Synchronous Availability Groups Don’t Always Mean Zero Data Loss

Synchronous commit Availability Groups are often assumed to guarantee zero data loss. In reality, that guarantee depends on configuration choices that are frequently misunderstood or left at their defaults.

In this short session, we’ll walk through two real-world scenarios where data can still be lost during failover, even when synchronous commit is enabled, both commonly overlooked in production systems.

You’ll see why SQL Server may acknowledge commits before they are hardened on a secondary, how this affects failover behavior, and what must be configured differently when zero data loss is a strict requirement.

This session focuses on correcting a common but dangerous assumption and provides practical guidance you can apply immediately in production environments.