Here's an example of the message format we prefer to be consistent with https://github.com/mongodb/mongo/blob/11de948b0c50df7d12de09ae0f01e791fc5d70d7/src/mongo/db/catalog/index_catalog_impl.cpp#L122-L128
Check with the docs team to get a preferred url.
In order to implement exponential backoff, consider 'SampleEveryNth' and the mechanism in 'log_severity_suppressor.h'.