How long does it take to complete the API call to storage? Your front end might not be configured for asynchronous work.
The 502 error returned by the nginx process might have various causes: an exception raised by the application or by an internal API call, or by timing issues, if a request takes too long. We need copy of your relevant log entries and the portions of your code related to the API calls to storage, to continue this investigation. Meanwhile, checking your app's routing handlers may prove of consequence. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/f4991005-c8eb-41e0-9d9e-7650c1917685%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
