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ActiveMQ example source code file (AbortSlowConsumerStrategy.java)

This example ActiveMQ source code file (AbortSlowConsumerStrategy.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - ActiveMQ tags/keywords

abortslowconsumerstrategy, atomicboolean, consumercontrol, entry, entry, hashmap, hashmap, map, map, runnable, slowconsumerentry, slowconsumerentry, slowconsumerstrategy, string, threading, threads, util

The ActiveMQ AbortSlowConsumerStrategy.java source code

/**
 * 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.activemq.broker.region.policy;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.activemq.broker.Broker;
import org.apache.activemq.broker.Connection;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.broker.region.Subscription;
import org.apache.activemq.command.ConsumerControl;
import org.apache.activemq.thread.Scheduler;
import org.apache.activemq.transport.InactivityIOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Abort slow consumers when they reach the configured threshold of slowness, default is slow for 30 seconds
 * 
 * @org.apache.xbean.XBean
 */
public class AbortSlowConsumerStrategy implements SlowConsumerStrategy, Runnable {
    
    private static final Logger LOG = LoggerFactory.getLogger(AbortSlowConsumerStrategy.class);

    private String name = "AbortSlowConsumerStrategy@" + hashCode();
    private Scheduler scheduler;
    private Broker broker;
    private final AtomicBoolean taskStarted = new AtomicBoolean(false);
    private final Map<Subscription, SlowConsumerEntry> slowConsumers = new ConcurrentHashMap();

    private long maxSlowCount = -1;
    private long maxSlowDuration = 30*1000;
    private long checkPeriod = 30*1000;
    private boolean abortConnection = false;

    public void setBrokerService(Broker broker) {
       this.scheduler = broker.getScheduler();
       this.broker = broker;
    }

    public void slowConsumer(ConnectionContext context, Subscription subs) {
        if (maxSlowCount < 0 && maxSlowDuration < 0) {
            // nothing to do
            LOG.info("no limits set, slowConsumer strategy has nothing to do");
            return;
        }
        
        if (taskStarted.compareAndSet(false, true)) {
            scheduler.executePeriodically(this, checkPeriod);
        }
            
        if (!slowConsumers.containsKey(subs)) {
            slowConsumers.put(subs, new SlowConsumerEntry(context));
        } else if (maxSlowCount > 0) {
            slowConsumers.get(subs).slow();
        }
    }

    public void run() {
        if (maxSlowDuration > 0) {
            // mark
            for (SlowConsumerEntry entry : slowConsumers.values()) {
                entry.mark();
            }
        }
        
        HashMap<Subscription, SlowConsumerEntry> toAbort = new HashMap();
        for (Entry<Subscription, SlowConsumerEntry> entry : slowConsumers.entrySet()) {
            if (entry.getKey().isSlowConsumer()) {
                if (maxSlowDuration > 0 && (entry.getValue().markCount * checkPeriod > maxSlowDuration)
                        || maxSlowCount > 0 && entry.getValue().slowCount > maxSlowCount) { 
                    toAbort.put(entry.getKey(), entry.getValue());
                    slowConsumers.remove(entry.getKey());
                }
            } else {
                LOG.info("sub: " + entry.getKey().getConsumerInfo().getConsumerId() + " is no longer slow");
                slowConsumers.remove(entry.getKey());
            }
        }

        abortSubscription(toAbort, abortConnection);
    }

    private void abortSubscription(Map<Subscription, SlowConsumerEntry> toAbort, boolean abortSubscriberConnection) {
        for (final Entry<Subscription, SlowConsumerEntry> entry : toAbort.entrySet()) {
            ConnectionContext connectionContext = entry.getValue().context;
            if (connectionContext!= null) {
                try {
                    LOG.info("aborting "
                            + (abortSubscriberConnection ? "connection" : "consumer") 
                            + ", slow consumer: " + entry.getKey().getConsumerInfo().getConsumerId());

                    final Connection connection = connectionContext.getConnection();
                    if (connection != null) {
                        if (abortSubscriberConnection) {
                            scheduler.executeAfterDelay(new Runnable() {
                                public void run() {
                                    connection.serviceException(new InactivityIOException("Consumer was slow too often (>"
                                            + maxSlowCount +  ") or too long (>"
                                            + maxSlowDuration + "): " + entry.getKey().getConsumerInfo().getConsumerId()));
                                }}, 0l);
                        } else {
                            // just abort the consumer by telling it to stop
                            ConsumerControl stopConsumer = new ConsumerControl();
                            stopConsumer.setConsumerId(entry.getKey().getConsumerInfo().getConsumerId());
                            stopConsumer.setClose(true);
                            connection.dispatchAsync(stopConsumer);
                        }
                    } else {
                        LOG.debug("slowConsumer abort ignored, no connection in context:"  + connectionContext);
                    }
                } catch (Exception e) {
                    LOG.info("exception on stopping "
                            + (abortSubscriberConnection ? "connection" : "consumer")
                            + " to abort slow consumer: " + entry.getKey(), e);
                }
            }
        }
    }


    public void abortConsumer(Subscription sub, boolean abortSubscriberConnection) {
        if (sub != null) {
            SlowConsumerEntry entry = slowConsumers.remove(sub);
            if (entry != null) {
                Map toAbort = new HashMap<Subscription, SlowConsumerEntry>();
                toAbort.put(sub, entry);
                abortSubscription(toAbort, abortSubscriberConnection);
            } else {
                LOG.warn("cannot abort subscription as it no longer exists in the map of slow consumers: " + sub);
            }
        }
    }


    public long getMaxSlowCount() {
        return maxSlowCount;
    }

    /**
     * number of times a subscription can be deemed slow before triggering abort
     * effect depends on dispatch rate as slow determination is done on dispatch
     */
    public void setMaxSlowCount(long maxSlowCount) {
        this.maxSlowCount = maxSlowCount;
    }

    public long getMaxSlowDuration() {
        return maxSlowDuration;
    }

    /**
     * time in milliseconds that a sub can remain slow before triggering
     * an abort.
     * @param maxSlowDuration
     */
    public void setMaxSlowDuration(long maxSlowDuration) {
        this.maxSlowDuration = maxSlowDuration;
    }

    public long getCheckPeriod() {
        return checkPeriod;
    }

    /**
     * time in milliseconds between checks for slow subscriptions
     * @param checkPeriod
     */
    public void setCheckPeriod(long checkPeriod) {
        this.checkPeriod = checkPeriod;
    }

    public boolean isAbortConnection() {
        return abortConnection;
    }

    /**
     * abort the consumers connection rather than sending a stop command to the remote consumer
     * @param abortConnection
     */
    public void setAbortConnection(boolean abortConnection) {
        this.abortConnection = abortConnection;
    }

    public void setName(String name) {
        this.name = name;
    }
    
    public String getName() {
        return name;
    }

    public Map<Subscription, SlowConsumerEntry> getSlowConsumers() {
        return slowConsumers;
    }
}

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