codelipenghui commented on a change in pull request #2400: PIP-22: Dead Letter Topic URL: https://github.com/apache/incubator-pulsar/pull/2400#discussion_r211807555
########## File path: pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentDispatcherMultipleConsumers.java ########## @@ -556,13 +618,90 @@ public synchronized void redeliverUnacknowledgedMessages(Consumer consumer) { @Override public synchronized void redeliverUnacknowledgedMessages(Consumer consumer, List<PositionImpl> positions) { - positions.forEach(position -> messagesToReplay.add(position.getLedgerId(), position.getEntryId())); if (log.isDebugEnabled()) { log.debug("[{}-{}] Redelivering unacknowledged messages for consumer {}", name, consumer, positions); } + if (maxRedeliveryCount > 0 && redeliveryTracker != null) { + for (PositionImpl position : positions) { + if (redeliveryTracker.incrementAndGetRedeliveryCount(position) <= maxRedeliveryCount) { + messagesToReplay.add(position.getLedgerId(), position.getEntryId()); + } else { + messagesToDeadLetter.add(position); + } + } + if (messagesToDeadLetter.size() > 0) { + CountDownLatch latch = new CountDownLatch(messagesToDeadLetter.size()); + for (PositionImpl position : messagesToDeadLetter) { + cursor.asyncReadEntry(position, new AsyncCallbacks.ReadEntryCallback() { + @Override + public void readEntryComplete(Entry entry, Object ctx) { + if (entry == null) { + log.error("[{}-{}] Read an null entry from cursor {}", name, consumer, position); + latch.countDown(); + } else { + try { + ByteBuf headersAndPayload = entry.getDataBuffer(); + MessageImpl<byte[]> msg = MessageImpl.deserialize(headersAndPayload); + headersAndPayload.retain(); + msg.setReplicatedFrom("DLQ"); + CompletableFuture<MessageId> future = deadLetterTopicProducer.sendAsync(msg); + future.whenCompleteAsync((messageId, error) -> { + if (error != null) { + log.error("[{}-{}] Fail to send message to dead letter topic {} {} {}", + name, consumer, deadLetterTopic, error.getMessage(), error); + messagesToReplay.add(position.getLedgerId(), position.getEntryId()); + latch.countDown(); + } else { + cursor.asyncDelete(position, deleteCallback, position); + redeliveryTracker.remove(position); + latch.countDown(); + } + }); + } catch (Throwable t) { + log.error("[{}-{}] Failed to deserialize message at {} {} {} {}", name, consumer, + entry.getPosition(), entry.getLedgerId(), t.getMessage(), t); + cursor.asyncDelete(position, deleteCallback, position); + redeliveryTracker.remove(position); + entry.release(); + latch.countDown(); + } + } + } + @Override + public void readEntryFailed(ManagedLedgerException exception, Object ctx) { + log.error("[{}-{}] Read entries failed {} {}", name, consumer, exception.getMessage(), exception); + messagesToReplay.add(position.getLedgerId(), position.getEntryId()); + latch.countDown(); + } + }, null); + } + try { Review comment: Oh, I thought that if the last redeliverUnacknowledgedMessages is return but callbacks not complete yet, then another redeliverUnacknowledgedMessages is coming, if last messagesToReplay is not delete yet, so that current messagesToReplay has the last messagesToReplay items. And, I thought that call readMoreEntries() should wait for callbacks complete. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services