org.kiwiproject.registry.eureka.server.EurekaRegistryService Maven / Gradle / Ivy
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package org.kiwiproject.registry.eureka.server;
import static com.google.common.base.Preconditions.checkState;
import static java.time.ZoneOffset.UTC;
import static java.util.Objects.isNull;
import static java.util.Objects.nonNull;
import static javax.ws.rs.core.Response.Status.NO_CONTENT;
import static javax.ws.rs.core.Response.Status.OK;
import static org.kiwiproject.base.KiwiStrings.f;
import static org.kiwiproject.base.KiwiStrings.format;
import static org.kiwiproject.collect.KiwiLists.isNotNullOrEmpty;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.extern.slf4j.Slf4j;
import org.kiwiproject.base.KiwiEnvironment;
import org.kiwiproject.base.Optionals;
import org.kiwiproject.registry.config.ServiceInfo;
import org.kiwiproject.registry.eureka.common.EurekaInstance;
import org.kiwiproject.registry.eureka.common.EurekaRestClient;
import org.kiwiproject.registry.eureka.common.EurekaUrlProvider;
import org.kiwiproject.registry.eureka.config.EurekaRegistrationConfig;
import org.kiwiproject.registry.exception.RegistrationException;
import org.kiwiproject.registry.model.NativeRegistryData;
import org.kiwiproject.registry.model.ServiceInstance;
import org.kiwiproject.registry.model.ServiceInstance.Status;
import org.kiwiproject.registry.server.RegistryService;
import org.kiwiproject.retry.SimpleRetryer;
import javax.ws.rs.core.GenericType;
import javax.ws.rs.core.Response;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAccessor;
import java.util.Date;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Function;
import java.util.function.Supplier;
@Slf4j
public class EurekaRegistryService implements RegistryService {
/**
* @implNote Need to specify the override zone via {@link DateTimeFormatter#withZone(ZoneId)}, otherwise when trying
* to format a {@link Date} the formatter will fail with the error:
* {@code "java.time.temporal.UnsupportedTemporalTypeException: Unsupported field: YearOfEra"}
*
* This is because {@link DateTimeFormatter#format(TemporalAccessor)} accepts a {@link java.time.temporal.TemporalAccessor}
* of which {@link Date} is definitely not an instance. You therefore need to convert the Date to an Instant and
* then call format. However, a time zone is required to format an Instant, thus this is an easy way to do it
* globally for any Date instance that is converted to an Instant.
*/
@VisibleForTesting
static final DateTimeFormatter APP_TIMESTAMP_FORMATTER = DateTimeFormatter.ofPattern("yyyyMMddHHmmss.SSS").withZone(UTC);
/**
* Funny story ... this class doesn't actually exist. It's for "backwards compatibility".
*
* See com.netflix.discovery.converters.jackson.DataCenterTypeInfoResolver for details.
* (NOTE: javadoc annotation not used to avoid unnecessary errors.)
*/
public static final String DEFAULT_DATA_CENTER_INFO_CLASS = "com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo";
public static final String DEFAULT_DATA_CENTER_NAME = "MyOwn";
/**
* Key for lease info representing lease duration in seconds.
*/
public static final String LEASE_DURATION_IN_SECONDS = "durationInSecs";
/**
* Key for lease info representing renewal interval in seconds.
*/
public static final String LEASE_RENEWAL_INTERVAL_IN_SECONDS = "renewalIntervalInSecs";
private static final String SERVICE_UP_TIMESTAMP_FIELD = "serviceUpTimestamp";
/**
* Maximum number of attempts we will make to await confirmation that we're registered with Eureka.
*/
public static final int MAX_AWAIT_REGISTRATION_CONFIRMATION_TRIES = 10;
/**
* Maximum number of attempts we will make trying to register with Eureka (via POST)
*/
public static final int MAX_REGISTRATION_ATTEMPTS = 60;
/**
* Value for delay to wait if a call to Eureka fails.
*/
private static final long RETRY_DELAY = 1;
/**
* Unit for delay to wait if a call to Eureka fails.
*/
private static final TimeUnit RETRY_DELAY_UNIT = TimeUnit.SECONDS;
/**
* Value for delay when un-registering if a call to Eureka fails.
