.getId());
logger.info(PREFIX + "{} - deregister status: {}", appPathIdentifier, httpResponse.getStatusCode());
} catch (Exception e) {
logger.error(PREFIX + "{} - de-registration failed{}", appPathIdentifier, e.getMessage(), e);
}
}
}

/**
* Fetches the registry information.
*
* <p>
* This method tries to get only deltas after the first fetch unless there
* is an issue in reconciling eureka server and client registry information.
* </p>
*
* @param forceFullRegistryFetch Forces a full registry fetch.
*
* @return true if the registry was fetched
*/
private boolean fetchRegistry(boolean forceFullRegistryFetch) {
Stopwatch tracer = FETCH_REGISTRY_TIMER.start();

try {
// If the delta is disabled or if it is the first time, get all
// applications
Applications applications = getApplications();

if (clientConfig.shouldDisableDelta()
|| (!Strings.isNullOrEmpty(clientConfig.getRegistryRefreshSingleVipAddress()))
|| forceFullRegistryFetch
|| (applications == null)
|| (applications.getRegisteredApplications().size() == 0)
|| (applications.getVersion() == -1)) //Client application does not have latest library supporting delta
{
logger.info("Disable delta property : {}", clientConfig.shouldDisableDelta());
logger.info("Single vip registry refresh property : {}", clientConfig.getRegistryRefreshSingleVipAddress());
logger.info("Force full registry fetch : {}", forceFullRegistryFetch);
logger.info("Application is null : {}", (applications == null));
logger.info("Registered Applications size is zero : {}",
(applications.getRegisteredApplications().size() == 0));
logger.info("Application version is -1: {}", (applications.getVersion() == -1));
getAndStoreFullRegistry();
} else {
getAndUpdateDelta(applications);
}
applications.setAppsHashCode(applications.getReconcileHashCode());
logTotalInstances();
} catch (Throwable e) {
logger.error(PREFIX + "{} - was unable to refresh its cache! status = {}", appPathIdentifier, e.getMessage(), e);
return false;
} finally {
if (tracer != null) {
tracer.stop();
}
}

// Notify about cache refresh before updating the instance remote status
onCacheRefreshed();

// Update remote status based on refreshed data held in the cache
updateInstanceRemoteStatus();

// registry was fetched successfully, so return true
return true;
}

private synchronized void updateInstanceRemoteStatus() {
// Determine this instance's status for this app and set to UNKNOWN if not found
InstanceInfo.InstanceStatus currentRemoteInstanceStatus = null;
if (instanceInfo.getAppName() != null) {
Application app = getApplication(instanceInfo.getAppName());
if (app != null) {
InstanceInfo remoteInstanceInfo = app.getByInstanceId(instanceInfo.getId());
if (remoteInstanceInfo != null) {
currentRemoteInstanceStatus = remoteInstanceInfo.getStatus();
}
}
}
if (currentRemoteInstanceStatus == null) {
currentRemoteInstanceStatus = InstanceInfo.InstanceStatus.UNKNOWN;
}

// Notify if status changed
if (lastRemoteInstanceStatus != currentRemoteInstanceStatus) {
onRemoteStatusChanged(lastRemoteInstanceStatus, currentRemoteInstanceStatus);
lastRemoteInstanceStatus = currentRemoteInstanceStatus;
}
}

/**
* @return Return he current instance status as seen on the Eureka server.
*/
@Override
public InstanceInfo.InstanceStatus getInstanceRemoteStatus() {
return lastRemoteInstanceStatus;
}

private String getReconcileHashCode(Applications applications) {
TreeMap<String, AtomicInteger> instanceCountMap = new TreeMap<String, AtomicInteger>();
if (isFetchingRemoteRegionRegistries()) {
for (Applications remoteApp : remoteRegionVsApps.values()) {
remoteApp.populateInstanceCountMap(instanceCountMap);
}
}
applications.populateInstanceCountMap(instanceCountMap);
return Applications.getReconcileHashCode(instanceCountMap);
}

