Transformation failures - Post-Mortem


Between March 30, 20:58 UTC and March 31, 6:15 UTC, some transformation jobs failed with an internal error. About 2% of all transformation jobs were affected. We sincerely apologize for this incident.

What Happened?

On March 30 at 20:58 UTC, we deployed a new version of the Transformation service which contained updated Snowflake ODBC drivers. The update was enforced by Snowflake as a security update patch. Unfortunately, the new version of the driver contained a critical bug which caused the driver to crash when some queries were running longer than one hour. This led to failed transformation jobs.

What Are We Doing About This?

We now treat all driver updates as major updates. This means they go through more careful deployment and monitoring so that we can detect possible problems faster. In the long term, we're working with Snowflake to update drivers in a more controlled manner.