@Override
public List<Message> peekMessagesByKey(String key) throws MessageQueueException {
String groupRowKey = getCompositeKey(getName(), key);
List<Message> messages = Lists.newArrayList();
try {
ColumnList<MessageMetadataEntry> columns =
keyspace
.prepareQuery(keyIndexColumnFamily)
.getRow(groupRowKey)
.withColumnRange(
metadataSerializer
.buildRange()
.greaterThanEquals((byte) MessageMetadataEntryType.MessageId.ordinal())
.lessThanEquals((byte) MessageMetadataEntryType.MessageId.ordinal())
.build())
.execute()
.getResult();
for (Column<MessageMetadataEntry> entry : columns) {
if (entry.getTtl() != 0) continue;
Message message = peekMessage(entry.getName().getName());
if (message != null) {
messages.add(peekMessage(entry.getName().getName()));
} else {
LOG.warn("No queue item for " + entry.getName());
}
}
} catch (NotFoundException e) {
} catch (ConnectionException e) {
throw new MessageQueueException("Error fetching row " + groupRowKey, e);
}
return messages;
}
@Override
public Message peekMessageByKey(String key) throws MessageQueueException {
String groupRowKey = getCompositeKey(getName(), key);
try {
ColumnList<MessageMetadataEntry> columns =
keyspace
.prepareQuery(keyIndexColumnFamily)
.setConsistencyLevel(consistencyLevel)
.getRow(groupRowKey)
.withColumnRange(
metadataSerializer
.buildRange()
.greaterThanEquals((byte) MessageMetadataEntryType.MessageId.ordinal())
.lessThanEquals((byte) MessageMetadataEntryType.MessageId.ordinal())
.build())
.execute()
.getResult();
for (Column<MessageMetadataEntry> entry : columns) {
if (entry.getTtl() != 0) continue;
// Return the first one we get. Hmmm... maybe we want to do some validation checks here
return peekMessage(entry.getName().getName());
}
return null;
} catch (NotFoundException e) {
return null;
} catch (ConnectionException e) {
throw new MessageQueueException("Error fetching row " + groupRowKey, e);
}
}
/**
* Read the data stored with the unique row. This data is normally a 'foreign' key to another
* column family.
*
* @return
* @throws Exception
*/
public ByteBuffer readData() throws Exception {
ColumnList<C> result =
keyspace
.prepareQuery(columnFamily)
.setConsistencyLevel(consistencyLevel)
.getKey(key)
.execute()
.getResult();
boolean hasColumn = false;
ByteBuffer data = null;
for (Column<C> column : result) {
if (column.getTtl() == 0) {
if (hasColumn) {
throw new IllegalStateException("Row has multiple uniquneness locks");
}
hasColumn = true;
data = column.getByteBufferValue();
}
}
if (!hasColumn) {
throw new NotFoundException(this.key.toString() + " has no uniquness lock");
}
return data;
}
private List<MessageContext> readMessagesInternal(
String shardName,
int itemsToPop,
int lockColumnCount,
MessageQueueEntry lockColumn,
ColumnListMutation<MessageQueueEntry> rowMutation,
MutationBatch m,
long curTimeMicros)
throws BusyLockException, MessageQueueException {
try {
List<MessageContext> entries = Lists.newArrayList();
RangeEndpoint re =
ShardedDistributedMessageQueue.entrySerializer
.makeEndpoint((byte) MessageQueueEntryType.Message.ordinal(), Equality.EQUAL)
.append((byte) 0, Equality.EQUAL);
if (lockColumn != null) {
re.append(lockColumn.getTimestamp(), Equality.LESS_THAN_EQUALS);
} else {
re.append(TimeUUIDUtils.getMicrosTimeUUID(curTimeMicros), Equality.LESS_THAN_EQUALS);
}
ColumnList<MessageQueueEntry> result =
queue
.keyspace
.prepareQuery(queue.queueColumnFamily)
.setConsistencyLevel(queue.consistencyLevel)
.getKey(shardName)
.withColumnRange(
new RangeBuilder()
.setLimit(itemsToPop + (lockColumn == null ? 0 : (lockColumnCount + 1)))
.setEnd(re.toBytes())
.build())
.execute()
.getResult();
for (Column<MessageQueueEntry> column : result) {
if (itemsToPop == 0) {
break;
}
