The chunked download source sends large GET requests and then consumes data as it arrives. Sometimes it can stop reading from socket early and drop the in-flight data. The existing read-bytes metrics show only the number of consumed bytes, we we also want to know the number of requested bytes Refs #25770 (accounting of read-bytes) Fixes #25876 Signed-off-by: Pavel Emelyanov <xemul@scylladb.com> Closes scylladb/scylladb#25877