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/**
* 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;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import javax.jms.JMSException;
import org.apache.activemq.broker.Broker;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.broker.region.cursors.PendingMessageCursor;
import org.apache.activemq.broker.region.cursors.VMPendingMessageCursor;
import org.apache.activemq.command.ConsumerControl;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.command.Message;
import org.apache.activemq.command.MessageAck;
import org.apache.activemq.command.MessageDispatch;
import org.apache.activemq.command.MessageDispatchNotification;
import org.apache.activemq.command.MessageId;
import org.apache.activemq.command.MessagePull;
import org.apache.activemq.command.Response;
import org.apache.activemq.thread.Scheduler;
import org.apache.activemq.transaction.Synchronization;
import org.apache.activemq.transport.TransmitCallback;
import org.apache.activemq.usage.SystemUsage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A subscription that honors the pre-fetch option of the ConsumerInfo.
*/
public abstract class PrefetchSubscription extends AbstractSubscription {
private static final Logger LOG = LoggerFactory.getLogger(PrefetchSubscription.class);
protected final Scheduler scheduler;
protected PendingMessageCursor pending;
protected final List dispatched = new ArrayList();
protected final AtomicInteger prefetchExtension = new AtomicInteger();
protected boolean usePrefetchExtension = true;
protected long enqueueCounter;
protected long dispatchCounter;
protected long dequeueCounter;
private int maxProducersToAudit=32;
private int maxAuditDepth=2048;
protected final SystemUsage usageManager;
protected final Object pendingLock = new Object();
protected final Object dispatchLock = new Object();
private final CountDownLatch okForAckAsDispatchDone = new CountDownLatch(1);
public PrefetchSubscription(Broker broker, SystemUsage usageManager, ConnectionContext context, ConsumerInfo info, PendingMessageCursor cursor) throws JMSException {
super(broker,context, info);
this.usageManager=usageManager;
pending = cursor;
try {
pending.start();
} catch (Exception e) {
throw new JMSException(e.getMessage());
}
this.scheduler = broker.getScheduler();
}
public PrefetchSubscription(Broker broker,SystemUsage usageManager, ConnectionContext context, ConsumerInfo info) throws JMSException {
this(broker,usageManager,context, info, new VMPendingMessageCursor(false));
}
/**
* Allows a message to be pulled on demand by a client
*/
@Override
public Response pullMessage(ConnectionContext context, MessagePull pull) throws Exception {
// The slave should not deliver pull messages.
// TODO: when the slave becomes a master, He should send a NULL message to all the
// consumers to 'wake them up' in case they were waiting for a message.
if (getPrefetchSize() == 0) {
prefetchExtension.incrementAndGet();
final long dispatchCounterBeforePull = dispatchCounter;
// Have the destination push us some messages.
for (Destination dest : destinations) {
dest.iterate();
}
dispatchPending();
synchronized(this) {
// If there was nothing dispatched.. we may need to setup a timeout.
if (dispatchCounterBeforePull == dispatchCounter) {
// immediate timeout used by receiveNoWait()
if (pull.getTimeout() == -1) {
// Send a NULL message.
add(QueueMessageReference.NULL_MESSAGE);
dispatchPending();
}
if (pull.getTimeout() > 0) {
scheduler.executeAfterDelay(new Runnable() {
@Override
public void run() {
pullTimeout(dispatchCounterBeforePull);
}
}, pull.getTimeout());
}
}
}
}
return null;
}
/**
* Occurs when a pull times out. If nothing has been dispatched since the
* timeout was setup, then send the NULL message.
