io.micronaut.health.HeartbeatTask Maven / Gradle / Ivy
/*
* Copyright 2017-2020 original authors
*
* 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 io.micronaut.health;
import io.micronaut.context.event.ApplicationEventListener;
import io.micronaut.context.event.ApplicationEventPublisher;
import io.micronaut.discovery.ServiceInstance;
import io.micronaut.discovery.event.ServiceReadyEvent;
import io.micronaut.scheduling.annotation.Scheduled;
import javax.inject.Singleton;
import java.util.concurrent.atomic.AtomicReference;
/**
* A scheduled task that sends a periodic heartbeat whilst the server is active.
*
* @author graemerocher
* @since 1.0
*/
@Singleton
@HeartbeatEnabled
public class HeartbeatTask implements ApplicationEventListener {
private AtomicReference eventReference = new AtomicReference<>();
private final ApplicationEventPublisher eventPublisher;
private final HeartbeatConfiguration configuration;
private final CurrentHealthStatus currentHealthStatus;
/**
* @param eventPublisher To publish the events related to heartbeat
* @param configuration The configurations for heartbeat
* @param currentHealthStatus The current status of health indicator
*/
public HeartbeatTask(ApplicationEventPublisher eventPublisher, HeartbeatConfiguration configuration, CurrentHealthStatus currentHealthStatus) {
this.eventPublisher = eventPublisher;
this.configuration = configuration;
this.currentHealthStatus = currentHealthStatus;
}
/**
* Publish the heartbeat event with current health status.
*/
@Scheduled(fixedDelay = "${micronaut.heartbeat.interval:15s}",
initialDelay = "${micronaut.heartbeat.initial-delay:5s}")
public void pulsate() {
ServiceInstance instance = eventReference.get();
if (instance != null) {
eventPublisher.publishEvent(new HeartbeatEvent(instance, currentHealthStatus.current()));
}
}
@Override
public void onApplicationEvent(ServiceReadyEvent event) {
eventReference.set(event.getSource());
}
}