HTTP 400 / preconditionFailed should be retried #2723

Activity

1. blunderbuss-gcf

   assigned

   daniel-sanche

   on Feb 28, 2026
2. codeXsidd commented on Mar 21, 2026

   

   codeXsidd

   on Mar 21, 2026

   More actions

   

   I have investigated and implemented a fix for this issue.

   Root Cause:
   The _should_retry_response function in googleapiclient/http.py relied on HTTP response codes to trigger retries but previously only parsed the JSON error details for 403 Forbidden statuses (specifically looking for userRateLimitExceeded and rateLimitExceeded). It did not extend this logic to 400 Bad Request errors.

   Solution:
   I updated _should_retry_response to parse the JSON content for both 403 and 400 status codes.
   If the API returns a 400 Bad Request, the client will examine the JSON error response block, and if the "reason" is either "failedPrecondition" or "preconditionFailed", the response is now flagged to be retried with exponential backoff.

   Changes made:

   • googleapiclient/http.py: Refactored the JSON parsing block in _should_retry_response to apply to http_client.BAD_REQUEST as well. Added a condition to return True for retrying when encountering a failedPrecondition reason.
   • tests/test_http.py: Added a test_retry_400_failed_precondition mock test to verify the client correctly enters the sleep/retry loop rather than failing fast when a 400 preconditions error is received.

   It handles the issue perfectly using the project's existing error-parsing conventions. Let me know if you need anything else!
3. codeXsidd

   added 2 commits that reference this issue on Mar 21, 2026

   Fix googleapis#2723: Retry on HTTP 400 failedPrecondition

   This issue will close once commit 50a5f32 is merged into the 'main' branch.

   50a5f32

   fix(http): retry on HTTP 400 failedPrecondition

   ...

   This issue will close once commit 806eab9 is merged into the 'main' branch.

   806eab9
4. daniel-sanche

   assigned

   ohmayr

   on Jun 15, 2026
5. daniel-sanche

   added

   priority: p2Moderately-important priority. Fix may not be included in next release.Moderately-important priority. Fix may not be included in next release.

   type: feature request‘Nice-to-have’ improvement, new feature or different behavior or design.‘Nice-to-have’ improvement, new feature or different behavior or design.

   type: bugError or flaw in code with unintended results or allowing sub-optimal usage patterns.Error or flaw in code with unintended results or allowing sub-optimal usage patterns.

   priority: p3Desirable enhancement or fix. May not be included in next release.Desirable enhancement or fix. May not be included in next release.

   and removed

   type: feature request‘Nice-to-have’ improvement, new feature or different behavior or design.‘Nice-to-have’ improvement, new feature or different behavior or design.

   on Jun 15, 2026
6. parthea

   removed

   priority: p2Moderately-important priority. Fix may not be included in next release.Moderately-important priority. Fix may not be included in next release.

   on Aug 17, 2026