NewMetrics creates metrics to be used for monitoring congestion control.

AIMDController implements the Additive-Increase/Multiplicative-Decrease algorithm which is used in TCP congestion avoidance.

LimitedRetrier executes the initial request plus a configurable limit of subsequent retries.

Controller handles congestion by: - determining if calls to object storage can be retried - defining and enforcing a back-pressure mechanism - centralising retries & hedging.

Hedger orchestrates request "hedging", which is the process of sending a new request when the old request is taking too long, and returning the response that is received first.

Retrier orchestrates requests & subsequent retries (if configured).