java - How activemq wildcard consumers work? -

i using activemq 5.8 wildcard consumers configured in camel route.

i using default activemq configuration, have defaults below

prefetch = 1 dispatch policy= round robin

now start consumer jvm 5 consumers each 2 queues. both queue has same type of message , same number of messages.

consumers doing nothing printing message (so no db blocking or slow consumer issue)

edit have set prefetch 1 each of queue

what observe 1 of queue getting drained faster other.

what expect both queue getting drained @ equal pace, kind of load balance.

one surprising observation though activemq webconsole shows 5 consumers each of queues

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when debug consumer, see 5 threads / consumers camel flow wildcard queue *.processqueue enter image description here

what cause of above behavior? how make sure queue drain @ equal pace?

did has experience share on writting custom dispatch policy or overriding defaults of activemq?

i able find reference behavior

message distribution in case of wildcard queue consumers random.

though can tuned setting appropriate prefetch size.

after trial & error, arrived @ following formula, have fair distribution across consumers , queue getting de-queued @ same pace.

prefetch = number of wildcard consumers

O9