Update streams.md with XREADGROUP behavior details (#2553)

* Update streams.md with XREADGROUP behavior details

Clarify the behavior of XREADGROUP in Active-Active streams, including message order guarantees and acknowledgment handling.

* Clarify XREADGROUP message order guarantees

Clarified the guarantee of message order in XREADGROUP regarding consumed messages from multiple regions.

* Update XREADGROUP message ordering explanation

Clarified the message ordering guarantee for XREADGROUP in multi-region scenarios.

* Update order guarantees for Active-Active streams

Clarified the guarantees of entry order for multiple regions in Active-Active streams.

* Apply suggestions from code review

Editorial changes.

---------

Co-authored-by: David Dougherty <[email protected]>

Author: LiorKogan

content/operate/rs/databases/active-active/develop/data-types/streams.md

@@ -297,8 +297,12 @@ This means that the XREADGROUP does not return already-acknowledged entries.
 ### Guarantees
 
 Unlike XREAD, XREADGOUP will never skip stream entries.
+
 In traffic redirection, XREADGROUP may return entries that have been read but not acknowledged. It may also even return entries that have already been acknowledged.
 
+When entries are added from multiple regions, Redis guarantees ordered entries in the reply of a single read command (`XREAD`, `XREADGROUP`, or `XRANGE`). However, ordered IDs are not guaranteed for a sequence of read commands.
+For example, two subsequent `XREADGROUP GROUP group consumer COUNT 1 STREAMS key >` commands may reply with decreasing IDs.
+
 ## Summary
 
 With Active-Active streams, you can write to the same logical stream from multiple regions. As a result, the behavior of Active-Active streams differs somewhat from the behavior you get with Redis Open Source. This is summarized below: