ActiveMQ KahaDB always locking and waiting

Question

I am trying to use ActiveMQ in a relatively simple work queue use case. I have one queue, and have a simple Producer and Consumer. My question is what am I doing wrong that continuously makes the DB lock? here is the message I get continously:

14/04/05 18:14:13 INFO store.SharedFileLocker: Database activemq-data\localhost\KahaDB\lock is locked... waiting 10 seconds for the database to be unlocked. Reason: java.io.IOException: File 'activemq-data\localhost\KahaDB\lock' could not be locked.

I am running the producer and consumer in separate threads at the same time. Initially, I had the connection at the class level, so I thought that was the problem, but even creating the connection from scratch every call to put and get still causes locking.

I have done research but have failed to find a solution. I am running ActiveMQ 5.9.0 on windows 7.

Here is what prints out when I start it via cmd prompt:

C:\activemq\apache-activemq-5.9.0\bin>activemq
Java Runtime: Oracle Corporation 1.7.0_40 C:\Program Files\Java\jre7
  Heap sizes: current=1005568k  free=995061k  max=1005568k
    JVM args: -Dcom.sun.management.jmxremote -Xms1G -Xmx1G -Djava.util.logging.config.file=logging.properties -Dhawtio.realm=activemq -Dhawtio.role=admins -Dhawtio.rolePrincipalCla
vemq.jaas.GroupPrincipal -Djava.security.auth.login.config=C:\activemq\apache-activemq-5.9.0\bin\..\conf\login.config -Dactivemq.classpath=C:\activemq\apache-activemq-5.9.0\bin\..\
che-activemq-5.9.0\bin\../conf;C:\activemq\apache-activemq-5.9.0\bin\../conf; -Dactivemq.home=C:\activemq\apache-activemq-5.9.0\bin\.. -Dactivemq.base=C:\activemq\apache-activemq-5
mq.conf=C:\activemq\apache-activemq-5.9.0\bin\..\conf -Dactivemq.data=C:\activemq\apache-activemq-5.9.0\bin\..\data -Djava.io.tmpdir=C:\activemq\apache-activemq-5.9.0\bin\..\data\t
Extensions classpath:
  [C:\activemq\apache-activemq-5.9.0\bin\..\lib,C:\activemq\apache-activemq-5.9.0\bin\..\lib\camel,C:\activemq\apache-activemq-5.9.0\bin\..\lib\optional,C:\activemq\apache-activemq
b,C:\activemq\apache-activemq-5.9.0\bin\..\lib\extra]
ACTIVEMQ_HOME: C:\activemq\apache-activemq-5.9.0\bin\..
ACTIVEMQ_BASE: C:\activemq\apache-activemq-5.9.0\bin\..
ACTIVEMQ_CONF: C:\activemq\apache-activemq-5.9.0\bin\..\conf
ACTIVEMQ_DATA: C:\activemq\apache-activemq-5.9.0\bin\..\data
Loading message broker from: xbean:activemq.xml
 INFO | Refreshing org.apache.activemq.xbean.XBeanBrokerFactory$1@5bf2a8f5: startup date [Sat Apr 05 17:42:42 EDT 2014]; root of context hierarchy
 INFO | PListStore:[C:\activemq\apache-activemq-5.9.0\bin\..\data\localhost\tmp_storage] started
 INFO | Using Persistence Adapter: KahaDBPersistenceAdapter[C:\activemq\apache-activemq-5.9.0\bin\..\data\kahadb]
 INFO | KahaDB is version 5
 INFO | Recovering from the journal ...
 INFO | Recovery replayed 6935 operations from the journal in 0.416 seconds.
 INFO | Apache ActiveMQ 5.9.0 (localhost, ID:Owner-PC-49614-1396734165637-0:1) is starting
 INFO | Listening for connections at: tcp://Owner-PC:61616?maximumConnections=1000&wireFormat.maxFrameSize=104857600
 INFO | Connector openwire started
 INFO | Listening for connections at: amqp://Owner-PC:5673?maximumConnections=1000&wireFormat.maxFrameSize=104857600
 INFO | Connector amqp started
 INFO | Listening for connections at: stomp://Owner-PC:61613?maximumConnections=1000&wireFormat.maxFrameSize=104857600
 INFO | Connector stomp started
 INFO | Listening for connections at: mqtt://Owner-PC:1883?maximumConnections=1000&wireFormat.maxFrameSize=104857600
 INFO | Connector mqtt started
 INFO | Listening for connections at ws://Owner-PC:61614?maximumConnections=1000&wireFormat.maxFrameSize=104857600
 INFO | Connector ws started
 INFO | Apache ActiveMQ 5.9.0 (localhost, ID:Owner-PC-49614-1396734165637-0:1) started
 INFO | For help or more information please see: http://activemq.apache.org
 INFO | Welcome to hawtio 1.2-M23 : http://hawt.io/ : Don't cha wish your console was hawt like me? ;-)
 INFO | Starting hawtio authentication filter, JAAS realm: "activemq" authorized role: "admins" role principal classes: "org.apache.activemq.jaas.GroupPrincipal"
 INFO | Using file upload directory: C:\activemq\apache-activemq-5.9.0\bin\..\data\tmp\uploads
 INFO | jolokia-agent: Using access restrictor classpath:/jolokia-access.xml
 INFO | ActiveMQ WebConsole available at http://localhost:8161/
 INFO | Initializing Spring FrameworkServlet 'dispatcher'

