AWS AU2 Sydney IDM outage

Issue Summary:
On 14th September 2025, the Aurora MySQL instance became unreachable, impacting customer transactions. Connectivity was restored only after a manual restart of the instance.

Findings:
Maintenance Activity: OS-level patches were applied during the scheduled maintenance window.
Unexpected Behavior: Post-patching, the instance became unreachable. This was not an expected outcome of the patching process.
Recovery Action: Manual restart of the instance restored connectivity.
Impact: Temporary loss of database connectivity, resulting in disruption to transactions.

Root Cause:
The root cause appears to be an unexpected side effect of OS patching during the maintenance window. While such patches are designed to be non-disruptive, in this case, the patching process led to the instance becoming unreachable, requiring manual intervention.

There is a outage in AWS AU2 Sydney, IDM outage in iPaaS ca3s.