| /* |
| * 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.throttling; |
| |
| import java.util.LinkedHashSet; |
| import java.util.Set; |
| import java.util.concurrent.locks.Lock; |
| import java.util.concurrent.locks.ReentrantLock; |
| |
| import org.apache.camel.CamelContext; |
| import org.apache.camel.CamelContextAware; |
| import org.apache.camel.Consumer; |
| import org.apache.camel.Exchange; |
| import org.apache.camel.LoggingLevel; |
| import org.apache.camel.Route; |
| import org.apache.camel.spi.CamelEvent; |
| import org.apache.camel.spi.CamelEvent.ExchangeCompletedEvent; |
| import org.apache.camel.spi.CamelLogger; |
| import org.apache.camel.support.EventNotifierSupport; |
| import org.apache.camel.support.RoutePolicySupport; |
| import org.apache.camel.support.service.ServiceHelper; |
| import org.apache.camel.util.ObjectHelper; |
| |
| /** |
| * A throttle based {@link org.apache.camel.spi.RoutePolicy} which is capable of dynamic |
| * throttling a route based on number of current inflight exchanges. |
| * <p/> |
| * This implementation supports two scopes {@link ThrottlingScope#Context} and {@link ThrottlingScope#Route} (is default). |
| * If context scope is selected then this implementation will use a {@link org.apache.camel.spi.EventNotifier} to listen |
| * for events when {@link Exchange}s is done, and trigger the {@link #throttle(org.apache.camel.Route, org.apache.camel.Exchange)} |
| * method. If the route scope is selected then <b>no</b> {@link org.apache.camel.spi.EventNotifier} is in use, as there is already |
| * a {@link org.apache.camel.spi.Synchronization} callback on the current {@link Exchange} which triggers the |
| * {@link #throttle(org.apache.camel.Route, org.apache.camel.Exchange)} when the current {@link Exchange} is done. |
| */ |
| public class ThrottlingInflightRoutePolicy extends RoutePolicySupport implements CamelContextAware { |
| |
| public enum ThrottlingScope { |
| Context, Route |
| } |
| |
| private final Set<Route> routes = new LinkedHashSet<>(); |
| private ContextScopedEventNotifier eventNotifier; |
| private CamelContext camelContext; |
| private final Lock lock = new ReentrantLock(); |
| private ThrottlingScope scope = ThrottlingScope.Route; |
| private int maxInflightExchanges = 1000; |
| private int resumePercentOfMax = 70; |
| private int resumeInflightExchanges = 700; |
| private LoggingLevel loggingLevel = LoggingLevel.INFO; |
| private CamelLogger logger; |
| |
| public ThrottlingInflightRoutePolicy() { |
| } |
| |
| @Override |
| public String toString() { |
| return "ThrottlingInflightRoutePolicy[" + maxInflightExchanges + " / " + resumePercentOfMax + "% using scope " + scope + "]"; |
| } |
| |
| public CamelContext getCamelContext() { |
| return camelContext; |
| } |
| |
| public void setCamelContext(CamelContext camelContext) { |
| this.camelContext = camelContext; |
| } |
| |
| @Override |
| public void onInit(Route route) { |
| // we need to remember the routes we apply for |
| routes.add(route); |
| } |
| |
| @Override |
| public void onExchangeDone(Route route, Exchange exchange) { |
| // if route scoped then throttle directly |
| // as context scoped is handled using an EventNotifier instead |
| if (scope == ThrottlingScope.Route) { |
| throttle(route, exchange); |
| } |
| } |
| |
| /** |
| * Throttles the route when {@link Exchange}s is done. |
| * |
| * @param route the route |
| * @param exchange the exchange |
| */ |
| protected void throttle(Route route, Exchange exchange) { |
| // this works the best when this logic is executed when the exchange is done |
| Consumer consumer = route.getConsumer(); |
| |
| int size = getSize(route, exchange); |
| boolean stop = maxInflightExchanges > 0 && size > maxInflightExchanges; |
| if (log.isTraceEnabled()) { |
| log.trace("{} > 0 && {} > {} evaluated as {}", maxInflightExchanges, size, maxInflightExchanges, stop); |
| } |
| if (stop) { |
| try { |
| lock.lock(); |
| stopConsumer(size, consumer); |
| } catch (Exception e) { |
| handleException(e); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| // reload size in case a race condition with too many at once being invoked |
| // so we need to ensure that we read the most current size and start the consumer if we are already to low |
| size = getSize(route, exchange); |
| boolean start = size <= resumeInflightExchanges; |
| if (log.isTraceEnabled()) { |
| log.trace("{} <= {} evaluated as {}", size, resumeInflightExchanges, start); |
| } |
| if (start) { |
| try { |
| lock.lock(); |
| startConsumer(size, consumer); |
| } catch (Exception e) { |
| handleException(e); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| } |
| |
| public int getMaxInflightExchanges() { |
| return maxInflightExchanges; |
| } |
| |
| /** |
