Message order issue in single consumer connected to ActiveMQ Artemis queue

Question

Any possibility of message order issue while receive single queue consumer and multiple producer? producer1 publish message m1 at 2021-06-27 02:57:44.513 and producer2 publish message m2 at 2021-06-27 02:57:44.514 on same queue worker_consumer_queue. Client code connected to the queue configured as single consumer should receive message in order m1 first and then m2 correct? Sometimes message receive in wrong order. version is ActiveMQ Artemis 2.17.0. Even though I mentioned that multiple producer, message publish one after another from same thread using property blockOnDurableSend=false.

I create and close producer on each message publish. On same JVM, my assumption is order of published messages in queue, from same thread or from different threads even with async. timestamp is getJMSTimestamp(). async publish also maintain any internal queue has order?

Answer 1

If you use blockOnDurableSend=false you're basically saying you don't strictly care about the order or even if the message makes it to the broker at all. Using blockOnDurableSend=false basically means "fire and forget."

Furthermore, the JMSTimetamp is not when the message is actually sent as noted in the javax.jms.Message JavaDoc:

The JMSTimestamp header field contains the time a message was handed off to a provider to be sent. It is not the time the message was actually transmitted, because the actual send may occur later due to transactions or other client-side queueing of messages.

Answer 2

With more than one producer there is no guarantee that the messages will be processed in order.

Answer 3

More producers, ActiveMQ Artemis and one consumer are a distributed system and the lack of a global clock is a significant characteristic of distributed systems.

Even if producers and ActiveMQ Artemis were on the same machine and used the same clock, ActiveMQ Artemis could not receive the messages in the same order producers would create and send their messages. Because the time to create a message and the time to send a message include variable time latencies.

The easiest solution is to trust the order of the messages received by ActiveMQ Artemis, adding a timestamp with an interceptor or enabling the ingress timestamp, see ARTEMIS-2919 for further details.

If the easiest solution doesn't work, the distributed solution is to implement a distributed system total ordering algorithm as lamport timestamps.

Answer 4

Well, as it seams it is not a bug within Artemis, when it comes to a millisecond difference it is more like a network lag or something like this.

So to workaround I got to the idea, you could create a algorythm in which a recieved message will wait for ~100ms before it is really worked through (whatever you want to be doing with this message) and check if there is another message which your application recieved afterwards but is send before. So basicly have your own receiver queue with a delay.

IF there is message that was before, you could simply move that up in your personal algorythm. You could also think about to reject the first message back to your bus, depending on your settings on queues and topics it would be able to recieve it afterwards again.