Connection handshake failed with 0x80090350 on an availability group replica. What the code means, why it says mirroring, and what to check.
Backup Error 3636: An Error Occurred While Processing BackupMetadata
Backup error 3636 appeared on a log backup taken on an availability group secondary after a log file was added on the primary. The secondary had not replayed the change. This post shows the queries I use to compare file lists and redo progress, tested on SQL Server 2025.
SQL SERVER – Install Error: Microsoft Cluster Service (MSCS) Cluster Verification Errors – Part 3
Part 3: one more reason SQL Server setup can fail the MSCS cluster verification errors rule during install or AddNode, as seen at a client, and the fix.
SQL SERVER – Always On Replica Disconnected After Changing SQL Server Service Account
After I changed the SQL Server service account in my lab, the Always On secondary replica went disconnected. Here is why the endpoint rejects the new account.
SQL SERVER – Slow SQL Server 2016 Installation in Cluster: RunRemoteDiscoveryAction
A client’s SQL Server 2016 Installation in Cluster hung at RunRemoteDiscoveryAction while setup ran discovery on the other node. Here is the cause of the delay.
SQL SERVER – Parallel Redo on AlwaysOn Secondary – DIRTY_PAGE_TABLE_LOCK
Redo lag and high DIRTY_PAGE_TABLE_LOCK waits hit a client’s AlwaysOn secondary. Here is how Parallel Redo in SQL Server 2016 causes them and what to do.
Windows Clusters in Different Domains: Deploying a Distributed Availability Group
After a merger, a client had Windows clusters in different domains that were connected but not trusted, and no wish to use certificates. Here are the steps I shared to deploy a Distributed Availability Group with NTLM pass-through authentication.