/**
* Gets the full registry information from the eureka server and stores it locally.
* When applying the full registry, the following flow is observed:
*
* if (update generation have not advanced (due to another thread))
* atomically set the registry to the new registry
* fi
*
* @return the full registry information.
* @throws Throwable
* on error.
*/
private void getAndStoreFullRegistry() throws Throwable {
long currentUpdateGeneration = fetchRegistryGeneration.get();

logger.info("Getting all instance registry info from the eureka server");

Applications apps = null;
EurekaHttpResponse<Applications> httpResponse = clientConfig.getRegistryRefreshSingleVipAddress() == null
? eurekaTransport.queryClient.getApplications(remoteRegionsRef.get())
: eurekaTransport.queryClient.getVip(clientConfig.getRegistryRefreshSingleVipAddress(), remoteRegionsRef.get());
if (httpResponse.getStatusCode() == Status.OK.getStatusCode()) {
apps = httpResponse.getEntity();
}
logger.info("The response status is {}", httpResponse.getStatusCode());

if (apps == null) {
logger.error("The application is null for some reason. Not storing this information");
} else if (fetchRegistryGeneration.compareAndSet(currentUpdateGeneration, currentUpdateGeneration + 1)) {
localRegionApps.set(this.filterAndShuffle(apps));
logger.debug("Got full registry with apps hashcode {}", apps.getAppsHashCode());
} else {
logger.warn("Not updating applications as another thread is updating it already");
}
}

/**
* Get the delta registry information from the eureka server and update it locally.
* When applying the delta, the following flow is observed:
*
* if (update generation have not advanced (due to another thread))
* atomically try to: update application with the delta and get reconcileHashCode
* abort entire processing otherwise
* do reconciliation if reconcileHashCode clash
* fi
*
* @return the client response
* @throws Throwable on error
*/
private void getAndUpdateDelta(Applications applications) throws Throwable {
long currentUpdateGeneration = fetchRegistryGeneration.get();

Applications delta = null;
EurekaHttpResponse<Applications> httpResponse = eurekaTransport.queryClient.getDelta(remoteRegionsRef.get());
if (httpResponse.getStatusCode() == Status.OK.getStatusCode()) {
delta = httpResponse.getEntity();
}

if (delta == null) {
logger.warn("The server does not allow the delta revision to be applied because it is not safe. "
+ "Hence got the full registry.");
getAndStoreFullRegistry();
} else if (fetchRegistryGeneration.compareAndSet(currentUpdateGeneration, currentUpdateGeneration + 1)) {
logger.debug("Got delta update with apps hashcode {}", delta.getAppsHashCode());
String reconcileHashCode = "";
if (fetchRegistryUpdateLock.tryLock()) {
try {
updateDelta(delta);
reconcileHashCode = getReconcileHashCode(applications);
} finally {
fetchRegistryUpdateLock.unlock();
}
} else {
logger.warn("Cannot acquire update lock, aborting getAndUpdateDelta");
}
// There is a diff in number of instances for some reason
if (!reconcileHashCode.equals(delta.getAppsHashCode()) || clientConfig.shouldLogDeltaDiff()) {
reconcileAndLogDifference(delta, reconcileHashCode); // this makes a remoteCall
}
} else {
logger.warn("Not updating application delta as another thread is updating it already");
logger.debug("Ignoring delta update with apps hashcode {}, as another thread is updating it already", delta.getAppsHashCode());
}
}

/**
* Logs the total number of non-filtered instances stored locally.
*/
private void logTotalInstances() {
if (logger.isDebugEnabled()) {
int totInstances = 0;
for (Application application : getApplications().getRegisteredApplications()) {
totInstances += application.getInstancesAsIsFromEureka().size();
}
logger.debug("The total number of all instances in the client now is {}", totInstances);
}
}

/**
* Reconcile the eureka server and client registry information and logs the differences if any.
* When reconciling, the following flow is observed:
*
* make a remote call to the server for the full registry
* calculate and log differences
* if (update generation have not advanced (due to another thread))
* atomically set the registry to the new registry
* fi
*
* @param delta
* the last delta registry information received from the eureka
* server.
* @param reconcileHashCode
* the hashcode generated by the server for reconciliation.
* @return ClientResponse the HTTP response object.
* @throws Throwable
* on any error.
*/
private void reconcileAndLogDifference(Applications delta, String reconcileHashCode) throws Throwable {
logger.debug("The Reconcile hashcodes do not match, client : {}, server : {}. Getting the full registry",
reconcileHashCode, delta.getAppsHashCode());