*/
private static final long UNREGISTER_RETRY_DELAY = 3;
/**
* Time unit for delay when un-registering if a call to Eureka fails.
*/
private static final TimeUnit UNREGISTER_RETRY_DELAY_UNIT = TimeUnit.SECONDS;
/**
* Maximum number of attempts we will make to un-register from Eureka (via DELETE request).
*/
private static final int MAX_UNREGISTER_ATTEMPTS = 5;
/**
* Maximum number of attempts we will make to update status in Eureka (via PUT request).
*/
private static final int MAX_UPDATE_STATUS_ATTEMPTS = 5;
private final EurekaRegistrationConfig config;
private final EurekaRestClient client;
private final SimpleRetryer registerRetryer;
private final SimpleRetryer awaitRetryer;
private final SimpleRetryer updateStatusRetryer;
private final SimpleRetryer unregisterRetryer;
private final KiwiEnvironment environment;
private final EurekaUrlProvider urlProvider;
@VisibleForTesting
@Getter(AccessLevel.PACKAGE)
final AtomicReference registeredInstance;
@VisibleForTesting
final AtomicReference heartbeatExecutor;
public EurekaRegistryService(EurekaRegistrationConfig config, EurekaRestClient client, KiwiEnvironment environment) {
this.config = config;
this.client = client;
this.environment = environment;
this.urlProvider = new EurekaUrlProvider(config.getRegistryUrls());
this.registeredInstance = new AtomicReference<>();
this.heartbeatExecutor = new AtomicReference<>();
this.registerRetryer = SimpleRetryer.builder()
.environment(environment)
.maxAttempts(MAX_REGISTRATION_ATTEMPTS)
.retryDelayTime(RETRY_DELAY)
.retryDelayUnit(RETRY_DELAY_UNIT)
.build();
this.awaitRetryer = SimpleRetryer.builder()
.environment(environment)
.maxAttempts(MAX_AWAIT_REGISTRATION_CONFIRMATION_TRIES)
.retryDelayTime(RETRY_DELAY)
.retryDelayUnit(RETRY_DELAY_UNIT)
.build();
this.updateStatusRetryer = SimpleRetryer.builder()
.environment(environment)
.maxAttempts(MAX_UPDATE_STATUS_ATTEMPTS)
.retryDelayTime(RETRY_DELAY)
.retryDelayUnit(RETRY_DELAY_UNIT)
.build();
this.unregisterRetryer = SimpleRetryer.builder()
.environment(environment)
.maxAttempts(MAX_UNREGISTER_ATTEMPTS)
.retryDelayTime(UNREGISTER_RETRY_DELAY)
.retryDelayUnit(UNREGISTER_RETRY_DELAY_UNIT)
.build();
}
@Override
public ServiceInstance createCandidateFrom(ServiceInfo serviceInfo) {
return ServiceInstance.fromServiceInfo(serviceInfo)
.withStatus(Status.STARTING);
}
@Override
public ServiceInstance register(ServiceInstance serviceToRegister) {
checkState(isNotRegistered(), "Cannot register. Already managing a registered instance: %s", registeredInstance.get());
// NOTE: We are calling `toUpperCase()` because the Eureka server will do it on the server side anyways, so this keeps it consistent here.
