David Dou created AMQ-6194:
------------------------------
Summary: Deleting a temporary queue creates a warning message in
the broker
Key: AMQ-6194
URL: https://issues.apache.org/jira/browse/AMQ-6194
Project: ActiveMQ
Issue Type: Bug
Components: Broker, JMS client
Affects Versions: 5.13.1, 5.12.1
Reporter: David Dou
Priority: Minor
When deleting a temporary queue, the ActiveMQ 5.13.1 (and 5.12.2) broker logs
the following warning message:
{noformat}
INFO [ActiveMQ NIO Worker 111] [TempQueue]
temp-queue://ID:brokerHostname-57582-1455804170203-8569:1:1 on dispose, purge
of 1 pending messages:
org.apache.activemq.broker.region.cursors.VMPendingMessageCursor@e0f6196
WARN [ActiveMQ NIO Worker 111] [Queue]
temp-queue://ID:brokerHostname-57582-1455804170203-8569:1:1 after purge of 1
messages, message count stats report: 1
{noformat}
The cause of this warning seems to be the publication of a "ghost" message when
sending a single message on the temporary queue from a transacted session, as
demonstrated by this test class:
{code:java}
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TemporaryQueue;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;
public class GhostMessageOnTempQueueWithTransactedSessionDemo {
public static void main(final String[] args) throws JMSException {
final ActiveMQConnectionFactory factory = new
ActiveMQConnectionFactory("tcp://localhost:61616");
Connection connection = null;
Session session = null;
MessageProducer producer = null;
TemporaryQueue temporaryQueue = null;
try {
connection = factory.createConnection();
connection.start();
// The session has to be transacted for the second "ghost" message
to appear (see below).
session = connection.createSession(true,
Session.SESSION_TRANSACTED);
// And the publication has to be on a temporary queue (if the
temporary queue is created by another process, the second "ghost" message still
appears).
temporaryQueue = session.createTemporaryQueue();
producer = session.createProducer(temporaryQueue);
final TextMessage textMessage = session.createTextMessage();
textMessage.setText("GhostMessageDemo@" + new
SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss,SSSZ").format(new Date()));
producer.send(textMessage);
// Here, in ActiveMQ 5.13.1 and 5.12.2, the message was sent but
cannot be browsed or consumed. It can however be seen in the JMX console with:
// - EnqueueCount, that was increased by one;
// - MemoryUsageByteCount (by sending huge messages of different
size to ensure that it is indeed the real message).
// In ActiveMQ 5.10.2 (and 5.4.1), it is not sent (even though
SocketOutputStream.socketWrite is still called through TcpFormat.oneway?).
session.commit();
// Here, in ActiveMQ 5.13.1, a "ghost" message was sent
(EnqueueCount has increased by one again) and the real message is visible and
can be consumed.
// If rollback is called instead, the real message stays (and
cannot be consumed since the "ghost" message is not sent).
} finally {
if (producer != null)
producer.close();
if (temporaryQueue != null)
// Here, if there was a consumer on the queue, it would have
consumed the real message, leaving the "ghost" message that lead to the broker
warning.
temporaryQueue.delete();
if (session != null)
session.close();
if (connection != null) {
connection.stop();
connection.close();
}
}
}
}
{code}
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