Hello,
Basically Redis has primitives in order to create a dead letter
feature, but the fact it is available or not depends on the library
implementing queues that you are using.
Libraries based on BRPOPLPUSH command or that in general do not remove
the job from the queue before acknowledged processing may have such
feature (sometimes queue systems on top of Redis are basically
implemented in Lua and do many funny things to create new features).
In the case of the new Stream data type of Redis 5, the consumer
groups have explicit dead letter features, you can grep the Redis
streams intro (
https://redis.io/topics/streams-intro) for dead letter,
but it's better that you read it all if you plan to use streams.
Cheers,
Salvatore
--
Salvatore 'antirez' Sanfilippo
open source developer - Redis Labs
https://redislabs.com
"If a system is to have conceptual integrity, someone must control the
concepts."
— Fred Brooks, "The Mythical Man-Month", 1975.