var appId = f("{}-{}", serviceToRegister.getServiceName(), APP_TIMESTAMP_FORMATTER.format(environment.currentInstant()))
.toUpperCase(Locale.getDefault());
registerWithEureka(appId, serviceToRegister);
var registeredInstanceFromEureka = waitForInstanceToBeRegistered(appId, serviceToRegister.getHostName());
// I'm pretty sure this can never happen since waitForInstanceToBeRegistered will throw an exception after the retries run out
if (isNull(registeredInstanceFromEureka)) {
return null;
}
registeredInstance.set(registeredInstanceFromEureka);
LOG.info("Successful registration of app {}, instance {} with vip address {}",
registeredInstanceFromEureka.getApp(), registeredInstanceFromEureka.getInstanceId(), registeredInstanceFromEureka.getVipAddress());
startHeartbeat();
var includeNativeData = config.isIncludeNativeData()
? NativeRegistryData.INCLUDE_NATIVE_DATA : NativeRegistryData.IGNORE_NATIVE_DATA;
return registeredInstanceFromEureka.toServiceInstance(includeNativeData);
}
private void startHeartbeat() {
if (nonNull(heartbeatExecutor.get())) {
shutdownHeartbeat();
}
var heartbeatInterval = config.getHeartbeatIntervalInSeconds();
LOG.debug("Starting heartbeat with interval {} seconds", heartbeatInterval);
heartbeatExecutor.set(newHeartbeatExecutor());
heartbeatExecutor.get().scheduleWithFixedDelay(new EurekaHeartbeatSender(client, this, registeredInstance.get(), urlProvider),
heartbeatInterval, heartbeatInterval, TimeUnit.SECONDS);
}
private void shutdownHeartbeat() {
var executor = heartbeatExecutor.get();
if (isNull(executor)) {
LOG.trace("Heartbeat executor was null; nothing to shut down.");
return;
}
LOG.info("Shutting heartbeat executor down: {}", executor);
var tasks = executor.shutdownNow();
if (isNotNullOrEmpty(tasks)) {
LOG.info("There are {} task(s) that never started for heartbeat executor: {}", tasks.size(), executor);
}
try {
var terminated = executor.awaitTermination(5, TimeUnit.SECONDS);
LOG.info("Heartbeat executor {} terminated before timeout? {}", executor, terminated);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
LOG.warn("Interrupted waiting for termination of heartbeat executor {}", executor);
}
heartbeatExecutor.set(null);
}
private static ScheduledExecutorService newHeartbeatExecutor() {
var threadFactory = new ThreadFactoryBuilder()
.setNameFormat("eureka-heartbeat-%d")
.setDaemon(true)
.build();
return Executors.newScheduledThreadPool(1, threadFactory);
}
private void registerWithEureka(String appId, ServiceInstance serviceToRegister) {
var eurekaInstance = EurekaInstance.fromServiceInstance(serviceToRegister)
.withApp(appId)
.withStatus(Status.UP.name())
.withDataCenterInfo(Map.of(
"name", DEFAULT_DATA_CENTER_NAME,
"@class", DEFAULT_DATA_CENTER_INFO_CLASS
))
.withLeaseInfo(Map.of(
LEASE_DURATION_IN_SECONDS, config.getExpirationIntervalInSeconds(),
LEASE_RENEWAL_INTERVAL_IN_SECONDS, config.getHeartbeatIntervalInSeconds(),
SERVICE_UP_TIMESTAMP_FIELD, System.currentTimeMillis()
));
var registrationFunction = registrationSender(appId, eurekaInstance);
var response = registerRetryer.tryGetObject(eurekaCallRetrySupplier(registrationFunction, NO_CONTENT.getStatusCode()))
.orElseThrow(() -> {
var errMsg = format("Received errors or non-204 responses on ALL %s attempts to register (via POST) with Eureka",
MAX_REGISTRATION_ATTEMPTS);
return new RegistrationException(errMsg);
});
LOG.info("Registration for app {} has been received by Eureka", appId);
LOG.debug("Response from server: Status [{}], Body {}", response.getStatus(), response.readEntity(String.class));
}
private Function registrationSender(String appId, EurekaInstance candidate) {
return eurekaUrl -> {
try {
return client.register(eurekaUrl, appId, candidate);
} catch (Exception e) {
LOG.error("Failed to register app {} with body {} to Eureka at {}", appId, candidate, eurekaUrl, e);
return null;
}
};
}
private EurekaInstance waitForInstanceToBeRegistered(String appId, String instanceId) {
LOG.debug("Wait for registration to show in Eureka for app {}, instance {}", appId, instanceId);
var instanceGetterFunction = instanceRequester(appId, instanceId);
var response = awaitRetryer.tryGetObject(eurekaCallRetrySupplier(instanceGetterFunction, OK.getStatusCode()));
return response
.map(resp -> resp.readEntity(new GenericType>(){}).get("instance"))
