The S3A connector supports
"an auditor", a plugin which is invoked
at the start of every filesystem API call,
and whose issued "audit span" provides a context
for all REST operations against the S3 object store.
The standard auditor sets the HTTP Referrer header
on the requests with information about the API call,
such as process ID, operation name, path,
and even job ID.
If the S3 bucket is configured to log requests, this
information will be preserved there and so can be used
to analyze and troubleshoot storage IO.
Contributed by Steve Loughran.
Change-Id: Ic0a105c194342ed2d529833ecc42608e8ba2f258