Implement unavailable service error retry strategy

[dkocher]

When service is unavailable with an error such as No tomes available we may want to have a retry strategy for requests enabled that is independent of the generic setting in Connection → Timeouts.

The service is temporarily unavailable. The human-readable message identifies the nature of the issue, in general we recommend retrying with an exponential backoff between retries in response to this error. ¹

Footnotes

1. https://www.backblaze.com/docs/cloud-storage-native-api-error-handling-and-status-codes ↩