Message Sequencing POC:
In most of the corporate production environments, messages are not sent and received from the same broker. Message might end up from multiple hops and clusters within infrastructure before it actually hits the business consumer. I did a small analysis with ActiveMQ out of the box configuration to use sequencing. Below are the results.
Test Case 1:
Messages are sent to queue / Topic and received in same broker (even from Virtual Destination queue). Single producer and exclusive consumer are used.
Result:
1. Messages are always received in Sequence in normal running consumer
2. Message maintains their sequence even if consumer thread restarts in between
3. Message Priority is IGNORED and sequenced is maintained
4. Results matches the documentation provided here: http://activemq.apache.org/exclusive-consumer.html
Test Case 2:
Messages are going through multiple hops before get consumed from exclusive consumer.
Result:
1. Message loses sequence
2. Priority Set on the messages resets to default (‘4’) regardless of producing value.
Summary:
· If producer and consumer maintained in same broker and consumers are made exclusive; message sequencing is guaranteed.
· If message is making multiple hops before reaching to consumer, sequencing is NOT guaranteed even if Exclusive consumers are used.
In Part II, we will use JMXGroupId concept for message sequencing and find the right results.