MessageQueueEntry entry = column.getName();
switch (entry.getType()) {
case Lock:
// TODO: Track number of locks read and make sure we don't exceed itemsToPop
// We have the lock
if (lockColumn != null && entry.getState() == MessageQueueEntryState.Acquired) {
if (!entry.getTimestamp().equals(lockColumn.getTimestamp())) {
throw new BusyLockException("Someone else snuck in");
}
}
break;
case Message:
{
try {
itemsToPop--;
// First, we always want to remove the old item
String messageId = queue.getCompositeKey(shardName, entry.getMessageId());
rowMutation.deleteColumn(entry);
// Next, parse the message metadata and add a timeout entry
final Message message = queue.extractMessageFromColumn(column);
// Update the message state
if (message != null) {
MessageContext context = new MessageContext();
context.setMessage(message);
// Message has a trigger so we need to figure out if it is an
// unfinished repeating trigger and re-add it.
if (message.hasTrigger()) {
// Read back all messageIds associated with this key and check to see if we have
// duplicates.
String groupRowKey = queue.getCompositeKey(queue.getName(), message.getKey());
try {
// Use consistency level
ColumnList<MessageMetadataEntry> columns =
queue
.keyspace
.prepareQuery(queue.keyIndexColumnFamily)
.getRow(groupRowKey)
.withColumnRange(
ShardedDistributedMessageQueue.metadataSerializer
.buildRange()
.greaterThanEquals(
(byte) MessageMetadataEntryType.MessageId.ordinal())
.lessThanEquals(
(byte) MessageMetadataEntryType.MessageId.ordinal())
.build())
.execute()
.getResult();
MessageMetadataEntry mostRecentMessageMetadata = null;
long mostRecentTriggerTime = 0;
for (Column<MessageMetadataEntry> currMessageEntry : columns) {
MessageQueueEntry pendingMessageEntry =
MessageQueueEntry.fromMetadata(currMessageEntry.getName());
if (currMessageEntry.getTtl() == 0) {
long currMessageTriggerTime =
pendingMessageEntry.getTimestamp(TimeUnit.MICROSECONDS);
// First message we found, so treat as the most recent
if (mostRecentMessageMetadata == null) {
mostRecentMessageMetadata = currMessageEntry.getName();
mostRecentTriggerTime = currMessageTriggerTime;
} else {
// This message's trigger time is after what we thought was the most
// recent.
// Discard the previous 'most' recent and accept this one instead
if (currMessageTriggerTime > mostRecentTriggerTime) {
LOG.warn(
"Need to discard : "
+ entry.getMessageId()
+ " => "
+ mostRecentMessageMetadata.getName());
m.withRow(
queue.keyIndexColumnFamily,
queue.getCompositeKey(queue.getName(), message.getKey()))
.putEmptyColumn(
mostRecentMessageMetadata, queue.metadataDeleteTTL);
mostRecentTriggerTime = currMessageTriggerTime;
mostRecentMessageMetadata = currMessageEntry.getName();
} else {
LOG.warn(
"Need to discard : "
+ entry.getMessageId()
+ " => "
+ currMessageEntry.getName());
m.withRow(
queue.keyIndexColumnFamily,
queue.getCompositeKey(queue.getName(), message.getKey()))
.putEmptyColumn(
currMessageEntry.getName(), queue.metadataDeleteTTL);
}
}
}
}
if (mostRecentMessageMetadata != null) {
if (!mostRecentMessageMetadata.getName().endsWith(entry.getMessageId())) {
throw new DuplicateMessageException("Duplicate trigger for " + messageId);
}
}
} catch (NotFoundException e) {
} catch (ConnectionException e) {
throw new MessageQueueException("Error fetching row " + groupRowKey, e);
}
// Update the trigger
final Message nextMessage;
Trigger trigger = message.getTrigger().nextTrigger();
if (trigger != null) {
nextMessage = message.clone();
nextMessage.setTrigger(trigger);
context.setNextMessage(nextMessage);
if (message.isAutoCommitTrigger()) {
queue.fillMessageMutation(m, nextMessage);
}
}
}
// Message has a key so we remove this item from the messages by key index.