*/
final void pullTimeout(long dispatchCounterBeforePull) {
synchronized (pendingLock) {
if (dispatchCounterBeforePull == dispatchCounter) {
try {
add(QueueMessageReference.NULL_MESSAGE);
dispatchPending();
} catch (Exception e) {
context.getConnection().serviceException(e);
}
}
}
}
@Override
public void add(MessageReference node) throws Exception {
synchronized (pendingLock) {
// The destination may have just been removed...
if( !destinations.contains(node.getRegionDestination()) && node!=QueueMessageReference.NULL_MESSAGE) {
// perhaps we should inform the caller that we are no longer valid to dispatch to?
return;
}
// Don't increment for the pullTimeout control message.
if (!node.equals(QueueMessageReference.NULL_MESSAGE)) {
enqueueCounter++;
}
pending.addMessageLast(node);
}
dispatchPending();
}
@Override
public void processMessageDispatchNotification(MessageDispatchNotification mdn) throws Exception {
synchronized(pendingLock) {
try {
pending.reset();
while (pending.hasNext()) {
MessageReference node = pending.next();
node.decrementReferenceCount();
if (node.getMessageId().equals(mdn.getMessageId())) {
// Synchronize between dispatched list and removal of messages from pending list
// related to remove subscription action
synchronized(dispatchLock) {
pending.remove();
createMessageDispatch(node, node.getMessage());
dispatched.add(node);
onDispatch(node, node.getMessage());
}
return;
}
}
} finally {
pending.release();
}
}
throw new JMSException(
"Slave broker out of sync with master: Dispatched message ("
+ mdn.getMessageId() + ") was not in the pending list for "
+ mdn.getConsumerId() + " on " + mdn.getDestination().getPhysicalName());
}
@Override
public final void acknowledge(final ConnectionContext context,final MessageAck ack) throws Exception {
// Handle the standard acknowledgment case.
boolean callDispatchMatched = false;
Destination destination = null;
if (!okForAckAsDispatchDone.await(0l, TimeUnit.MILLISECONDS)) {
// suppress unexpected ack exception in this expected case
LOG.warn("Ignoring ack received before dispatch; result of failover with an outstanding ack. Acked messages will be replayed if present on this broker. Ignored ack: {}", ack);
return;
}
LOG.trace("ack: {}", ack);
synchronized(dispatchLock) {
if (ack.isStandardAck()) {
// First check if the ack matches the dispatched. When using failover this might
// not be the case. We don't ever want to ack the wrong messages.
assertAckMatchesDispatched(ack);
// Acknowledge all dispatched messages up till the message id of
// the acknowledgment.
int index = 0;
boolean inAckRange = false;
List removeList = new ArrayList();
for (final MessageReference node : dispatched) {
MessageId messageId = node.getMessageId();
if (ack.getFirstMessageId() == null
|| ack.getFirstMessageId().equals(messageId)) {
inAckRange = true;
}
if (inAckRange) {
// Don't remove the nodes until we are committed.
if (!context.isInTransaction()) {
dequeueCounter++;
((Destination)node.getRegionDestination()).getDestinationStatistics().getInflight().decrement();
removeList.add(node);
} else {
registerRemoveSync(context, node);
}
index++;
acknowledge(context, ack, node);
if (ack.getLastMessageId().equals(messageId)) {
destination = (Destination) node.getRegionDestination();
callDispatchMatched = true;
break;
}
}
}
for (final MessageReference node : removeList) {
dispatched.remove(node);
}
// this only happens after a reconnect - get an ack which is not
// valid
if (!callDispatchMatched) {
LOG.warn("Could not correlate acknowledgment with dispatched message: {}", ack);
}
} else if (ack.isIndividualAck()) {
// Message was delivered and acknowledge - but only delete the
// individual message
for (final MessageReference node : dispatched) {
MessageId messageId = node.getMessageId();
if (ack.getLastMessageId().equals(messageId)) {
// Don't remove the nodes until we are committed - immediateAck option
if (!context.isInTransaction()) {
dequeueCounter++;
((Destination)node.getRegionDestination()).getDestinationStatistics().getInflight().decrement();
dispatched.remove(node);
} else {
registerRemoveSync(context, node);
}
if (usePrefetchExtension && getPrefetchSize() != 0 && ack.isInTransaction()) {
// allow transaction batch to exceed prefetch
while (true) {
int currentExtension = prefetchExtension.get();
int newExtension = Math.max(currentExtension, currentExtension + 1);
if (prefetchExtension.compareAndSet(currentExtension, newExtension)) {
break;
}
}
}
acknowledge(context, ack, node);
destination = (Destination) node.getRegionDestination();
callDispatchMatched = true;
break;
}
}
}else if (ack.isDeliveredAck() || ack.isExpiredAck()) {
// Message was delivered but not acknowledged: update pre-fetch
// counters.
