prometheus/util/stats/timer.go
David Kaltschmidt c93e54d240 Adds execution timer stats to the range query
API consumers should be able to get insight into the query run times.
The UI currently measures total roundtrip times. This PR allows for more
fine grained metrics to be exposed.

* adds new timer for total execution time (queue + eval)

* expose new timer, queue timer, and eval timer in stats field of the
 range query response:
```json
{
  "status": "success",
  "data": {
    "resultType": "matrix",
    "result": [],
    "stats": {
      "execQueueTimeNs": 4683,
      "execTotalTimeNs": 2086587,
      "totalEvalTimeNs": 2077851
    }
  }
}
```

* stats field is optional, only set when query parameter `stats` is not
empty

Try it via
```sh
curl 'http://localhost:9090/api/v1/query_range?query=up&start=1486480279&end=1486483879&step=14000&stats=true'
```

Review feedback

* moved query stats json generation to query_stats.go
* use seconds for all query timers
* expose all timers available
* Changed ExecTotalTime string representation from Exec queue total time to Exec total time
2017-11-16 16:05:10 +01:00

114 lines
2.8 KiB
Go

// Copyright 2013 The Prometheus Authors
// 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 stats
import (
"bytes"
"fmt"
"sort"
"time"
)
// A Timer that can be started and stopped and accumulates the total time it
// was running (the time between Start() and Stop()).
type Timer struct {
name fmt.Stringer
created time.Time
start time.Time
duration time.Duration
}
// Start the timer.
func (t *Timer) Start() *Timer {
t.start = time.Now()
return t
}
// Stop the timer.
func (t *Timer) Stop() {
t.duration += time.Since(t.start)
}
// ElapsedTime returns the time that passed since starting the timer.
func (t *Timer) ElapsedTime() time.Duration {
return time.Since(t.start)
}
// Duration returns the duration value of the timer in seconds.
func (t *Timer) Duration() float64 {
return t.duration.Seconds()
}
// Return a string representation of the Timer.
func (t *Timer) String() string {
return fmt.Sprintf("%s: %s", t.name, t.duration)
}
// A TimerGroup represents a group of timers relevant to a single query.
type TimerGroup struct {
timers map[fmt.Stringer]*Timer
}
// NewTimerGroup constructs a new TimerGroup.
func NewTimerGroup() *TimerGroup {
return &TimerGroup{timers: map[fmt.Stringer]*Timer{}}
}
// GetTimer gets (and creates, if necessary) the Timer for a given code section.
func (t *TimerGroup) GetTimer(name fmt.Stringer) *Timer {
if timer, exists := t.timers[name]; exists {
return timer
}
timer := &Timer{
name: name,
created: time.Now(),
}
t.timers[name] = timer
return timer
}
// Timers is a slice of Timer pointers that implements Len and Swap from
// sort.Interface.
type Timers []*Timer
type byCreationTimeSorter struct{ Timers }
// Len implements sort.Interface.
func (t Timers) Len() int {
return len(t)
}
// Swap implements sort.Interface.
func (t Timers) Swap(i, j int) {
t[i], t[j] = t[j], t[i]
}
func (s byCreationTimeSorter) Less(i, j int) bool {
return s.Timers[i].created.Before(s.Timers[j].created)
}
// Return a string representation of a TimerGroup.
func (t *TimerGroup) String() string {
timers := byCreationTimeSorter{}
for _, timer := range t.timers {
timers.Timers = append(timers.Timers, timer)
}
sort.Sort(timers)
result := &bytes.Buffer{}
for _, timer := range timers.Timers {
fmt.Fprintf(result, "%s\n", timer)
}
return result.String()
}