Here is my java to implement the Queue as ActiveMQ (I have a Queue interface and this is an Impl)

import com.google.gson.Gson;
import java.util.Set;
import javax.jms.Connection;
import javax.jms.DeliveryMode;
import javax.jms.Destination;
import javax.jms.ExceptionListener;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;

public class ActiveMQImpl implements Queue, ExceptionListener {

  private String host;
  private String user;
  private String pw;

  public void init() {
  }

  public void close() { 
  }

  public Message get() {
    Message outMessage = null;
    ActiveMQConnectionFactory connectionFactory = null;
    Connection connection = null;  
    try {
      if (connection == null) {
        connectionFactory = new ActiveMQConnectionFactory("vm://localhost");

        // Create a Connection
        connection = connectionFactory.createConnection();
      }
      connection.start();

      // Create a Session
      Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

      // Create the destination (Topic or Queue)
      Destination destination = session.createQueue("work");
      // Create a MessageConsumer from the Session to the Topic or Queue
      MessageConsumer consumer = session.createConsumer(destination);

      // Wait for a message
      javax.jms.Message message = consumer.receive(1000);

      if (message instanceof TextMessage) {
        TextMessage textMessage = (TextMessage) message;
        String text = textMessage.getText();
        outMessage = new Gson().fromJson(text, Message.class);
        //   System.out.println("Received: " + text);
      } else {
        // System.out.println("Received: " + message);
      }

      consumer.close();
      //  session.commit();
      session.close();
      //connection.close();
    } catch (Exception e) {
      System.out.println("Caught: " + e);
      e.printStackTrace();
    }
    return outMessage;
  }

  public void put(Message inMessage) {
    try {
      ActiveMQConnectionFactory connectionFactory = null;


      Connection prodConnection = null;
      connectionFactory = new ActiveMQConnectionFactory("vm://localhost");

      prodConnection = connectionFactory.createConnection();

      prodConnection.start();

      Session session = prodConnection.createSession(false, Session.AUTO_ACKNOWLEDGE);

      Destination destination = session.createQueue("work");

      MessageProducer producer = session.createProducer(destination);
      producer.setDeliveryMode(DeliveryMode.PERSISTENT);
      producer.setTimeToLive(60000);
      // Create a messages
      String text = inMessage.toString();
      TextMessage message = session.createTextMessage(text);

      // Tell the producer to send the message
      System.out.println("Sent message: " + text);
      producer.send(message);
      producer.close();
      // session.commit();
      session.close();
      prodConnection.close();
    } catch (Exception e) {
      System.out.println("Caught: " + e);
      onException(null);
      e.printStackTrace();
    }
  }

  public void onException(JMSException jmse) {
    //send this to the error channel object... 
    System.out.println(jmse);
  }

  public void put(Set<Message> messages) {
    try {
  ActiveMQConnectionFactory connectionFactory=null;
  Connection connection=null;

  Connection prodConnection=null;
      if (connection == null) {
        connectionFactory = new ActiveMQConnectionFactory("vm://localhost?jms.useAsyncSend=true");

        // Create a Connection
        connection = connectionFactory.createConnection("admin", "admin");
      }

      connection.start();

      // Create a Session
      Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

      // Create the destination (Topic or Queue)
      Destination destination = session.createQueue("work");
      // Create a MessageProducer from the Session to the Topic or Queue
      MessageProducer producer = session.createProducer(destination);
      producer.setDeliveryMode(DeliveryMode.PERSISTENT);

      // Create a messages
      for (Message inMessage : messages) {
        String text = inMessage.toString();
        TextMessage message = session.createTextMessage(text);

        // Tell the producer to send the message
        System.out.println("Sent message: " + text);
        producer.send(message);
      }
      producer.close();
      // session.commit();
      session.close();
      //connection.close();
    } catch (Exception e) {
      System.out.println("Caught: " + e);
      onException(null);
      e.printStackTrace();
    }
  }

}

Here are the producers and consumers (simple debugging classes)

public class Producer {

  public static void main(String[] args) {
    Queue q = QueueFactory.create(QueueType.ACTIVEMQ);
    try {
      for (int i = 0; i < 10; i++) {

        q.put(new Message("testimpl" + i, "whatever", i));
        Thread.sleep(1000);

      }
    } catch (InterruptedException ex) {
      Logger.getLogger(Producer.class.getName()).log(Level.SEVERE, null, ex);
    }

  }
}


public class Consumer {

  public static void main(String[] args) {

    Queue q = QueueFactory.create(QueueType.ACTIVEMQ);
    try {
      while (true) {

        Message get = q.get();
        System.out.println(get);
        Thread.sleep(1000);

      }
    } catch (InterruptedException ex) {
      Logger.getLogger(Consumer.class.getName()).log(Level.SEVERE, null, ex);
    }
  }
}

any help is appreciated.

Answer 1

do following

kill java process for active mq, open task manager -> go to process -> check for java -> and right click and say end process

then go to <activemq_install_directory>/data/kahadb

and delete lock file which gets generated

try starting activemq again

for me this works every time I face this issue

Answer 2

had the same problem. there was no other java services / brokers up and running. the problem was pretty stupid -

make sure that the user you are using has permission to write to the path of the lock file.

Answer 3

The only solution I came across to release this lock is-

1. Goto services.msc
2. Stop ActiveMQ forever (let StartUp type be Automatic)
3. you will see that the lock file disappears
4. delete the datafolder itself
5. Restart apache-activemq-5.10.0-bin\apache-activemq-5.10.0\bin\win64\activemq.bat (Not services.msc)
6. You are good to go

Answer 4

for linux just:

sudo killall java

and start again