You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
120 lines
3.5 KiB
120 lines
3.5 KiB
/*
|
|
* MinIO Cloud Storage, (C) 2017 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 cmd
|
|
|
|
import (
|
|
"sync"
|
|
"sync/atomic"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
dynamicTimeoutIncreaseThresholdPct = 0.33 // Upper threshold for failures in order to increase timeout
|
|
dynamicTimeoutDecreaseThresholdPct = 0.10 // Lower threshold for failures in order to decrease timeout
|
|
dynamicTimeoutLogSize = 16
|
|
maxDuration = time.Duration(1<<63 - 1)
|
|
)
|
|
|
|
// timeouts that are dynamically adapted based on actual usage results
|
|
type dynamicTimeout struct {
|
|
timeout int64
|
|
minimum int64
|
|
entries int64
|
|
log [dynamicTimeoutLogSize]time.Duration
|
|
mutex sync.Mutex
|
|
}
|
|
|
|
// newDynamicTimeout returns a new dynamic timeout initialized with timeout value
|
|
func newDynamicTimeout(timeout, minimum time.Duration) *dynamicTimeout {
|
|
return &dynamicTimeout{timeout: int64(timeout), minimum: int64(minimum)}
|
|
}
|
|
|
|
// Timeout returns the current timeout value
|
|
func (dt *dynamicTimeout) Timeout() time.Duration {
|
|
return time.Duration(atomic.LoadInt64(&dt.timeout))
|
|
}
|
|
|
|
// LogSuccess logs the duration of a successful action that
|
|
// did not hit the timeout
|
|
func (dt *dynamicTimeout) LogSuccess(duration time.Duration) {
|
|
dt.logEntry(duration)
|
|
}
|
|
|
|
// LogFailure logs an action that hit the timeout
|
|
func (dt *dynamicTimeout) LogFailure() {
|
|
dt.logEntry(maxDuration)
|
|
}
|
|
|
|
// logEntry stores a log entry
|
|
func (dt *dynamicTimeout) logEntry(duration time.Duration) {
|
|
entries := int(atomic.AddInt64(&dt.entries, 1))
|
|
index := entries - 1
|
|
if index < dynamicTimeoutLogSize {
|
|
dt.mutex.Lock()
|
|
dt.log[index] = duration
|
|
dt.mutex.Unlock()
|
|
}
|
|
if entries == dynamicTimeoutLogSize {
|
|
dt.mutex.Lock()
|
|
|
|
// Make copy on stack in order to call adjust()
|
|
logCopy := [dynamicTimeoutLogSize]time.Duration{}
|
|
copy(logCopy[:], dt.log[:])
|
|
|
|
// reset log entries
|
|
atomic.StoreInt64(&dt.entries, 0)
|
|
|
|
dt.mutex.Unlock()
|
|
|
|
dt.adjust(logCopy)
|
|
}
|
|
}
|
|
|
|
// adjust changes the value of the dynamic timeout based on the
|
|
// previous results
|
|
func (dt *dynamicTimeout) adjust(entries [dynamicTimeoutLogSize]time.Duration) {
|
|
|
|
failures, average := 0, int64(0)
|
|
for i := 0; i < len(entries); i++ {
|
|
if entries[i] == maxDuration {
|
|
failures++
|
|
} else {
|
|
average += int64(entries[i])
|
|
}
|
|
}
|
|
if failures < len(entries) {
|
|
average /= int64(len(entries) - failures)
|
|
}
|
|
|
|
timeOutHitPct := float64(failures) / float64(len(entries))
|
|
|
|
if timeOutHitPct > dynamicTimeoutIncreaseThresholdPct {
|
|
// We are hitting the timeout too often, so increase the timeout by 25%
|
|
timeout := atomic.LoadInt64(&dt.timeout) * 125 / 100
|
|
atomic.StoreInt64(&dt.timeout, timeout)
|
|
} else if timeOutHitPct < dynamicTimeoutDecreaseThresholdPct {
|
|
// We are hitting the timeout relatively few times, so decrease the timeout
|
|
average = average * 125 / 100 // Add buffer of 25% on top of average
|
|
|
|
timeout := (atomic.LoadInt64(&dt.timeout) + int64(average)) / 2 // Middle between current timeout and average success
|
|
if timeout < dt.minimum {
|
|
timeout = dt.minimum
|
|
}
|
|
atomic.StoreInt64(&dt.timeout, timeout)
|
|
}
|
|
|
|
}
|
|
|