cmd/syncthing: Start CPU usage monitoring not from init (fixes #4183)

Starting stuff from init() is an antipattern, and the innerProcess
variable isn't 100% reliable. We should sort out the other uses of it as
well in due time.

Also removing the hack on innerProcess as I happened to see it and the
affected versions are now <1% users.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4185
This commit is contained in:
Jakob Borg 2017-05-31 18:14:04 +00:00 committed by Audrius Butkevicius
parent b49bbe82dd
commit 803da92ca9
5 changed files with 88 additions and 59 deletions

59
cmd/syncthing/cpuusage.go Normal file
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@ -0,0 +1,59 @@
// Copyright (C) 2017 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package main
import (
"math"
"time"
metrics "github.com/rcrowley/go-metrics"
)
const cpuTickRate = 5 * time.Second
type cpuService struct {
avg metrics.EWMA
stop chan struct{}
}
func newCPUService() *cpuService {
return &cpuService{
// 10 second average. Magic alpha value comes from looking at EWMA package
// definitions of EWMA1, EWMA5. The tick rate *must* be five seconds (hard
// coded in the EWMA package).
avg: metrics.NewEWMA(1 - math.Exp(-float64(cpuTickRate)/float64(time.Second)/10.0)),
stop: make(chan struct{}),
}
}
func (s *cpuService) Serve() {
// Initialize prevUsage to an actual value returned by cpuUsage
// instead of zero, because at least Windows returns a huge negative
// number here that then slowly increments...
prevUsage := cpuUsage()
ticker := time.NewTicker(cpuTickRate)
defer ticker.Stop()
for {
select {
case <-ticker.C:
curUsage := cpuUsage()
s.avg.Update(int64((curUsage - prevUsage) / time.Millisecond))
prevUsage = curUsage
s.avg.Tick()
case <-s.stop:
return
}
}
}
func (s *cpuService) Stop() {
close(s.stop)
}
func (s *cpuService) Rate() float64 {
return s.avg.Rate()
}

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@ -11,7 +11,6 @@ import (
"encoding/json"
"fmt"
"io/ioutil"
"math"
"net"
"net/http"
"os"
@ -69,6 +68,7 @@ type apiService struct {
configChanged chan struct{} // signals intentional listener close due to config change
started chan string // signals startup complete by sending the listener address, for testing only
startedOnce chan struct{} // the service has started successfully at least once
cpu rater
guiErrors logger.Recorder
systemLog logger.Recorder
@ -121,7 +121,11 @@ type connectionsIntf interface {
Status() map[string]interface{}
}
func newAPIService(id protocol.DeviceID, cfg configIntf, httpsCertFile, httpsKeyFile, assetDir string, m modelIntf, defaultSub, diskSub events.BufferedSubscription, discoverer discover.CachingMux, connectionsService connectionsIntf, errors, systemLog logger.Recorder) *apiService {
type rater interface {
Rate() float64
}
func newAPIService(id protocol.DeviceID, cfg configIntf, httpsCertFile, httpsKeyFile, assetDir string, m modelIntf, defaultSub, diskSub events.BufferedSubscription, discoverer discover.CachingMux, connectionsService connectionsIntf, errors, systemLog logger.Recorder, cpu rater) *apiService {
service := &apiService{
id: id,
cfg: cfg,
@ -142,6 +146,7 @@ func newAPIService(id protocol.DeviceID, cfg configIntf, httpsCertFile, httpsKey
startedOnce: make(chan struct{}),
guiErrors: errors,
systemLog: systemLog,
cpu: cpu,
}
return service
@ -847,30 +852,6 @@ func (s *apiService) flushResponse(resp string, w http.ResponseWriter) {
f.Flush()
}
// 10 second average. Magic alpha value comes from looking at EWMA package
// definitions of EWMA1, EWMA5. The tick rate *must* be five seconds (hard
// coded in the EWMA package).
var cpuTickRate = 5 * time.Second
var cpuAverage = metrics.NewEWMA(1 - math.Exp(-float64(cpuTickRate)/float64(time.Second)/10.0))
func init() {
if !innerProcess {
return
}
go func() {
// Initialize prevUsage to an actual value returned by cpuUsage
// instead of zero, because at least Windows returns a huge negative
// number here that then slowly increments...
prevUsage := cpuUsage()
for range time.NewTicker(cpuTickRate).C {
curUsage := cpuUsage()
cpuAverage.Update(int64((curUsage - prevUsage) / time.Millisecond))
prevUsage = curUsage
cpuAverage.Tick()
}
}()
}
func (s *apiService) getSystemStatus(w http.ResponseWriter, r *http.Request) {
var m runtime.MemStats
runtime.ReadMemStats(&m)
@ -899,7 +880,7 @@ func (s *apiService) getSystemStatus(w http.ResponseWriter, r *http.Request) {
res["connectionServiceStatus"] = s.connectionsService.Status()
// cpuUsage.Rate() is in milliseconds per second, so dividing by ten
// gives us percent
res["cpuPercent"] = cpuAverage.Rate() / 10 / float64(runtime.NumCPU())
res["cpuPercent"] = s.cpu.Rate() / 10 / float64(runtime.NumCPU())
res["pathSeparator"] = string(filepath.Separator)
res["uptime"] = int(time.Since(startTime).Seconds())
res["startTime"] = startTime

