Intermittent 404 responses

[dchiquito]

Sometimes the backend will respond a 404 for no apparent reason. Sentry has only caught it when fetching available sample files (https://sentry.io/organizations/kitware-data/issues/1327518191/), but I've personally seen it several times when fetching the loadings plot (/api/v1/csv/{uuid}/plot/loadings). In those cases, corresponding requests for the PCA plot succeeded, and everything worked after refreshing the page.

My hypothesis is that the problem is that the error is being thrown from the views.load_validated_csv_file annotation:

def load_validated_csv_file(func):

    @wraps(func)
    def wrapped(csv_id: str, *arg, **kwargs):
        csv_file = ValidatedMetaboliteTable.query \
            .filter_by(csv_file_id=csv_id) \
            .first_or_404()
        return func(csv_file, *arg, **kwargs)

    return wrapped

Somehow the database isn't finding a validated table that is there for requests made before and after the error occurs.