int index = 0;
for (Iterator iter = dispatched.iterator(); iter.hasNext(); index++) {
final MessageReference node = iter.next();
Destination nodeDest = (Destination) node.getRegionDestination();
if (node.isExpired()) {
if (broker.isExpired(node)) {
Destination regionDestination = nodeDest;
regionDestination.messageExpired(context, this, node);
}
iter.remove();
nodeDest.getDestinationStatistics().getInflight().decrement();
}
if (ack.getLastMessageId().equals(node.getMessageId())) {
if (usePrefetchExtension && getPrefetchSize() != 0) {
// allow batch to exceed prefetch
while (true) {
int currentExtension = prefetchExtension.get();
int newExtension = Math.max(currentExtension, index + 1);
if (prefetchExtension.compareAndSet(currentExtension, newExtension)) {
break;
}
}
}
destination = nodeDest;
callDispatchMatched = true;
break;
}
}
if (!callDispatchMatched) {
throw new JMSException(
"Could not correlate acknowledgment with dispatched message: "
+ ack);
}
} else if (ack.isRedeliveredAck()) {
// Message was re-delivered but it was not yet considered to be
// a DLQ message.
boolean inAckRange = false;
for (final MessageReference node : dispatched) {
MessageId messageId = node.getMessageId();
if (ack.getFirstMessageId() == null
|| ack.getFirstMessageId().equals(messageId)) {
inAckRange = true;
}
if (inAckRange) {
if (ack.getLastMessageId().equals(messageId)) {
destination = (Destination) node.getRegionDestination();
callDispatchMatched = true;
break;
}
}
}
if (!callDispatchMatched) {
throw new JMSException(
"Could not correlate acknowledgment with dispatched message: "
+ ack);
}
} else if (ack.isPoisonAck()) {
// TODO: what if the message is already in a DLQ???
// Handle the poison ACK case: we need to send the message to a
// DLQ
if (ack.isInTransaction()) {
throw new JMSException("Poison ack cannot be transacted: "
+ ack);
}
int index = 0;
boolean inAckRange = false;
List removeList = new ArrayList();
for (final MessageReference node : dispatched) {
MessageId messageId = node.getMessageId();
if (ack.getFirstMessageId() == null
|| ack.getFirstMessageId().equals(messageId)) {
inAckRange = true;
}
if (inAckRange) {
sendToDLQ(context, node, ack.getPoisonCause());
Destination nodeDest = (Destination) node.getRegionDestination();
nodeDest.getDestinationStatistics()
.getInflight().decrement();
removeList.add(node);
dequeueCounter++;
index++;
acknowledge(context, ack, node);
if (ack.getLastMessageId().equals(messageId)) {
while (true) {
int currentExtension = prefetchExtension.get();
int newExtension = Math.max(0, currentExtension - (index + 1));
if (prefetchExtension.compareAndSet(currentExtension, newExtension)) {
break;
}
}
destination = nodeDest;
callDispatchMatched = true;
break;
}
}
}
for (final MessageReference node : removeList) {
dispatched.remove(node);
}
if (!callDispatchMatched) {
throw new JMSException(
"Could not correlate acknowledgment with dispatched message: "
+ ack);
}
}
}
if (callDispatchMatched && destination != null) {
destination.wakeup();
dispatchPending();
if (pending.isEmpty()) {
for (Destination dest : destinations) {
dest.wakeup();
}
}
} else {
LOG.debug("Acknowledgment out of sync (Normally occurs when failover connection reconnects): {}", ack);
}
}
private void registerRemoveSync(ConnectionContext context, final MessageReference node) {
// setup a Synchronization to remove nodes from the
// dispatched list.
