What does the Snowflake OCSP warning mean?

If your project is connected to Snowflake, your server logs might show the following message:

WARNING!!! using fail-open to connect. Driver is connecting to an HTTPS endpoint without OCSP based Certificated Revocation checking as it could not obtain a valid OCSP Response to use from the CA OCSP responder. Details: AggregateError"

This is safe to ignore. The warning appears when OCSP cache entries expire, but your connection will still work normally. This is expected Snowflake driver behavior with "fail-open" mode.

Here is a quote from the snowflake-sdk team in a closed GitHub issue:

...
seems to be related how the OCSP local cache entries are only valid for a certain number of hours and after that period, they are considered expired.
...
Since the default behaviour of the driver is OCSP Fail-Open this is indeed just a warning in the logs and should not block the connection actually commencing.