If you use readable secondaries in Availability Groups or Read-Scale out instances in Azure SQL Managed Instance, you may have queries fail repeatedly if there is a glitch and statistics are not successfully “refreshed” on the secondary replica. Those queries may keep failing until you manually intervene.
This has been the case for a few years, and it’s unclear if Microsoft will fix this. There is a well established support deflection article which documents the issue and provides ‘workarounds’.
As a user on StackExchange wrote in September of 2022, “This is an outstanding bug in SQL Server which has been ignored for quite some time, unfortunately.” Based on a link provided in that post, it appears that feedback was provided for this as far back as SQL Server 2012, when AGs were introduced.
Just how viable are readable secondaries / scale-out read servers for production use if it’s acceptable for queries to fail at an undocumented/unknown rate?