geido commented on issue #30645: URL: https://github.com/apache/superset/issues/30645#issuecomment-2429290337
> @sadpandajoe @geido @eschutho I was able to pinpoint the problem. The reason for the failure is because the screenshot generation on 4.1.0 RC3 caches the screenshots using the `THUMBNAIL_CACHE_CONFIG` which is a [NullCache](https://flask-caching.readthedocs.io/en/latest/#nullcache) by default. A `NullCache` is a cache that does not cache anything, and that's why the frontend cannot find the screenshots and enters in a loop. The fix for this would be to make the default configuration of `THUMBNAIL_CACHE_CONFIG` similar to what we do with the Explore form data and save the thumbnails in the database using the `SupersetMetastoreCache`: > > ``` > THUMBNAIL_CACHE_CONFIG = { > "CACHE_TYPE": "SupersetMetastoreCache", > "CACHE_DEFAULT_TIMEOUT": // set a value > # Should the timeout be reset when retrieving a cached value? > "REFRESH_TIMEOUT_ON_RETRIEVAL": True, > # The following parameter only applies to `MetastoreCache`: > # How should entries be serialized/deserialized? > "CODEC": // define the appropriate codec > } > ``` > > Talking to @villebro about this issue, he raised a good point where previously Celery workers were not a hard requirement to install Superset but more of an optional feature. If the screenshot generation always requires Celery workers from now on, that could constitute a breaking change. Let me know your thoughts. Thanks @michael-s-molina we are currently discussing what the next steps should be for having Celery optional and the cache. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
