newCtx, cancel := context.WithCancel(ctx)
	if !di.rwMutex.GetLock(newCtx, cancel, di.opsID, lockSource, dsync.Options{
		Timeout:       timeout.Timeout(),
		RetryInterval: timeout.RetryInterval(),
	}) {
		timeout.LogFailure()
		defer cancel()
		if err := newCtx.Err(); err == context.Canceled {
			return LockContext{ctx: ctx, cancel: func() {}}, err
		}
		return LockContext{ctx: ctx, cancel: func() {}}, OperationTimedOut{}
	}

	globalTierMetrics.Observe(tier, 200*time.Millisecond)
	expSuccess := 10
	expFailure := 5
	for range expSuccess {
		globalTierMetrics.logSuccess(tier)
	}
	for range expFailure {
		globalTierMetrics.logFailure(tier)
	}
	metrics := globalTierMetrics.Report()
	var succ, fail float64
	for _, metric := range metrics {
		switch metric.Description.Name {
		case tierRequestsSuccess:
			succ += metric.Value

			op.TimeToResponseNS = since.Nanoseconds()
			globalTierMetrics.Observe(tier, since)
			globalTierMetrics.logSuccess(tier)
		} else {
			op.Error = err.Error()
			globalTierMetrics.logFailure(tier)
		}

		logger.GetReqInfo(ctx).AppendTags("tierStats", op.String())
	}
}

// getTransitionedObjectReader returns a reader from the transitioned tier.