If you are experiencing errors such as "User Rate Limit Exceeded", you are reaching or exceeding your destination Google Gmail, Calendar or Drive account's API quota. These quotas usually reset after a 24 hour period, and migrations can be rerun / continued.
These errors are explained by Google here Google Drive API Handle Errors and here Gmail API Usage Limits and they offer some solutions such as increasing the API quotas (manually or by request) or applying "exponential backoff". CloudMigrator already applies exponential backoff, but we have some other solutions available in the configuration:
(1) Reduce Max User Threads: Reduce the number of users that are concurrently running.
(2) (If Google Drive) Reduce the Drive thread count: General Migration Settings > Advanced Settings > Other Options > Drive Thread Count (reducing from 3 to 2 will make a big difference)
(3) Implement a delay on the export of items from the source: General Migration Settings > Advanced Settings > Other Options > Item Export Delay
(4) 'Destination Platform Migration Settings' > 'G Suite' > 'Drive Options' > 'Batch permissions' is also an option, whereby CloudMigrator will batch permission requests. This, however, is more error prone!
Note, you can chose one or a combination / all of the above, but essentially, each reduces the speed of your migration and should work around the quotas in place by Google.
User Rate Limit Exceeded
Please bear in mind, that the "user rate limit" is not visible in your G Suite cloud console, however, the above troubleshooting steps 2 and 3 will still help in this regard.
For more information, see Google Drive API User Rate Limit Exceeded or contact Google directly.
Contact Google Directly
API Rate Limiting is implemented by Google, and not something that CloudMigrator can control. If you are still experiencing rate limiting, it's best to contact Google directly.