context.getTransaction().addSynchronization(
new Synchronization() {
@Override
public void beforeEnd() {
if (usePrefetchExtension && getPrefetchSize() != 0) {
while (true) {
int currentExtension = prefetchExtension.get();
int newExtension = Math.max(0, currentExtension - 1);
if (prefetchExtension.compareAndSet(currentExtension, newExtension)) {
break;
}
}
}
}
@Override
public void afterCommit()
throws Exception {
Destination nodeDest = (Destination) node.getRegionDestination();
synchronized(dispatchLock) {
dequeueCounter++;
dispatched.remove(node);
nodeDest.getDestinationStatistics().getInflight().decrement();
}
nodeDest.wakeup();
dispatchPending();
}
@Override
public void afterRollback() throws Exception {
synchronized(dispatchLock) {
// poisionAck will decrement - otherwise still inflight on client
}
}
});
}
/**
* Checks an ack versus the contents of the dispatched list.
* called with dispatchLock held
* @param ack
* @throws JMSException if it does not match
*/
protected void assertAckMatchesDispatched(MessageAck ack) throws JMSException {
MessageId firstAckedMsg = ack.getFirstMessageId();
MessageId lastAckedMsg = ack.getLastMessageId();
int checkCount = 0;
boolean checkFoundStart = false;
boolean checkFoundEnd = false;
for (MessageReference node : dispatched) {
if (firstAckedMsg == null) {
checkFoundStart = true;
} else if (!checkFoundStart && firstAckedMsg.equals(node.getMessageId())) {
checkFoundStart = true;
}
if (checkFoundStart) {
checkCount++;
}
if (lastAckedMsg != null && lastAckedMsg.equals(node.getMessageId())) {
checkFoundEnd = true;
break;
}
}
if (!checkFoundStart && firstAckedMsg != null)
throw new JMSException("Unmatched acknowledge: " + ack
+ "; Could not find Message-ID " + firstAckedMsg
+ " in dispatched-list (start of ack)");
if (!checkFoundEnd && lastAckedMsg != null)
throw new JMSException("Unmatched acknowledge: " + ack
+ "; Could not find Message-ID " + lastAckedMsg
+ " in dispatched-list (end of ack)");
if (ack.getMessageCount() != checkCount && !ack.isInTransaction()) {
throw new JMSException("Unmatched acknowledge: " + ack
+ "; Expected message count (" + ack.getMessageCount()
+ ") differs from count in dispatched-list (" + checkCount
+ ")");
}
}
/**
*
* @param context
* @param node
* @param poisonCause
* @throws IOException
* @throws Exception
*/
protected void sendToDLQ(final ConnectionContext context, final MessageReference node, Throwable poisonCause) throws IOException, Exception {
broker.getRoot().sendToDeadLetterQueue(context, node, this, poisonCause);
}
@Override
public int getInFlightSize() {
return dispatched.size();
}
/**
* Used to determine if the broker can dispatch to the consumer.
*
* @return
*/
@Override
public boolean isFull() {
return getPrefetchSize() == 0 ? prefetchExtension.get() == 0 : dispatched.size() - prefetchExtension.get() >= info.getPrefetchSize();
}
/**
* @return true when 60% or more room is left for dispatching messages
*/
@Override
public boolean isLowWaterMark() {
return (dispatched.size() - prefetchExtension.get()) <= (info.getPrefetchSize() * .4);
}
/**
* @return true when 10% or less room is left for dispatching messages
*/
@Override
public boolean isHighWaterMark() {
return (dispatched.size() - prefetchExtension.get()) >= (info.getPrefetchSize() * .9);
}
@Override
public int countBeforeFull() {
return getPrefetchSize() == 0 ? prefetchExtension.get() : info.getPrefetchSize() + prefetchExtension.get() - dispatched.size();
}
@Override
public int getPendingQueueSize() {
return pending.size();
}
@Override
public int getDispatchedQueueSize() {
return dispatched.size();
}
@Override
public long getDequeueCounter() {
return dequeueCounter;
}
@Override
public long getDispatchedCounter() {
return dispatchCounter;
}
@Override
public long getEnqueueCounter() {
return enqueueCounter;
}
@Override
public boolean isRecoveryRequired() {
return pending.isRecoveryRequired();
}
public PendingMessageCursor getPending() {
return this.pending;
}
public void setPending(PendingMessageCursor pending) {
this.pending = pending;
if (this.pending!=null) {
this.pending.setSystemUsage(usageManager);
this.pending.setMemoryUsageHighWaterMark(getCursorMemoryHighWaterMark());
}
}
@Override
public void add(ConnectionContext context, Destination destination) throws Exception {
synchronized(pendingLock) {
super.add(context, destination);
pending.add(context, destination);
}
}
@Override
public List remove(ConnectionContext context, Destination destination) throws Exception {
return remove(context, destination, dispatched);
}
public List remove(ConnectionContext context, Destination destination, List dispatched) throws Exception {
List rc = new ArrayList();
synchronized(pendingLock) {
super.remove(context, destination);
// Here is a potential problem concerning Inflight stat:
// Messages not already committed or rolled back may not be removed from dispatched list at the moment
// Except if each commit or rollback callback action comes before remove of subscriber.
