org.apache.camel.impl.health.DefaultHealthCheckService Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of camel-core Show documentation
Show all versions of camel-core Show documentation
The Core Camel Java DSL based router
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.camel.impl.health;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.StampedLock;
import java.util.function.BiConsumer;
import java.util.stream.Collectors;
import org.apache.camel.CamelContext;
import org.apache.camel.health.HealthCheck;
import org.apache.camel.health.HealthCheckHelper;
import org.apache.camel.health.HealthCheckRegistry;
import org.apache.camel.health.HealthCheckService;
import org.apache.camel.support.ServiceSupport;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.util.concurrent.LockHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public final class DefaultHealthCheckService extends ServiceSupport implements HealthCheckService {
private static final Logger LOGGER = LoggerFactory.getLogger(DefaultHealthCheckService.class);
private final ConcurrentMap checks;
private final ConcurrentMap> options;
private final List> listeners;
private final StampedLock lock;
private CamelContext camelContext;
private ScheduledExecutorService executorService;
private long checkInterval;
private TimeUnit checkIntervalUnit;
private volatile HealthCheckRegistry registry;
private volatile ScheduledFuture future;
public DefaultHealthCheckService() {
this(null);
}
public DefaultHealthCheckService(CamelContext camelContext) {
this.checks = new ConcurrentHashMap<>();
this.options = new ConcurrentHashMap<>();
this.listeners = new ArrayList<>();
this.lock = new StampedLock();
this.camelContext = camelContext;
this.checkInterval = 30;
this.checkIntervalUnit = TimeUnit.SECONDS;
}
// ************************************
// Properties
// ************************************
@Override
public void setCamelContext(CamelContext camelContext) {
this.camelContext = camelContext;
}
@Override
public CamelContext getCamelContext() {
return camelContext;
}
public HealthCheckRegistry getHealthCheckRegistry() {
return registry;
}
public void setHealthCheckRegistry(HealthCheckRegistry registry) {
this.registry = registry;
}
public long getCheckInterval() {
return checkInterval;
}
public void setCheckInterval(long checkInterval) {
this.checkInterval = checkInterval;
}
public void setCheckInterval(long interval, TimeUnit intervalUnit) {
setCheckInterval(interval);
setCheckIntervalUnit(intervalUnit);
}
public TimeUnit getCheckIntervalUnit() {
return checkIntervalUnit;
}
public void setCheckIntervalUnit(TimeUnit checkIntervalUnit) {
this.checkIntervalUnit = checkIntervalUnit;
}
@Override
public void addStateChangeListener(BiConsumer consumer) {
LockHelper.doWithWriteLock(
lock,
() -> listeners.add(consumer)
);
}
@Override
public void removeStateChangeListener(BiConsumer consumer) {
LockHelper.doWithWriteLock(
lock,
() -> listeners.removeIf(listener -> listener.equals(consumer))
);
}
@Override
public void setHealthCheckOptions(String id, Map options) {
options.put(id, options);
}
@Override
public Optional call(String id) {
return call(id, options.getOrDefault(id, Collections.emptyMap()));
}
@Override
public Optional call(String id, Map options) {
return registry.getCheck(id).map(check -> invoke(check, options));
}
@Override
public void notify(HealthCheck check, HealthCheck.Result result) {
LockHelper.doWithWriteLock(
lock,
() -> processResult(check, result)
);
}
@Override
public Collection getResults() {
return new ArrayList<>(this.checks.values());
}
// ************************************
// Lifecycle
// ************************************
@Override
protected void doStart() throws Exception {
ObjectHelper.notNull(camelContext, "CamelContext");
if (executorService == null) {
executorService = camelContext.getExecutorServiceManager().newSingleThreadScheduledExecutor(this, "DefaultHealthCheckService");
}
if (future != null) {
future.cancel(true);
}
if (registry == null) {
registry = camelContext.getHealthCheckRegistry();
}
if (ObjectHelper.isNotEmpty(registry) && ObjectHelper.isEmpty(future)) {
// Start the health check task only if the health check registry
// has been registered.
LOGGER.debug("Schedule health-checks to be executed every %d (%s)", checkInterval, checkIntervalUnit.name());
future = executorService.scheduleAtFixedRate(
() -> {
if (!isRunAllowed()) {
// do not invoke the check if the service is not yet
// properly started.
return;
}
LOGGER.debug("Invoke health-checks (scheduled)");
registry.stream()
.collect(Collectors.groupingBy(HealthCheckHelper::getGroup))
.entrySet().stream()
.map(Map.Entry::getValue)
.flatMap(Collection::stream)
.sorted(Comparator.comparingInt(HealthCheck::getOrder))
.forEach(this::invoke);
},
checkInterval,
checkInterval,
checkIntervalUnit);
}
}
@Override
protected void doStop() throws Exception {
if (future != null) {
future.cancel(true);
future = null;
}
if (executorService != null) {
if (camelContext != null) {
camelContext.getExecutorServiceManager().shutdownNow(executorService);
} else {
executorService.shutdownNow();
}
executorService = null;
}
}
// ************************************
// Helpers
// ************************************
private HealthCheck.Result processResult(HealthCheck check, HealthCheck.Result result) {
final HealthCheck.Result cachedResult = checks.get(check);
if (!isSameResult(result, cachedResult)) {
// Maybe make the listener aware of the reason, i.e.
// the service is still un-healthy but the message
// or error has changed.
listeners.forEach(listener -> listener.accept(result.getState(), check));
}
// replace the old result with the new one even if the
// state has not changed but the reason/error may be
// changed.
checks.put(check, result);
return result;
}
private HealthCheck.Result invoke(HealthCheck check) {
return invoke(check, options.getOrDefault(check.getId(), Collections.emptyMap()));
}
private HealthCheck.Result invoke(HealthCheck check, Map options) {
return LockHelper.supplyWithWriteLock(
lock,
() -> {
LOGGER.debug("Invoke health-check {}", check.getId());
return processResult(check, check.call(options));
}
);
}
/**
* Check if two results are equals by checking only the state, this method
* does not check if the result comes from the same health check, this should
* be done by the caller.
*
* A future implementation should check all the parameter of the result.
*/
private boolean isSameResult(HealthCheck.Result r1, HealthCheck.Result r2) {
if (Objects.equals(r1, r2)) {
return true;
}
if (r1 != null && r2 != null) {
return r1.getState() == r2.getState();
}
return false;
}
}