RECONCILE_HASH_CODES_MISMATCH.increment();

long currentUpdateGeneration = fetchRegistryGeneration.get();

EurekaHttpResponse<Applications> httpResponse = clientConfig.getRegistryRefreshSingleVipAddress() == null
? eurekaTransport.queryClient.getApplications(remoteRegionsRef.get())
: eurekaTransport.queryClient.getVip(clientConfig.getRegistryRefreshSingleVipAddress(), remoteRegionsRef.get());
Applications serverApps = httpResponse.getEntity();

if (serverApps == null) {
logger.warn("Cannot fetch full registry from the server; reconciliation failure");
return;
}

if (fetchRegistryGeneration.compareAndSet(currentUpdateGeneration, currentUpdateGeneration + 1)) {
localRegionApps.set(this.filterAndShuffle(serverApps));
getApplications().setVersion(delta.getVersion());
logger.debug(
"The Reconcile hashcodes after complete sync up, client : {}, server : {}.",
getApplications().getReconcileHashCode(),
delta.getAppsHashCode());
} else {
logger.warn("Not setting the applications map as another thread has advanced the update generation");
}
}

/**
* Updates the delta information fetches from the eureka server into the
* local cache.
*
* @param delta
* the delta information received from eureka server in the last
* poll cycle.
*/
private void updateDelta(Applications delta) {
int deltaCount = 0;
for (Application app : delta.getRegisteredApplications()) {
for (InstanceInfo instance : app.getInstances()) {
Applications applications = getApplications();
String instanceRegion = instanceRegionChecker.getInstanceRegion(instance);
if (!instanceRegionChecker.isLocalRegion(instanceRegion)) {
Applications remoteApps = remoteRegionVsApps.get(instanceRegion);
if (null == remoteApps) {
remoteApps = new Applications();
remoteRegionVsApps.put(instanceRegion, remoteApps);
}
applications = remoteApps;
}

++deltaCount;
if (ActionType.ADDED.equals(instance.getActionType())) {
Application existingApp = applications.getRegisteredApplications(instance.getAppName());
if (existingApp == null) {
applications.addApplication(app);
}
logger.debug("Added instance {} to the existing apps in region {}", instance.getId(), instanceRegion);
applications.getRegisteredApplications(instance.getAppName()).addInstance(instance);
} else if (ActionType.MODIFIED.equals(instance.getActionType())) {
Application existingApp = applications.getRegisteredApplications(instance.getAppName());
if (existingApp == null) {
applications.addApplication(app);
}
logger.debug("Modified instance {} to the existing apps ", instance.getId());

applications.getRegisteredApplications(instance.getAppName()).addInstance(instance);

} else if (ActionType.DELETED.equals(instance.getActionType())) {
Application existingApp = applications.getRegisteredApplications(instance.getAppName());
if (existingApp != null) {
logger.debug("Deleted instance {} to the existing apps ", instance.getId());
existingApp.removeInstance(instance);
/*
* We find all instance list from application(The status of instance status is not only the status is UP but also other status)
* if instance list is empty, we remove the application.
*/
if (existingApp.getInstancesAsIsFromEureka().isEmpty()) {
applications.removeApplication(existingApp);
}
}
}
}
}
logger.debug("The total number of instances fetched by the delta processor : {}", deltaCount);

getApplications().setVersion(delta.getVersion());
getApplications().shuffleInstances(clientConfig.shouldFilterOnlyUpInstances());

for (Applications applications : remoteRegionVsApps.values()) {
applications.setVersion(delta.getVersion());
applications.shuffleInstances(clientConfig.shouldFilterOnlyUpInstances());
}
}

