Fivetran: Multiple Managed/S3 data lake destinations are erroring out causing connection sync failure

This incident has been resolved. We have observed that instance rates are returning to normal levels and affected connectors are syncing successfully.

Incident Summary:

Description:
Fivetran: Multiple Managed/S3 data lake destinations were erroring out, causing connection sync failures.

Timeline:
Issue began on Aug 22, 2025, at 01:20 UTC
Resolved on Aug 22, 2025, at 15:32 UTC

Cause:
The issue was with Cloud NAT – port exhaustion, which led to subsequent sync failures.

Resolution:
Dynamic port allocation was enabled on the Cloud NAT on Fivetran’s end, mitigating the issue. Connections that were paused are being gradually unpaused in batches while monitoring relevant metrics to ensure stability.

The issue has been mitigated, sync failure rates have returned to normal, and we are continuing to monitor connections.

Our engineering team is still actively investigating the issue. While some connections have been restored, others are still failing. We are continuing to work towards a full resolution and will provide the next update as soon as more information is available.

Fix has been deployed, and we are seeing connections are getting restored; however, many connections are still failing. We are continuing to investigate the issue to restore the services fully

The issue has been identified and we are working to resolve it.