Consumer

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. ...

Billing and analytics point to different positions in one stream, while pending entries remain a separate state from either cursor.

Redis stream groups track delivery positions

A Redis stream does not automatically track a separate cursor for every connection. Ordinary XREAD uses a position supplied by the application. A consumer group instead owns a server-side last-delivered position plus pending delivery records. Confusing those two forms of progress can make a restart skip unfinished work or replay effects already completed. ...