/**
* Initializes all scheduled tasks.
*/
private void initScheduledTasks() {
if (clientConfig.shouldFetchRegistry()) {
// registry cache refresh timer
int registryFetchIntervalSeconds = clientConfig.getRegistryFetchIntervalSeconds();
int expBackOffBound = clientConfig.getCacheRefreshExecutorExponentialBackOffBound();
scheduler.schedule(
new TimedSupervisorTask(
"cacheRefresh",
scheduler,
cacheRefreshExecutor,
registryFetchIntervalSeconds,
TimeUnit.SECONDS,
expBackOffBound,
new CacheRefreshThread()
),
registryFetchIntervalSeconds, TimeUnit.SECONDS);
}

if (clientConfig.shouldRegisterWithEureka()) {
int renewalIntervalInSecs = instanceInfo.getLeaseInfo().getRenewalIntervalInSecs();
int expBackOffBound = clientConfig.getHeartbeatExecutorExponentialBackOffBound();
logger.info("Starting heartbeat executor: " + "renew interval is: {}", renewalIntervalInSecs);

// Heartbeat timer
scheduler.schedule(
new TimedSupervisorTask(
"heartbeat",
scheduler,
heartbeatExecutor,
renewalIntervalInSecs,
TimeUnit.SECONDS,
expBackOffBound,
new HeartbeatThread()
),
renewalIntervalInSecs, TimeUnit.SECONDS);

// InstanceInfo replicator
instanceInfoReplicator = new InstanceInfoReplicator(
this,
instanceInfo,
clientConfig.getInstanceInfoReplicationIntervalSeconds(),
2); // burstSize

statusChangeListener = new ApplicationInfoManager.StatusChangeListener() {
@Override
public String getId() {
return "statusChangeListener";
}

@Override
public void notify(StatusChangeEvent statusChangeEvent) {
if (InstanceStatus.DOWN == statusChangeEvent.getStatus() ||
InstanceStatus.DOWN == statusChangeEvent.getPreviousStatus()) {
// log at warn level if DOWN was involved
logger.warn("Saw local status change event {}", statusChangeEvent);
} else {
logger.info("Saw local status change event {}", statusChangeEvent);
}
instanceInfoReplicator.onDemandUpdate();
}
};

if (clientConfig.shouldOnDemandUpdateStatusChange()) {
applicationInfoManager.registerStatusChangeListener(statusChangeListener);
}

instanceInfoReplicator.start(clientConfig.getInitialInstanceInfoReplicationIntervalSeconds());
} else {
logger.info("Not registering with Eureka server per configuration");
}
}

private void cancelScheduledTasks() {
if (instanceInfoReplicator != null) {
instanceInfoReplicator.stop();
}
if (heartbeatExecutor != null) {
heartbeatExecutor.shutdownNow();
}
if (cacheRefreshExecutor != null) {
cacheRefreshExecutor.shutdownNow();
}
if (scheduler != null) {
scheduler.shutdownNow();
}
}

/**
* @deprecated see replacement in {@link com.netflix.discovery.endpoint.EndpointUtils}
*
* Get the list of all eureka service urls from DNS for the eureka client to
* talk to. The client picks up the service url from its zone and then fails over to
* other zones randomly. If there are multiple servers in the same zone, the client once
* again picks one randomly. This way the traffic will be distributed in the case of failures.
*
* @param instanceZone The zone in which the client resides.
* @param preferSameZone true if we have to prefer the same zone as the client, false otherwise.
* @return The list of all eureka service urls for the eureka client to talk to.
*/
@Deprecated
@Override
public List<String> getServiceUrlsFromDNS(String instanceZone, boolean preferSameZone) {
return EndpointUtils.getServiceUrlsFromDNS(clientConfig, instanceZone, preferSameZone, urlRandomizer);
}

/**
* @deprecated see replacement in {@link com.netflix.discovery.endpoint.EndpointUtils}
*/
@Deprecated
@Override
public List<String> getDiscoveryServiceUrls(String zone) {
return EndpointUtils.getDiscoveryServiceUrls(clientConfig, zone, urlRandomizer);
}

