websocket: from 1k to 100k on a simple raspeberry pi 3 model b by using a bit lower level of the new ws lib api and restore the previous sync.Map for server's live connections, relative: https://github.com/kataras/iris/issues/1178

Former-commit-id: 40da148afb66a42d47285efce324269d66ed3b0e

_examples/websocket/go-client-stress-test/client/main.go

@@ -6,6 +6,7 @@ import (
 	"math/rand"
 	"os"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/kataras/iris/websocket2"
@@ -16,7 +17,28 @@ var (
 	f   *os.File
 )
 
-const totalClients = 1200
+const totalClients = 100000
+
+var connectionFailures uint64
+
+var (
+	disconnectErrors []error
+	connectErrors    []error
+	errMu            sync.Mutex
+)
+
+func collectError(op string, err error) {
+	errMu.Lock()
+	defer errMu.Unlock()
+
+	switch op {
+	case "disconnect":
+		disconnectErrors = append(disconnectErrors, err)
+	case "connect":
+		connectErrors = append(connectErrors, err)
+	}
+
+}
 
 func main() {
 	var err error
@@ -26,29 +48,93 @@ func main() {
 	}
 	defer f.Close()
 
+	start := time.Now()
+
 	wg := new(sync.WaitGroup)
-	for i := 0; i < totalClients/2; i++ {
+	for i := 0; i < totalClients/4; i++ {
 		wg.Add(1)
 		go connect(wg, 5*time.Second)
 	}
 
-	for i := 0; i < totalClients/2; i++ {
+	for i := 0; i < totalClients/4; i++ {
+		wg.Add(1)
+		waitTime := time.Duration(rand.Intn(5)) * time.Millisecond
+		time.Sleep(waitTime)
+		go connect(wg, 7*time.Second+waitTime)
+	}
+
+	for i := 0; i < totalClients/4; i++ {
 		wg.Add(1)
 		waitTime := time.Duration(rand.Intn(10)) * time.Millisecond
 		time.Sleep(waitTime)
 		go connect(wg, 10*time.Second+waitTime)
 	}
 
+	for i := 0; i < totalClients/4; i++ {
+		wg.Add(1)
+		waitTime := time.Duration(rand.Intn(20)) * time.Millisecond
+		time.Sleep(waitTime)
+		go connect(wg, 25*time.Second+waitTime)
+	}
+
 	wg.Wait()
-	fmt.Println("ALL OK.")
-	time.Sleep(5 * time.Second)
+	fmt.Println("--------================--------------")
+	fmt.Printf("execution time [%s]", time.Since(start))
+	fmt.Println()
+
+	if connectionFailures > 0 {
+		fmt.Printf("Finished with %d/%d connection failures. Please close the server-side manually.\n", connectionFailures, totalClients)
+	}
+
+	if n := len(connectErrors); n > 0 {
+		fmt.Printf("Finished with %d connect errors:\n", n)
+		var lastErr error
+		var sameC int
+
+		for i, err := range connectErrors {
+			if lastErr != nil {
+				if lastErr.Error() == err.Error() {
+					sameC++
+					continue
+				}
+			}
+
+			if sameC > 0 {
+				fmt.Printf("and %d more like this...\n", sameC)
+				sameC = 0
+				continue
+			}
+
+			fmt.Printf("[%d] - %v\n", i+1, err)
+			lastErr = err
+		}
+	}
+
+	if n := len(disconnectErrors); n > 0 {
+		fmt.Printf("Finished with %d disconnect errors\n", n)
+		for i, err := range disconnectErrors {
+			if err == websocket.ErrAlreadyDisconnected {
+				continue
+			}
+
+			fmt.Printf("[%d] - %v\n", i+1, err)
+		}
+	}
+
+	if connectionFailures == 0 && len(connectErrors) == 0 && len(disconnectErrors) == 0 {
+		fmt.Println("ALL OK.")
+	}
+
+	fmt.Println("--------================--------------")
 }
 
 func connect(wg *sync.WaitGroup, alive time.Duration) {
-
 	c, err := websocket.Dial(nil, url, websocket.ConnectionConfig{})
 	if err != nil {
-		panic(err)
+		atomic.AddUint64(&connectionFailures, 1)
+		collectError("connect", err)
+		wg.Done()
+		return
 	}
 
 	c.OnError(func(err error) {
@@ -68,7 +154,7 @@ func connect(wg *sync.WaitGroup, alive time.Duration) {
 	go func() {
 		time.Sleep(alive)
 		if err := c.Disconnect(); err != nil {
-			panic(err)
+			collectError("disconnect", err)
 		}
 
 		wg.Done()
@@ -80,6 +166,8 @@ func connect(wg *sync.WaitGroup, alive time.Duration) {
 			break
 		}
 
-		c.Emit("chat", scanner.Text())
+		if text := scanner.Text(); len(text) > 1 {
+			c.Emit("chat", text)
+		}
 	}
 }

_examples/websocket/go-client-stress-test/client/test.data

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-
-Lose eyes get fat shew. Winter can indeed letter oppose way change tended now. So is improve my charmed picture exposed adapted demands. Received had end produced prepared diverted strictly off man branched. Known ye money so large decay voice there to. Preserved be mr cordially incommode as an. He doors quick child an point at. Had share vexed front least style off why him. 
-
-He unaffected sympathize discovered at no am conviction principles. Girl ham very how yet hill four show. Meet lain on he only size. Branched learning so subjects mistress do appetite jennings be in. Esteems up lasting no village morning do offices. Settled wishing ability musical may another set age. Diminution my apartments he attachment is entreaties announcing estimating. And total least her two whose great has which. Neat pain form eat sent sex good week. Led instrument sentiments she simplicity. 
-
-Months on ye at by esteem desire warmth former. Sure that that way gave any fond now. His boy middleton sir nor engrossed affection excellent. Dissimilar compliment cultivated preference eat sufficient may. Well next door soon we mr he four. Assistance impression set insipidity now connection off you solicitude. Under as seems we me stuff those style at. Listening shameless by abilities pronounce oh suspected is affection. Next it draw in draw much bred. 

_examples/websocket/go-client-stress-test/server/main.go

@@ -10,7 +10,7 @@ import (
 	"github.com/kataras/iris/websocket2"
 )
 
-const totalClients = 1200
+const totalClients = 100000
 
 func main() {
 	app := iris.New()