check: added new config checklatencysamples to support average latency calculating (#282)

README.md

@@ -93,7 +93,7 @@ glider -config CONFIG_PATH
 glider -verbose -listen :8443 -forward SCHEME://HOST:PORT
 ```
 
-**Show help:**  `glider -help`
+**Help:**  `glider -help`
 
 <details>
 <summary>click to see details</summary>
@@ -222,7 +222,7 @@ glider 0.16.0, https://github.com/nadoo/glider
 
 </details>
 
-**Show Schemes:** `glider -scheme all`
+**Schemes:** `glider -scheme all`
 
 <details>
 <summary>click to see details</summary>
@@ -337,7 +337,7 @@ TLS and Websocket with a specified proxy protocol:
 
 </details>
 
-**Show Examples:** `glider -example`
+**Examples:** `glider -example`
 
 <details>
 <summary>click to see details</summary>

config.go

@@ -66,6 +66,7 @@ check=disable: disable health check`)
 	flag.IntVar(&conf.Strategy.CheckInterval, "checkinterval", 30, "fowarder check interval(seconds)")
 	flag.IntVar(&conf.Strategy.CheckTimeout, "checktimeout", 10, "fowarder check timeout(seconds)")
 	flag.IntVar(&conf.Strategy.CheckTolerance, "checktolerance", 0, "fowarder check tolerance(ms), switch only when new_latency < old_latency - tolerance, only used in lha mode")
+	flag.IntVar(&conf.Strategy.CheckLatencySamples, "checklatencysamples", 1, "use the average latency of the latest N checks")
 	flag.BoolVar(&conf.Strategy.CheckDisabledOnly, "checkdisabledonly", false, "check disabled fowarders only")
 	flag.IntVar(&conf.Strategy.MaxFailures, "maxfailures", 3, "max failures to change forwarder status to disabled")
 	flag.IntVar(&conf.Strategy.DialTimeout, "dialtimeout", 3, "dial timeout(seconds)")

rule/config.go

@@ -24,16 +24,17 @@ type Config struct {
 
 // Strategy configurations.
 type Strategy struct {
-	Strategy          string
-	Check             string
-	CheckInterval     int
-	CheckTimeout      int
-	CheckTolerance    int
-	CheckDisabledOnly bool
-	MaxFailures       int
-	DialTimeout       int
-	RelayTimeout      int
-	IntFace           string
+	Strategy            string
+	Check               string
+	CheckInterval       int
+	CheckTimeout        int
+	CheckTolerance      int
+	CheckLatencySamples int
+	CheckDisabledOnly   bool
+	MaxFailures         int
+	DialTimeout         int
+	RelayTimeout        int
+	IntFace             string
 }
 
 // NewConfFromFile returns a new config from file.
@@ -46,6 +47,7 @@ func NewConfFromFile(ruleFile string) (*Config, error) {
 	f.StringVar(&p.Strategy.Check, "check", "http://www.msftconnecttest.com/connecttest.txt#expect=200", "check=tcp[://HOST:PORT]: tcp port connect check\ncheck=http://HOST[:PORT][/URI][#expect=STRING_IN_RESP_LINE]\ncheck=file://SCRIPT_PATH: run a check script, healthy when exitcode=0, environment variables: FORWARDER_ADDR\ncheck=disable: disable health check")
 	f.IntVar(&p.Strategy.CheckInterval, "checkinterval", 30, "fowarder check interval(seconds)")
 	f.IntVar(&p.Strategy.CheckTimeout, "checktimeout", 10, "fowarder check timeout(seconds)")
+	f.IntVar(&p.Strategy.CheckLatencySamples, "checklatencysamples", 1, "use the average latency of the latest N checks")
 	f.IntVar(&p.Strategy.CheckTolerance, "checktolerance", 0, "fowarder check tolerance(ms), switch only when new_latency < old_latency - tolerance, only used in lha mode")
 	f.BoolVar(&p.Strategy.CheckDisabledOnly, "checkdisabledonly", false, "check disabled fowarders only")
 	f.IntVar(&p.Strategy.MaxFailures, "maxfailures", 3, "max failures to change forwarder status to disabled")

rule/group.go

@@ -266,13 +266,23 @@ func (p *FwdrGroup) check(fwdr *Forwarder, checker Checker) {
 		}
 
 		wait = 1
-		fwdr.SetLatency(int64(elapsed))
-		log.F("[check] %s: %s(%d), SUCCESS. elapsed: %s",
-			p.name, fwdr.Addr(), fwdr.Priority(), elapsed)
+		p.setLatency(fwdr, elapsed)
+		log.F("[check] %s: %s(%d), SUCCESS. elapsed: %s, Latency: %s",
+			p.name, fwdr.Addr(), fwdr.Priority(), elapsed, time.Duration(fwdr.Latency()))
 		fwdr.Enable()
 	}
 }
 
+func (p *FwdrGroup) setLatency(fwdr *Forwarder, elapsed time.Duration) {
+	newLatency := int64(elapsed)
+	if cnt := p.config.CheckLatencySamples; cnt > 1 {
+		if lastLagency := fwdr.Latency(); lastLagency > 0 {
+			newLatency = (lastLagency*(int64(cnt)-1) + int64(elapsed)) / int64(cnt)
+		}
+	}
+	fwdr.SetLatency(newLatency)
+}
+
 // Round Robin.
 func (p *FwdrGroup) scheduleRR(dstAddr string) *Forwarder {
 	return p.avail[atomic.AddUint32(&p.index, 1)%uint32(len(p.avail))]