rc.addAll(pending.remove(context, destination));
if (dispatched == null) {
return rc;
}
// Synchronized to DispatchLock if necessary
if (dispatched == this.dispatched) {
synchronized(dispatchLock) {
updateDestinationStats(rc, destination, dispatched);
}
} else {
updateDestinationStats(rc, destination, dispatched);
}
}
return rc;
}
private void updateDestinationStats(List rc, Destination destination, List dispatched) {
ArrayList references = new ArrayList();
for (MessageReference r : dispatched) {
if (r.getRegionDestination() == destination) {
references.add(r);
}
}
rc.addAll(references);
destination.getDestinationStatistics().getInflight().subtract(references.size());
dispatched.removeAll(references);
}
// made public so it can be used in MQTTProtocolConverter
public void dispatchPending() throws IOException {
synchronized(pendingLock) {
try {
int numberToDispatch = countBeforeFull();
if (numberToDispatch > 0) {
setSlowConsumer(false);
setPendingBatchSize(pending, numberToDispatch);
int count = 0;
pending.reset();
while (pending.hasNext() && !isFull() && count < numberToDispatch) {
MessageReference node = pending.next();
if (node == null) {
break;
}
// Synchronize between dispatched list and remove of message from pending list
// related to remove subscription action
synchronized(dispatchLock) {
pending.remove();
node.decrementReferenceCount();
if( !isDropped(node) && canDispatch(node)) {
// Message may have been sitting in the pending
// list a while waiting for the consumer to ak the message.
if (node!=QueueMessageReference.NULL_MESSAGE && node.isExpired()) {
//increment number to dispatch
numberToDispatch++;
if (broker.isExpired(node)) {
((Destination)node.getRegionDestination()).messageExpired(context, this, node);
}
continue;
}
dispatch(node);
count++;
}
}
}
} else if (!isSlowConsumer()) {
setSlowConsumer(true);
for (Destination dest :destinations) {
dest.slowConsumer(context, this);
}
}
} finally {
pending.release();
}
}
}
protected void setPendingBatchSize(PendingMessageCursor pending, int numberToDispatch) {
pending.setMaxBatchSize(numberToDispatch);
}
// called with dispatchLock held
protected boolean dispatch(final MessageReference node) throws IOException {
final Message message = node.getMessage();
if (message == null) {
return false;
}
okForAckAsDispatchDone.countDown();
MessageDispatch md = createMessageDispatch(node, message);
if (node != QueueMessageReference.NULL_MESSAGE) {
dispatchCounter++;
dispatched.add(node);
}
if (getPrefetchSize() == 0) {
while (true) {
int currentExtension = prefetchExtension.get();
int newExtension = Math.max(0, currentExtension - 1);
if (prefetchExtension.compareAndSet(currentExtension, newExtension)) {
break;
}
}
}
if (info.isDispatchAsync()) {
md.setTransmitCallback(new TransmitCallback() {
@Override
public void onSuccess() {
// Since the message gets queued up in async dispatch, we don't want to
// decrease the reference count until it gets put on the wire.