/**
* @deprecated see replacement in {@link com.netflix.discovery.endpoint.EndpointUtils}
*
* Get the list of EC2 URLs given the zone name.
*
* @param dnsName The dns name of the zone-specific CNAME
* @param type CNAME or EIP that needs to be retrieved
* @return The list of EC2 URLs associated with the dns name
*/
@Deprecated
public static Set<String> getEC2DiscoveryUrlsFromZone(String dnsName,
EndpointUtils.DiscoveryUrlType type) {
return EndpointUtils.getEC2DiscoveryUrlsFromZone(dnsName, type);
}

/**
* Refresh the current local instanceInfo. Note that after a valid refresh where changes are observed, the
* isDirty flag on the instanceInfo is set to true
*/
void refreshInstanceInfo() {
applicationInfoManager.refreshDataCenterInfoIfRequired();
applicationInfoManager.refreshLeaseInfoIfRequired();

InstanceStatus status;
try {
status = getHealthCheckHandler().getStatus(instanceInfo.getStatus());
} catch (Exception e) {
logger.warn("Exception from healthcheckHandler.getStatus, setting status to DOWN", e);
status = InstanceStatus.DOWN;
}

if (null != status) {
applicationInfoManager.setInstanceStatus(status);
}
}

/**
* The heartbeat task that renews the lease in the given intervals.
*/
private class HeartbeatThread implements Runnable {

public void run() {
if (renew()) {
lastSuccessfulHeartbeatTimestamp = System.currentTimeMillis();
}
}
}

@VisibleForTesting
InstanceInfoReplicator getInstanceInfoReplicator() {
return instanceInfoReplicator;
}

@VisibleForTesting
InstanceInfo getInstanceInfo() {
return instanceInfo;
}

@Override
public HealthCheckHandler getHealthCheckHandler() {
HealthCheckHandler healthCheckHandler = this.healthCheckHandlerRef.get();
if (healthCheckHandler == null) {
if (null != healthCheckHandlerProvider) {
healthCheckHandler = healthCheckHandlerProvider.get();
} else if (null != healthCheckCallbackProvider) {
healthCheckHandler = new HealthCheckCallbackToHandlerBridge(healthCheckCallbackProvider.get());
}

if (null == healthCheckHandler) {
healthCheckHandler = new HealthCheckCallbackToHandlerBridge(null);
}
this.healthCheckHandlerRef.compareAndSet(null, healthCheckHandler);
}

return this.healthCheckHandlerRef.get();
}

/**
* The task that fetches the registry information at specified intervals.
*
*/
class CacheRefreshThread implements Runnable {
public void run() {
refreshRegistry();
}
}

@VisibleForTesting
void refreshRegistry() {
try {
boolean isFetchingRemoteRegionRegistries = isFetchingRemoteRegionRegistries();

boolean remoteRegionsModified = false;
// This makes sure that a dynamic change to remote regions to fetch is honored.
String latestRemoteRegions = clientConfig.fetchRegistryForRemoteRegions();
if (null != latestRemoteRegions) {
String currentRemoteRegions = remoteRegionsToFetch.get();
if (!latestRemoteRegions.equals(currentRemoteRegions)) {
// Both remoteRegionsToFetch and AzToRegionMapper.regionsToFetch need to be in sync
synchronized (instanceRegionChecker.getAzToRegionMapper()) {
if (remoteRegionsToFetch.compareAndSet(currentRemoteRegions, latestRemoteRegions)) {
String[] remoteRegions = latestRemoteRegions.split(",");
remoteRegionsRef.set(remoteRegions);
instanceRegionChecker.getAzToRegionMapper().setRegionsToFetch(remoteRegions);
remoteRegionsModified = true;
} else {
logger.info("Remote regions to fetch modified concurrently," +
" ignoring change from {} to {}", currentRemoteRegions, latestRemoteRegions);
}
}
} else {
// Just refresh mapping to reflect any DNS/Property change
instanceRegionChecker.getAzToRegionMapper().refreshMapping();
}
}

boolean success = fetchRegistry(remoteRegionsModified);
if (success) {
registrySize = localRegionApps.get().size();
lastSuccessfulRegistryFetchTimestamp = System.currentTimeMillis();
}

