rabbitmq-consumers verifiedimportantWritten by the Hub
Consumer threads
in the configuration this is a line
rabbitmq-consumers: 10How many threads read from the consumed queue in parallel.
Values
- Values
positive integer- Default
10 · taken from the build- applying
restart required- where it can be set
in the config file · with a startup flag · as an environment variable
In detail
Each thread holds its own prefetch window, so the number of messages a node keeps in flight is this value multiplied by rabbitmq-qos. On the stand the queue shows exactly ten consumers, which matches the shipped value — and contradicts the documentation, which states a default of one. Raising it costs memory and broker connections; lowering it below the number of cores rarely helps anything.
What happens if you get it wrong
Left at the shipped ten on a small node.Prefetch multiplies. Measured on mq-01: ten consumers, window 1000 each — up to 10 000 messages claimed at once. On the 2 GB node we were given that is already the dominant memory consumer before a single message is sent.verified by experiment · inference