Errors and retries¶

Errors¶

All errors are subclasses of DRSError.

Error	Cause
`InvalidQueryError`	The query is not valid. The client did not send a request. Also a `ValueError`.
`AuthenticationError`	HTTP 401 or 403. The API key is missing, not valid or expired.
`UnknownDocTypeError`	The document type is not in DRS.
`RestrictedDocTypeError`	The document type is internal only. External keys cannot read it.
`BadRequestError`	HTTP 400. Usually a filter that is not valid. The message names filter fields that are not in the catalog.
`NotFoundError`	HTTP 404. Usually a file that does not exist.
`RateLimitError`	HTTP 429.
`ServerError`	HTTP 5xx, or a DRS system error.
`DRSConnectionError`	The client cannot connect to DRS.
`DRSTimeoutError`	The request took too long. A subclass of `DRSConnectionError`.
`ResponseValidationError`	The response does not have the expected shape.

UnknownFieldWarning is a warning, not an error. The client gives it for a filter field that is not in the catalog, and sends the filter anyway. See Filters.

Errors from the API are APIError subclasses. They have status_code, message and response attributes. You can pickle them, for example to send them from a worker process. A pickled error does not keep response.

APIError is the base class for errors from the API. It has these attributes:

status_code: The HTTP status code.
message: The error message from the API.
response: The httpx.Response.

Note

DRS sends some errors with HTTP status 200. The client finds these errors in the response body. For example, UnknownDocTypeError has status_code 200.

from faa_drs import DRSError, RestrictedDocTypeError

try:
    drs.list_documents("ICAO_ANNEX")
except RestrictedDocTypeError:
    print("Internal only.")
except DRSError as error:
    print(f"Failed: {error}")

Retries¶

The client retries these errors:

DRSConnectionError and DRSTimeoutError
RateLimitError
ServerError

The client waits longer before each retry. If the response has a Retry-After header, the client waits for that time, to a maximum of 30 seconds. The header can be a number of seconds or a date.

Set the number of retries with max_retries. The default is 3. Set it to 0 to stop retries.

drs = DRSClient(max_retries=5, timeout=120)

Logs¶

The client writes a warning to the faa_drs logger before each retry. The log does not contain the API key.

import logging

logging.basicConfig(level=logging.INFO)