Production database connectivity issues starting at 10:22am today

Hi RJT72,
Welcome to Microsoft Q&A,

Based on the behavior described in the thread, this appears more consistent with a transient Azure SQL connectivity or network-routing issue rather than database corruption or an authentication problem.

The main indicators are:

The application was previously working normally before the issue started.

The failures were connection/time-out related.

The issue appears to have resolved after a limited time window, which is commonly seen with transient platform or network events.

In Azure SQL environments, similar connectivity interruptions can sometimes be associated with:

transient Azure gateway/network interruptions,

firewall or private endpoint routing inconsistencies,

DNS resolution delays,

outbound port 1433 filtering,

or temporary connectivity degradation between the application host and Azure SQL.

I would recommend checking the following to help confirm the root cause:

Review Azure Resource Health and Service Health for the affected timeframe.

Validate outbound connectivity to the SQL endpoint over port 1433.

Verify DNS resolution from the application or SHIR host.

Review firewall rules and private endpoint configuration if applicable.

If using retry-sensitive workloads, consider implementing transient retry logic for SQL connections.

Relevant Microsoft documentation:

https://learn.microsoft.com/en-us/azure/azure-sql/database/troubleshoot-common-errors-issues?view=azuresql

https://learn.microsoft.com/en-us/azure/azure-sql/database/resource-health-to-troubleshoot-connectivity?view=azuresql

https://techcommunity.microsoft.com/t5/fasttrack-for-azure/understanding-connectivity-issues-in-azure-sql-database/ba-p/3790298

Also, short-lived Azure-side transient events can occasionally occur without a broad public outage announcement, especially when the impact is limited to a specific cluster, gateway, or region.

Hope this helps. If the issue happens again, please share the exact error message, correlation/session ID, and timestamp so the connectivity event can be investigated further.

Hi RJT72,

Welcome to Microsoft Q&A,

A 30-minute connectivity window like this on Azure SQL Database typically points to one of three things: a platform reconfiguration/failover event, a transient resource limit hit, or planned maintenance. Here is how to trace the exact root cause.

1. Check Resource Health history Go to your Azure SQL Database in the portal --> Resource Health. It shows a health timeline including any "Degraded" or "Unavailable" events. Cross-reference with the 10:22 am window to see if Azure flagged anything on its end.
   1. https://learn.microsoft.com/en-us/azure/azure-sql/database/resource-health-to-troubleshoot-connectivity?view=azuresql
2. Query sys.event_log
   1. Run this from the master database to see connectivity failures logged by Azure

       SELECT * FROM sys.event_log WHERE event_type IN ('connectivity', 'deadlock', 'error') AND start_time >= '2026-05-13 10:15:00' AND start_time <= '2026-05-13 11:00:00' ORDER BY start_time DESC;
      

3. Check resource utilization at that time
   1. Run this from your database to see if CPU, sessions, or workers spiked

       SELECT end_time, avg_cpu_percent, max_worker_percent, max_session_percent
      

FROM sys.dm_db_resource_stats ORDER BY end_time DESC; ```

1. Check Intelligent Insights,
   1. If you have Diagnostic Settings enabled with Log Analytics, look for the SQLInsights or Errors log table and filter for the time window. This gives you the most detailed root cause breakdown.

Please Upvote and accept the answer if it helps!!