onDispatch(node, message);
}
@Override
public void onFailure() {
Destination nodeDest = (Destination) node.getRegionDestination();
if (nodeDest != null) {
if (node != QueueMessageReference.NULL_MESSAGE) {
nodeDest.getDestinationStatistics().getDispatched().increment();
nodeDest.getDestinationStatistics().getInflight().increment();
LOG.trace("{} failed to dispatch: {} - {}, dispatched: {}, inflight: {}", new Object[]{ info.getConsumerId(), message.getMessageId(), message.getDestination(), dispatchCounter, dispatched.size() });
}
}
if (node instanceof QueueMessageReference) {
((QueueMessageReference) node).unlock();
}
}
});
context.getConnection().dispatchAsync(md);
} else {
context.getConnection().dispatchSync(md);
onDispatch(node, message);
}
return true;
}
protected void onDispatch(final MessageReference node, final Message message) {
Destination nodeDest = (Destination) node.getRegionDestination();
if (nodeDest != null) {
if (node != QueueMessageReference.NULL_MESSAGE) {
nodeDest.getDestinationStatistics().getDispatched().increment();
nodeDest.getDestinationStatistics().getInflight().increment();
LOG.trace("{} dispatched: {} - {}, dispatched: {}, inflight: {}", new Object[]{ info.getConsumerId(), message.getMessageId(), message.getDestination(), dispatchCounter, dispatched.size() });
}
}
if (info.isDispatchAsync()) {
try {
dispatchPending();
} catch (IOException e) {
context.getConnection().serviceExceptionAsync(e);
}
}
}
/**
* inform the MessageConsumer on the client to change it's prefetch
*
* @param newPrefetch
*/
@Override
public void updateConsumerPrefetch(int newPrefetch) {
if (context != null && context.getConnection() != null && context.getConnection().isManageable()) {
ConsumerControl cc = new ConsumerControl();
cc.setConsumerId(info.getConsumerId());
cc.setPrefetch(newPrefetch);
context.getConnection().dispatchAsync(cc);
}
}
/**
* @param node
* @param message
* @return MessageDispatch
*/
protected MessageDispatch createMessageDispatch(MessageReference node, Message message) {
MessageDispatch md = new MessageDispatch();
md.setConsumerId(info.getConsumerId());
if (node == QueueMessageReference.NULL_MESSAGE) {
md.setMessage(null);
md.setDestination(null);
} else {
Destination regionDestination = (Destination) node.getRegionDestination();
md.setDestination(regionDestination.getActiveMQDestination());
md.setMessage(message);
md.setRedeliveryCounter(node.getRedeliveryCounter());
}
return md;
}
/**
* Use when a matched message is about to be dispatched to the client.
*
* @param node
* @return false if the message should not be dispatched to the client
* (another sub may have already dispatched it for example).
* @throws IOException
*/
protected abstract boolean canDispatch(MessageReference node) throws IOException;
protected abstract boolean isDropped(MessageReference node);
/**
* Used during acknowledgment to remove the message.
*
* @throws IOException
*/
protected abstract void acknowledge(ConnectionContext context, final MessageAck ack, final MessageReference node) throws IOException;
public int getMaxProducersToAudit() {
return maxProducersToAudit;
}
public void setMaxProducersToAudit(int maxProducersToAudit) {
this.maxProducersToAudit = maxProducersToAudit;
if (this.pending != null) {
this.pending.setMaxProducersToAudit(maxProducersToAudit);
}
}
public int getMaxAuditDepth() {
return maxAuditDepth;
}
public void setMaxAuditDepth(int maxAuditDepth) {
this.maxAuditDepth = maxAuditDepth;
if (this.pending != null) {
this.pending.setMaxAuditDepth(maxAuditDepth);
}
}
public boolean isUsePrefetchExtension() {
return usePrefetchExtension;
}
public void setUsePrefetchExtension(boolean usePrefetchExtension) {
this.usePrefetchExtension = usePrefetchExtension;
}
protected int getPrefetchExtension() {
return this.prefetchExtension.get();
}
@Override
public void setPrefetchSize(int prefetchSize) {
this.info.setPrefetchSize(prefetchSize);
try {
this.dispatchPending();
} catch (Exception e) {
LOG.trace("Caught exception during dispatch after prefetch change.", e);
}
}
}