HA/DR & migration planningBank with fintech programs, anonymized × red9CS-0574
Planned a fintech bank off an end-of-support SQL Server and pulled an overloaded HA node back into range
The problem. A bank that sponsors fintech programs was still running production on SQL Server 2016, which loses extended support on July 14, 2026. One Availability Group node was carrying more than its share of the load and sitting at 269% SQL usage, which is where deadlocks and stalls start showing up under pressure.
What we did. We ran the first quarterly business review, set a parallel plan to migrate off SQL Server 2016 ahead of the deadline, and worked through the workload split so the overloaded node came back into a healthy range. This is a findings-and-plan engagement, so the numbers below reflect the estate as a whole rather than one query.
Red9 · Findings & Impact
Overloaded HA node
269%
SQL usage on one node before the workload was rebalanced.
Deadlocks on that node
92% lower
Once the load was spread and the plan was in place.
Version risk
off SQL 2016, planned
Migration set to land before the July 14, 2026 end of extended support.
HA node usage
269% → in range
rebalanced
Migration
Off SQL 2016
planned
How to read these. The 269% is the SQL usage the overloaded node showed before we spread the workload, and the 92% is the drop in deadlocks on that node afterward. The migration off SQL Server 2016 is scheduled ahead of the July 14, 2026 support deadline. All of it comes from the bank's own monitoring.
The result. The overloaded node is back in a healthy range with deadlocks down 92%, and the bank has a dated plan to be off SQL Server 2016 before support ends instead of scrambling after it does.
The technical detail
What the review found. Production ran on SQL Server 2016 with one Availability Group node pinned near 269% SQL usage, which drove deadlocks and left no headroom for a bad day.
What we planned and changed (details generalized for privacy):
-- Availability Group node sat at ~269% SQL usage, deadlocks climbing.
# 1. Rebalanced workload across the AG so no single node carried the peak.
# 2. Parallel migration plan: SQL Server 2016 -> supported build before 2026-07-14.
# 3. Deadlock monitoring in place; node deadlocks fell ~92% after the rebalance.
Spreading the workload pulled the node out of the danger zone, deadlocks dropped about 92%, and the migration off SQL Server 2016 is scheduled ahead of the support deadline.