Ankur Mhatre
e1f8aa7402
Kafka, RabbitMQ and Pulsar measured side by side on ordering, replay and consumer scaling by driving the three client libraries directly, plus an operational-footprint measurement of each broker's own distribution. Nine tests, three brokers started without Docker, and every number in the documentation regenerated by scripts/run-all.sh.
19 lines
818 B
Plaintext
19 lines
818 B
Plaintext
== RabbitMQ: FIFO per queue, per consumer ==
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one queue, one consumer, 12 messages
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completion order : [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
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one queue, two consumers, prefetch 1, consumer-1 slower than consumer-2
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completion order : [2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 1, 12]
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out-of-order steps: 1
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A queue is FIFO and a single consumer sees it that way. The moment a second
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consumer is added the broker hands the next message to whichever consumer
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is free, so the order in which work finishes is no longer the order in
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which it was published. There is no key: RabbitMQ has no notion of a
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partition to which related messages could be pinned. Ordering across
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related messages means one queue and one consumer, and therefore no
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horizontal scaling for that queue -- or a consistent-hash exchange, which
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is a plugin.
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