if (logger.isDebugEnabled()) {
StringBuilder allAppsHashCodes = new StringBuilder();
allAppsHashCodes.append("Local region apps hashcode: ");
allAppsHashCodes.append(localRegionApps.get().getAppsHashCode());
allAppsHashCodes.append(", is fetching remote regions? ");
allAppsHashCodes.append(isFetchingRemoteRegionRegistries);
for (Map.Entry<String, Applications> entry : remoteRegionVsApps.entrySet()) {
allAppsHashCodes.append(", Remote region: ");
allAppsHashCodes.append(entry.getKey());
allAppsHashCodes.append(" , apps hashcode: ");
allAppsHashCodes.append(entry.getValue().getAppsHashCode());
}
logger.debug("Completed cache refresh task for discovery. All Apps hash code is {} ",
allAppsHashCodes);
}
} catch (Throwable e) {
logger.error("Cannot fetch registry from server", e);
}
}

/**
* Fetch the registry information from back up registry if all eureka server
* urls are unreachable.
*/
private void fetchRegistryFromBackup() {
try {
@SuppressWarnings("deprecation")
BackupRegistry backupRegistryInstance = newBackupRegistryInstance();
if (null == backupRegistryInstance) { // backward compatibility with the old protected method, in case it is being used.
backupRegistryInstance = backupRegistryProvider.get();
}

if (null != backupRegistryInstance) {
Applications apps = null;
if (isFetchingRemoteRegionRegistries()) {
String remoteRegionsStr = remoteRegionsToFetch.get();
if (null != remoteRegionsStr) {
apps = backupRegistryInstance.fetchRegistry(remoteRegionsStr.split(","));
}
} else {
apps = backupRegistryInstance.fetchRegistry();
}
if (apps != null) {
final Applications applications = this.filterAndShuffle(apps);
applications.setAppsHashCode(applications.getReconcileHashCode());
localRegionApps.set(applications);
logTotalInstances();
logger.info("Fetched registry successfully from the backup");
}
} else {
logger.warn("No backup registry instance defined & unable to find any discovery servers.");
}
} catch (Throwable e) {
logger.warn("Cannot fetch applications from apps although backup registry was specified", e);
}
}

/**
* @deprecated Use injection to provide {@link BackupRegistry} implementation.
*/
@Deprecated
@Nullable
protected BackupRegistry newBackupRegistryInstance()
throws ClassNotFoundException, IllegalAccessException, InstantiationException {
return null;
}

/**
* Gets the <em>applications</em> after filtering the applications for
* instances with only UP states and shuffling them.
*
* <p>
* The filtering depends on the option specified by the configuration
* {@link EurekaClientConfig#shouldFilterOnlyUpInstances()}. Shuffling helps
* in randomizing the applications list there by avoiding the same instances
* receiving traffic during start ups.
* </p>
*
* @param apps
* The applications that needs to be filtered and shuffled.
* @return The applications after the filter and the shuffle.
*/
private Applications filterAndShuffle(Applications apps) {
if (apps != null) {
if (isFetchingRemoteRegionRegistries()) {
Map<String, Applications> remoteRegionVsApps = new ConcurrentHashMap<String, Applications>();
apps.shuffleAndIndexInstances(remoteRegionVsApps, clientConfig, instanceRegionChecker);
for (Applications applications : remoteRegionVsApps.values()) {
applications.shuffleInstances(clientConfig.shouldFilterOnlyUpInstances());
}
this.remoteRegionVsApps = remoteRegionVsApps;
} else {
apps.shuffleInstances(clientConfig.shouldFilterOnlyUpInstances());
}
}
return apps;
}

private boolean isFetchingRemoteRegionRegistries() {
return null != remoteRegionsToFetch.get();
}

/**
* Invoked when the remote status of this client has changed.
* Subclasses may override this method to implement custom behavior if needed.
*
* @param oldStatus the previous remote {@link InstanceStatus}
* @param newStatus the new remote {@link InstanceStatus}
*/
protected void onRemoteStatusChanged(InstanceInfo.InstanceStatus oldStatus, InstanceInfo.InstanceStatus newStatus) {
fireEvent(new StatusChangeEvent(oldStatus, newStatus));
}