// A timeout item will be added later
if (message.hasKey()) {
m.withRow(
queue.keyIndexColumnFamily,
queue.getCompositeKey(queue.getName(), message.getKey()))
.putEmptyColumn(
MessageMetadataEntry.newMessageId(messageId), queue.metadataDeleteTTL);
LOG.debug(
"Removing from key : "
+ queue.getCompositeKey(queue.getName(), message.getKey())
+ " : "
+ messageId);
if (message.isKeepHistory()) {
MessageHistory history = context.getHistory();
history.setToken(entry.getTimestamp());
history.setStartTime(curTimeMicros);
history.setTriggerTime(message.getTrigger().getTriggerTime());
history.setStatus(MessageStatus.RUNNING);
try {
m.withRow(queue.historyColumnFamily, message.getKey())
.putColumn(
entry.getTimestamp(),
queue.serializeToString(history),
queue.metadata.getHistoryTtl());
} catch (Exception e) {
LOG.warn("Error serializing history for key '" + message.getKey() + "'", e);
}
}
}
// Message has a timeout so we add a timeout event.
if (message.getTimeout() > 0) {
MessageQueueEntry timeoutEntry =
MessageQueueEntry.newMessageEntry(
(byte) 0,
TimeUUIDUtils.getMicrosTimeUUID(
curTimeMicros
+ TimeUnit.MICROSECONDS.convert(
message.getTimeout(), TimeUnit.SECONDS)
+ (queue.counter.incrementAndGet() % 1000)),
MessageQueueEntryState.Busy);
message.setToken(timeoutEntry.getTimestamp());
message.setRandom(timeoutEntry.getRandom());
m.withRow(queue.queueColumnFamily, queue.getShardKey(message))
.putColumn(
timeoutEntry,
column.getStringValue(),
queue.metadata.getRetentionTimeout());
MessageMetadataEntry messageIdEntry =
MessageMetadataEntry.newMessageId(
queue.getCompositeKey(
queue.getShardKey(message), timeoutEntry.getMessageId()));
// Add the timeout column to the key
if (message.hasKey()) {
m.withRow(
queue.keyIndexColumnFamily,
queue.getCompositeKey(queue.getName(), message.getKey()))
.putEmptyColumn(messageIdEntry, queue.metadata.getRetentionTimeout());
}
context.setAckMessageId(messageIdEntry.getName());
} else {
message.setToken(null);
}
// Update some stats
switch (entry.getState()) {
case Waiting:
queue.stats.incProcessCount();
break;
case Busy:
queue.stats.incReprocessCount();
break;
default:
LOG.warn("Unknown message state: " + entry.getState());
// TODO:
break;
}
entries.add(context);
} else {
queue.stats.incInvalidMessageCount();
// TODO: Add to poison queue
}
} catch (DuplicateMessageException e) {
// OK to ignore this error. All the proper columns will have been deleted in the
// batch.
}
break;
}
default:
{
// TODO: Error: Unknown type
break;
}
}
}
return entries;
} catch (BusyLockException e) {
queue.stats.incLockContentionCount();
throw e;
} catch (Exception e) {
throw new MessageQueueException("Error processing queue shard : " + shardName, e);
} finally {
try {
m.execute();
} catch (Exception e) {
throw new MessageQueueException("Error processing queue shard : " + shardName, e);
}
}
}