Increased Error 429 "too many requests" and much slower API uploads

[zaneselvans]

Error 429: Too many requests

Over the last week we've started getting a lot of Error 429 "too many requests" responses from the Zenodo API, despite not changing anything about how we access Zenodo data, and are wondering if there's been a change to the rate limits, or the number of requests that are required to upload a file?

See this issue for more details. Note that we do not retry on 429 errors, so as to avoid making excessive requests. For other frequently transient error codes like 502 we retry a few times with exponential backoff.

Slow uploads to sandbox.zenodo.org

Over the same timeframe, our test uploads to the Zenodo sandbox have become much, much slower. So much so that we're now seeing the GitHub Action timeout after 6 hours (example). Has there been some kind of infrastructural change, or new bandwidth throttling?