| * Sets the upper limit of number of concurrent inflight exchanges at which point reached |
| * the throttler should suspend the route. |
| * <p/> |
| * Is default 1000. |
| * |
| * @param maxInflightExchanges the upper limit of concurrent inflight exchanges |
| */ |
| public void setMaxInflightExchanges(int maxInflightExchanges) { |
| this.maxInflightExchanges = maxInflightExchanges; |
| // recalculate, must be at least at 1 |
| this.resumeInflightExchanges = Math.max(resumePercentOfMax * maxInflightExchanges / 100, 1); |
| } |
| |
| public int getResumePercentOfMax() { |
| return resumePercentOfMax; |
| } |
| |
| /** |
| * Sets at which percentage of the max the throttler should start resuming the route. |
| * <p/> |
| * Will by default use 70%. |
| * |
| * @param resumePercentOfMax the percentage must be between 0 and 100 |
| */ |
| public void setResumePercentOfMax(int resumePercentOfMax) { |
| if (resumePercentOfMax < 0 || resumePercentOfMax > 100) { |
| throw new IllegalArgumentException("Must be a percentage between 0 and 100, was: " + resumePercentOfMax); |
| } |
| |
| this.resumePercentOfMax = resumePercentOfMax; |
| // recalculate, must be at least at 1 |
| this.resumeInflightExchanges = Math.max(resumePercentOfMax * maxInflightExchanges / 100, 1); |
| } |
| |
| public ThrottlingScope getScope() { |
| return scope; |
| } |
| |
| /** |
| * Sets which scope the throttling should be based upon, either route or total scoped. |
| * |
| * @param scope the scope |
| */ |
| public void setScope(ThrottlingScope scope) { |
| this.scope = scope; |
| } |
| |
| public LoggingLevel getLoggingLevel() { |
| return loggingLevel; |
| } |
| |
| public CamelLogger getLogger() { |
| if (logger == null) { |
| logger = createLogger(); |
| } |
| return logger; |
| } |
| |
| /** |
| * Sets the logger to use for logging throttling activity. |
| * |
| * @param logger the logger |
| */ |
| public void setLogger(CamelLogger logger) { |
| this.logger = logger; |
| } |
| |
| /** |
| * Sets the logging level to report the throttling activity. |
| * <p/> |
| * Is default <tt>INFO</tt> level. |
| * |
| * @param loggingLevel the logging level |
| */ |
| public void setLoggingLevel(LoggingLevel loggingLevel) { |
| this.loggingLevel = loggingLevel; |
| } |
| |
| protected CamelLogger createLogger() { |
| return new CamelLogger(log, getLoggingLevel()); |
| } |
| |
| private int getSize(Route route, Exchange exchange) { |
| if (scope == ThrottlingScope.Context) { |
| return exchange.getContext().getInflightRepository().size(); |
| } else { |
| return exchange.getContext().getInflightRepository().size(route.getId()); |
| } |
| } |
| |
| private void startConsumer(int size, Consumer consumer) throws Exception { |
| boolean started = resumeOrStartConsumer(consumer); |
| if (started) { |
| getLogger().log("Throttling consumer: " + size + " <= " + resumeInflightExchanges + " inflight exchange by resuming consumer: " + consumer); |
| } |
| } |
| |
| private void stopConsumer(int size, Consumer consumer) throws Exception { |
| boolean stopped = suspendOrStopConsumer(consumer); |
| if (stopped) { |
| getLogger().log("Throttling consumer: " + size + " > " + maxInflightExchanges + " inflight exchange by suspending consumer: " + consumer); |
| } |
| } |
| |
| @Override |
| protected void doStart() throws Exception { |
| ObjectHelper.notNull(camelContext, "CamelContext", this); |
| if (scope == ThrottlingScope.Context) { |
| eventNotifier = new ContextScopedEventNotifier(); |
| // must start the notifier before it can be used |
| ServiceHelper.startService(eventNotifier); |
| // we are in context scope, so we need to use an event notifier to keep track |
| // when any exchanges is done on the camel context. |
| // This ensures we can trigger accordingly to context scope |
| camelContext.getManagementStrategy().addEventNotifier(eventNotifier); |
| } |
| } |
| |
| @Override |
| protected void doStop() throws Exception { |
| ObjectHelper.notNull(camelContext, "CamelContext", this); |
| if (scope == ThrottlingScope.Context) { |
| camelContext.getManagementStrategy().removeEventNotifier(eventNotifier); |
| } |
| } |
| |
| /** |
| * {@link org.apache.camel.spi.EventNotifier} to keep track on when {@link Exchange} |
| * is done, so we can throttle accordingly. |
| */ |
| private class ContextScopedEventNotifier extends EventNotifierSupport { |
| |
| @Override |
| public void notify(CamelEvent event) throws Exception { |
| ExchangeCompletedEvent completedEvent = (ExchangeCompletedEvent) event; |
| for (Route route : routes) { |
| throttle(route, completedEvent.getExchange()); |
| } |
| } |
| |
| @Override |
| public boolean isEnabled(CamelEvent event) { |
| return event instanceof ExchangeCompletedEvent; |
| } |
| |
| @Override |
| public String toString() { |
| return "ContextScopedEventNotifier"; |
| } |
| } |
| |
| } |