a simple blocking example

blockingExample.json

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This pattern demonstrates blocking behaviour and the idea of backpressure.

It has two paths - the top emits messages at 1 message per second and the bottom emits messages at 1 message every 2 seconds. The messages are set to keys and merged, before being printed. This pattern emits 1 message every 2 seconds, as the merge operation has to wait for the slower path to satisfy before releasing the pressure on the top path.