429 Too Many Requests

On further investigation, this might be an issue with Migrate Tools module. When running through the API, only a single item is imported per batch request. But running through Drush seems to circumvent the problem. Note when running through Drush, When using Drush, only 2 HTTP requests are made total.

Having now spent a couple of weeks regularly running into this error of "Too many requests" from Google's API, and having failed to request a rate limit increase from Google themselves, I took a hand at resolving this issue by extending this module's plugin class. Having put it together, I think solving the problem here through a configuration option would be the best solution.

I would suggest that a YAML configuration option be added like so:

  # Specify a cache lifetime in seconds. This will persist a local cache of
  # remote spreadsheet API request responses. This can be used to lower
  # the number of API requests to fit within rate limits and avoid a
  # "429 Too Many Requests" response from Google. Omit or set to 0 to
  # disable the cache.
  cache_lifetime: 10

Do you have the cache lifetime implemented in your plugin? If you open a MR I can take a look, I've seen the same myself when hitting through the UI but so far no issues just running with Drush.