minio/pkg/bucket/bandwidth/measurement.go
Ritesh H Shukla c2f16ee846
Add basic bandwidth monitoring for replication. (#10501)
This change tracks bandwidth for a bucket and object

- [x] Add Admin API
- [x] Add Peer API
- [x] Add BW throttling
- [x] Admin APIs to set replication limit
- [x] Admin APIs for fetch bandwidth
2020-10-09 20:36:00 -07:00

88 lines
2.7 KiB
Go

/*
* MinIO Cloud Storage, (C) 2020 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package bandwidth
import (
"sync"
"sync/atomic"
"time"
)
const (
// betaBucket is the weight used to calculate exponential moving average
betaBucket = 0.1 // Number of averages considered = 1/(1-betaObject)
)
// bucketMeasurement captures the bandwidth details for one bucket
type bucketMeasurement struct {
lock sync.Mutex
bytesSinceLastWindow uint64 // Total bytes since last window was processed
startTime time.Time // Start time for window
expMovingAvg float64 // Previously calculate sliding window
}
// newBucketMeasurement creates a new instance of the measurement with the initial start time.
func newBucketMeasurement(initTime time.Time) *bucketMeasurement {
return &bucketMeasurement{
startTime: initTime,
}
}
// incrementBytes add bytes reported for a bucket.
func (m *bucketMeasurement) incrementBytes(bytes uint64) {
atomic.AddUint64(&m.bytesSinceLastWindow, bytes)
}
// updateExponentialMovingAverage processes the measurements captured so far.
func (m *bucketMeasurement) updateExponentialMovingAverage(endTime time.Time) {
// Calculate aggregate avg bandwidth and exp window avg
m.lock.Lock()
defer func() {
m.startTime = endTime
m.lock.Unlock()
}()
if endTime.Before(m.startTime) {
return
}
duration := endTime.Sub(m.startTime)
bytesSinceLastWindow := atomic.SwapUint64(&m.bytesSinceLastWindow, 0)
if m.expMovingAvg == 0 {
// Should address initial calculation and should be fine for resuming from 0
m.expMovingAvg = float64(bytesSinceLastWindow) / duration.Seconds()
return
}
increment := float64(bytesSinceLastWindow) / duration.Seconds()
m.expMovingAvg = exponentialMovingAverage(betaBucket, m.expMovingAvg, increment)
}
// exponentialMovingAverage calculates the exponential moving average
func exponentialMovingAverage(beta, previousAvg, incrementAvg float64) float64 {
return (1-beta)*incrementAvg + beta*previousAvg
}
// getExpMovingAvgBytesPerSecond returns the exponential moving average for the bucket in bytes
func (m *bucketMeasurement) getExpMovingAvgBytesPerSecond() float64 {
m.lock.Lock()
defer m.lock.Unlock()
return m.expMovingAvg
}