Exam AZ-303 topic 1 question 35 discussion

Answer should be "Client2 will read three messages in the following order: M3, M2 and then M1" ? Anyone offer anything different?

It seems none of the answer is correct as the second M3 message is discarded.

Client2 will read three messages in the following order: M3, M2 and then M1"

Messages are sent every second. Client 2 is trying to process the message at 5th second. So there is no way, duplication detection should have kicked in by then.

It should be M3, M2, M1 as duplicate detection is enabled, and the duplication detection window is set to 10 minutes. The second M3 message in the queue would be discarded.

The duplicate detection will look at MessageId property of the brokered message and not the message so all 4 will appear for consumer.

explanation given is correct . i guess it is typo in option D..

https://docs.microsoft.com/en-us/azure/service-bus-messaging/duplicate-detection#duplicate-detection-window-size Since duplicate windows size has by default a minumum size of 20 sec, by default any duplicate message during this period is automatically deleted, and since Queue is FIFO, the correct answer is M3 M2 M1 only.

https://docs.microsoft.com/en-us/azure/service-bus-messaging/duplicate-detection From docs: "If any new message is sent with MessageId that was logged during the time window, the message is reported as accepted (the send operation succeeds), but the newly sent message is instantly ignored and dropped." Pay attention here "the SEND operation succeeds". Meaning you can successfully put duplicates on the bus but they will be discarded. Now question is how Client2 (who READS) will see messages? Hence messages are Dropped immediately after SEND, the client won't read the duplicate. Answer is M3,M2,M1 which is obviously missing. Its an error on examtopics.

Please stop inspecting the message contents when trying to argue the solution. You don't make sense at all. Its not about message ID its about how de-dupe and its window works. The correct answer is missing. Which should be M3, M2, M1. Write an azure function triggered by a Service bus and see yourself.

Correct Answer is D and the reason is M3, M2, M1 & M3 are actual messages(as per the wordings in the question) and doesnt represent Message Id which is what is required for duplicate detection. Since they are actual messages, they will be presented in M3, M2, M1 and M3.

Correct answer is "four messages: M3, M2, M1, M3". Duplication detection does not consider the message content, only MessageID.

Given answer and explanation is correct but option is wrong Still, I'd just take the best option and go for D

Depends on how you understand the question. Let's treat M1, 2 and 3 as message IDs in common sense. None of options is correct. It should be M3, M2 and M1. For dedup, the message is reported as accepted (the send operation succeeds), but the newly sent message is instantly ignored and dropped. So this means to Sender, 2 M3 messages are sent successfully, but for Receiver CLient2, the 2nd M3 is dropped, which means NOT presented to Client2

question is --> How will the messages be presented to Client2? and not what happened to those msgs - so D is correct answer based on the sequence of reading.

From explanation: "It should be M3, M2, M1 as duplicate detection is enabled, and the duplication detection window is set to 10 minutes. The second M3 message in the queue would be discarded." The Clent2 reads the message @M3, M2, M1, M3. But the last M3 will be discarded

This is correct. FIFO - 4 messages will be received by queue but the 2nd M3 will be discarded and won't be processed. Duplicate detection is set to 10 mins, any same message sent within that interval will get discarded.