sys.fn_hadr_backup_is_preferred_replica() are taking much longer than expected since the patch

Question

sys.fn_hadr_backup_is_preferred_replica() are taking much longer than expected since the patch

Jagadeesh Vadivel 0

We’ve noticed that SQL transaction log backups have become significantly slower following the recent SQL Server 2022 patching.

The issue appears to be affecting multiple Availability Groups rather than a single database. For example, even checks such as sys.fn_hadr_backup_is_preferred_replica() are taking much longer than expected since the patch.

Could you please check whether there are any known issues with the recent SQL Server 2022 CU/patch that could affect log backup performance, AG communication, or backup replica checks?

We’re also reviewing the SQL/AG side to rule out any infrastructure or storage-related delays.

Erland Sommarskog 137.6K Reputation points MVP Volunteer Moderator

2026-09-25T20:30:58.5433333+00:00

Just to set your expectations correctly: This is a forum that is monitored by volunteers like and also sometimes persons for external companies that provided support services on behalf of Microsoft. None of these categories have direct contact with the product group to make such investigations.

The proper channel if you want to open a support case. That typically requires that you already have a support contract, and maybe one that goes beyond the most basic level.

That does not mean that your post here is completely meaningless, because if more people chime in and say that they see the same thing, that's an indication that there is a real issue. On the other hand, complete silence from the rest of the community may indicate that this is a problem in your environment rather than in SQL Server.

Personally, I have a lab-AG at home, but I'm travelling right now, and don't have access to it, so I cannot test.

Your answer

Erland Sommarskog 137.6K Reputation points MVP Volunteer Moderator

2026-09-25T20:30:58.5433333+00:00

Just to set your expectations correctly: This is a forum that is monitored by volunteers like and also sometimes persons for external companies that provided support services on behalf of Microsoft. None of these categories have direct contact with the product group to make such investigations.

The proper channel if you want to open a support case. That typically requires that you already have a support contract, and maybe one that goes beyond the most basic level.

That does not mean that your post here is completely meaningless, because if more people chime in and say that they see the same thing, that's an indication that there is a real issue. On the other hand, complete silence from the rest of the community may indicate that this is a problem in your environment rather than in SQL Server.

Personally, I have a lab-AG at home, but I'm travelling right now, and don't have access to it, so I cannot test.