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@ -71,7 +71,7 @@ func TestStopAfterBrokenConfig(t *testing.T) {
}
w := config.Wrap("/dev/null", cfg)
srv := newAPIService(protocol.LocalDeviceID, w, "../../test/h1/https-cert.pem", "../../test/h1/https-key.pem", "", nil, nil, nil, nil, nil, nil, nil)
srv := newAPIService(protocol.LocalDeviceID, w, "../../test/h1/https-cert.pem", "../../test/h1/https-key.pem", "", nil, nil, nil, nil, nil, nil, nil, nil)
srv.started = make(chan string)
sup := suture.NewSimple("test")
@ -475,11 +475,12 @@ func startHTTP(cfg *mockedConfig) (string, error) {
connections := new(mockedConnections)
errorLog := new(mockedLoggerRecorder)
systemLog := new(mockedLoggerRecorder)
cpu := new(mockedCPUService)
addrChan := make(chan string)
// Instantiate the API service
svc := newAPIService(protocol.LocalDeviceID, cfg, httpsCertFile, httpsKeyFile, assetDir, model,
eventSub, diskEventSub, discoverer, connections, errorLog, systemLog)
eventSub, diskEventSub, discoverer, connections, errorLog, systemLog, cpu)
svc.started = addrChan
// Actually start the API service
@ -930,7 +931,7 @@ func TestEventMasks(t *testing.T) {
cfg := new(mockedConfig)
defSub := new(mockedEventSub)
diskSub := new(mockedEventSub)
svc := newAPIService(protocol.LocalDeviceID, cfg, "", "", "", nil, defSub, diskSub, nil, nil, nil, nil)
svc := newAPIService(protocol.LocalDeviceID, cfg, "", "", "", nil, defSub, diskSub, nil, nil, nil, nil, nil)
if mask := svc.getEventMask(""); mask != defaultEventMask {
t.Errorf("incorrect default mask %x != %x", int64(mask), int64(defaultEventMask))

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@ -427,34 +427,6 @@ func main() {
return
}
// ---BEGIN TEMPORARY HACK---
//
// Remove once v0.14.21-v0.14.22 are rare enough. Those versions,
// essentially:
//
// 1. os.Setenv("STMONITORED", "yes")
// 2. os.Setenv("STNORESTART", "")
//
// where the intention was for 2 to cancel out 1 instead of setting
// STNORESTART to the empty value. We check for exactly this combination
// and pretend that neither was set. Looking through os.Environ lets us
// distinguish. Luckily, we weren't smart enough to use os.Unsetenv.
matches := 0
for _, str := range os.Environ() {
if str == "STNORESTART=" {
matches++
}
if str == "STMONITORED=yes" {
matches++
}
}
if matches == 2 {
innerProcess = false
}
// ---END TEMPORARY HACK---
if innerProcess || options.noRestart {
syncthingMain(options)
} else {
@ -1093,7 +1065,10 @@ func setupGUI(mainService *suture.Supervisor, cfg *config.Wrapper, m *model.Mode
l.Warnln("Insecure admin access is enabled.")
}
api := newAPIService(myID, cfg, locations[locHTTPSCertFile], locations[locHTTPSKeyFile], runtimeOptions.assetDir, m, defaultSub, diskSub, discoverer, connectionsService, errors, systemLog)
cpu := newCPUService()
mainService.Add(cpu)
api := newAPIService(myID, cfg, locations[locHTTPSCertFile], locations[locHTTPSKeyFile], runtimeOptions.assetDir, m, defaultSub, diskSub, discoverer, connectionsService, errors, systemLog, cpu)
cfg.Subscribe(api)
mainService.Add(api)

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@ -0,0 +1,13 @@
// Copyright (C) 2017 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package main
type mockedCPUService struct{}
func (*mockedCPUService) Rate() float64 {
return 42
}