Queue

The retained stream, group position and PEL change separately. Delivery advances the position before ACK; ACK removes pending references. XAUTOCLAIM moves ownership, can repeat modeled effects, and cannot recover a deleted payload. Historical source illustration.

Redis Streams let a group share the work

A Redis Streams consumer group distributes new entries among named consumers and records deliveries awaiting acknowledgement. It does not guarantee exactly-once effects, prevent retention loss, or recover abandoned work by itself. Understanding the group position, pending entries, and retained stream data separately is essential before treating it as a work queue. ...

Two a,b,c rows compare RPUSH with LPOP at the opposite end for FIFO and RPOP at the same end for LIFO.

A Redis list is a queue, a stack, or both

A Redis list is an ordered sequence of byte values with operations at both ends. Choosing the push and pop ends determines whether it behaves as a queue or a stack. Blocking operations wait for data; they are not distributed locks, acknowledgements, or a complete message-processing protocol. ...