/**
* Invoked every time the local registry cache is refreshed (whether changes have
* been detected or not).
*
* Subclasses may override this method to implement custom behavior if needed.
*/
protected void onCacheRefreshed() {
fireEvent(new CacheRefreshedEvent());
}

/**
* Send the given event on the EventBus if one is available
*
* @param event the event to send on the eventBus
*/
protected void fireEvent(final EurekaEvent event) {
for (EurekaEventListener listener : eventListeners) {
try {
listener.onEvent(event);
} catch (Exception e) {
logger.info("Event {} throw an exception for listener {}", event, listener, e.getMessage());
}
}
}


/**
* @deprecated see {@link com.netflix.appinfo.InstanceInfo#getZone(String[], com.netflix.appinfo.InstanceInfo)}
*
* Get the zone that a particular instance is in.
*
* @param myInfo
* - The InstanceInfo object of the instance.
* @return - The zone in which the particular instance belongs to.
*/
@Deprecated
public static String getZone(InstanceInfo myInfo) {
String[] availZones = staticClientConfig.getAvailabilityZones(staticClientConfig.getRegion());
return InstanceInfo.getZone(availZones, myInfo);
}

/**
* @deprecated see replacement in {@link com.netflix.discovery.endpoint.EndpointUtils}
*
* Get the region that this particular instance is in.
*
* @return - The region in which the particular instance belongs to.
*/
@Deprecated
public static String getRegion() {
String region = staticClientConfig.getRegion();
if (region == null) {
region = "default";
}
region = region.trim().toLowerCase();
return region;
}

/**
* @deprecated use {@link #getServiceUrlsFromConfig(String, boolean)} instead.
*/
@Deprecated
public static List<String> getEurekaServiceUrlsFromConfig(String instanceZone, boolean preferSameZone) {
return EndpointUtils.getServiceUrlsFromConfig(staticClientConfig, instanceZone, preferSameZone);
}

public long getLastSuccessfulHeartbeatTimePeriod() {
return lastSuccessfulHeartbeatTimestamp < 0
? lastSuccessfulHeartbeatTimestamp
: System.currentTimeMillis() - lastSuccessfulHeartbeatTimestamp;
}

public long getLastSuccessfulRegistryFetchTimePeriod() {
return lastSuccessfulRegistryFetchTimestamp < 0
? lastSuccessfulRegistryFetchTimestamp
: System.currentTimeMillis() - lastSuccessfulRegistryFetchTimestamp;
}

@com.netflix.servo.annotations.Monitor(name = METRIC_REGISTRATION_PREFIX + "lastSuccessfulHeartbeatTimePeriod",
description = "How much time has passed from last successful heartbeat", type = DataSourceType.GAUGE)
private long getLastSuccessfulHeartbeatTimePeriodInternal() {
final long delay = (!clientConfig.shouldRegisterWithEureka() || isShutdown.get())
? 0
: getLastSuccessfulHeartbeatTimePeriod();

heartbeatStalenessMonitor.update(computeStalenessMonitorDelay(delay));
return delay;
}

// for metrics only
@com.netflix.servo.annotations.Monitor(name = METRIC_REGISTRY_PREFIX + "lastSuccessfulRegistryFetchTimePeriod",
description = "How much time has passed from last successful local registry update", type = DataSourceType.GAUGE)
private long getLastSuccessfulRegistryFetchTimePeriodInternal() {
final long delay = (!clientConfig.shouldFetchRegistry() || isShutdown.get())
? 0
: getLastSuccessfulRegistryFetchTimePeriod();

registryStalenessMonitor.update(computeStalenessMonitorDelay(delay));
return delay;
}

@com.netflix.servo.annotations.Monitor(name = METRIC_REGISTRY_PREFIX + "localRegistrySize",
description = "Count of instances in the local registry", type = DataSourceType.GAUGE)
public int localRegistrySize() {
return registrySize;
}


private long computeStalenessMonitorDelay(long delay) {
if (delay < 0) {
return System.currentTimeMillis() - initTimestampMs;
} else {
return delay;
}
}

}