I have yet to dig deeper, but the fact that it uses Thrift and already has worker implementations in C++ and Java is a huge plus. Celery is a Python lock-in and makes it non-trivial to split your enqueue code and worker code. Celery on the other hand, since it is Python all the way down, let’s you orchestrate the execution of dependant tasks. In my experience these features contribute to a more complex codebase that is harder to maintain, test and understand.

Celery has flexibility for message backends, but prefers RabbitMQ which comes with its own operations overhead, and does not have real horizontal scaling built in (it has failover techniques). RabbitMQ is great for mission critical messaging that survive system restarts.

My biggest worry is relying on Redis or MySQL. What happens if workers stop consuming tasks, wouldn’t that balloon the redis memory consumption pretty quickly? I suppose memory consumption is a factor of load and task bytesize. MySQL on the other hand feels like the wrong tool for this job.