Spring Message Listener Container doc says:
The durable subscription name needs to be unique within this client's JMS client id. Default is the class name of the specified message listener. Note: Only 1 concurrent consumer (which is the default of this message listener container) is allowed for each durable subscription.
I thought, we can handle concurrent messages at the same time. Am I missing something?
Yes, the documentation is correct. At any point of time there can be only one consumer receiving messages for a durable subscription. All durable subscriptions are identified by a unique id. If one consumer is already receiving messages using an id, another attempt create a consumer with the same id for that durable subscription will fail.
I've had this problem before and our log was full of warnings complain about client id is already in use.
Virtual Topic is an option for ActiveMQ: the idea is similar to what @brainOverflow described, it's a combination of topic and queues. The producer sends the message to a topic which is subscribed by queues and each queue receives a copy of the message.