.orElseThrow(() -> {
LOG.error("Registration failed, or there is some other problem getting app {}, instance {}", appId, instanceId);
var errMsg = format("Unable to obtain app %s, instance %s from Eureka during registration after %s attempts",
appId, instanceId, MAX_AWAIT_REGISTRATION_CONFIRMATION_TRIES);
return new RegistrationException(errMsg);
});
}
private Function instanceRequester(String appId, String instanceId) {
return eurekaUrl -> {
try {
return client.findInstance(eurekaUrl, appId, instanceId);
} catch (Exception e) {
LOG.error("Failed to get instance with appId {}, instanceId {} from Eureka at {} due to unexpected exception", appId, instanceId, eurekaUrl, e);
return null;
}
};
}
@Override
public ServiceInstance updateStatus(Status newStatus) {
checkState(isRegistered(), "Can not update status before calling register");
var instanceToUnregister = registeredInstance.get();
var appId = instanceToUnregister.getApp();
var instanceId = instanceToUnregister.getInstanceId();
var response = updateStatusRetryer.tryGetObject(eurekaCallRetrySupplier(
updateStatusSender(appId, instanceId, newStatus), OK.getStatusCode()));
Optionals.ifPresentOrElseThrow(response,
resp -> {
LOG.info("Instance with appId {}, instanceId {} has been updated successfully to status {}", appId, instanceId, newStatus);
registeredInstance.set(instanceToUnregister.withStatus(newStatus.name()));
},
() -> {
var msg = format("Error updating status for app {}, instance {}", appId, instanceId);
LOG.error(msg);
return new RegistrationException(msg);
});
var includeNativeData = config.isIncludeNativeData()
? NativeRegistryData.INCLUDE_NATIVE_DATA : NativeRegistryData.IGNORE_NATIVE_DATA;
return registeredInstance.get().toServiceInstance(includeNativeData);
}
private Function updateStatusSender(String appId, String instanceId, Status newStatus) {
return eurekaUrl -> {
try {
return client.updateStatus(eurekaUrl, appId, instanceId, newStatus);
} catch (Exception e) {
LOG.error("Failed to update status to {} for instance with appId {}, instanceId {} from Eureka at {} due to unexpected exception",
newStatus, appId, instanceId, eurekaUrl, e);
return null;
}
};
}
@Override
public void unregister() {
shutdownHeartbeat();
if (isNotRegistered()) {
LOG.warn("Ignoring un-register request because not currently registered (call register first)");
return;
}
unregisterFromEureka();
}
private void unregisterFromEureka() {
var instanceToUnregister = registeredInstance.get();
var appId = instanceToUnregister.getApp();
var instanceId = instanceToUnregister.getInstanceId();
var response = unregisterRetryer.tryGetObject(eurekaCallRetrySupplier(
unregisterSender(appId, instanceId), OK.getStatusCode()));
Optionals.ifPresentOrElseThrow(response,
resp -> {
LOG.info("Instance with appId {}, instanceId {} has been unregistered successfully", appId, instanceId);
registeredInstance.set(null);
},
() -> {
var msg = format("Error un-registering app {}, instance {}", appId, instanceId);
LOG.error(msg);
return new RegistrationException(msg);
});
}
private Function unregisterSender(String appId, String instanceId) {
return eurekaUrl -> {
try {
return client.unregister(eurekaUrl, appId, instanceId);
} catch (Exception e) {
LOG.error("Failed to unregister instance with appId {}, instanceId {} from Eureka at {} due to unexpected exception", appId, instanceId, eurekaUrl, e);
return null;
}
};
}
private boolean isRegistered() {
return nonNull(registeredInstance.get());
}
private boolean isNotRegistered() {
return !isRegistered();
}
private Supplier eurekaCallRetrySupplier(Function restCallFunction, int successfulStatusCode) {
return () -> {
var eurekaUrl = urlProvider.getCurrentEurekaUrl();
LOG.debug("Attempting a call to Eureka");
var response = restCallFunction.apply(eurekaUrl);
if (isNull(response)) {
urlProvider.getNextEurekaUrl();
LOG.error("Call to Eureka failed. See previous error for details");
return null;
}
if (successfulStatusCode == response.getStatus()) {
return response;
}
urlProvider.getNextEurekaUrl();
LOG.error("HTTP {} - Call to Eureka at {} failed to respond successfully. Response body: {}",
response.getStatus(), eurekaUrl, response.readEntity(String.class));
return null;
};
}
void clearRegisteredInstance() {
registeredInstance.set(null);
}
}