Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.8.3 linux/amd64

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/root/go"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build244926751=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"

What did you do?

I want to do load-test using JMeter.
I let more than 2000 threads running concurrent while one thread means one request , and I find that many requests fail due to connecting time-out.

My code is as below:
`package main

import (
"golang.org/x/net/websocket"
"fmt"
"log"
"net/http"
)

func webHandler(ws *websocket.Conn) {
msg := make([]byte, 512)
n, err := ws.Read(msg)
if err != nil {
log.Println("ws.read ",err)
}
fmt.Printf("Receive: %s and read len: %d\n", msg[:n], n)

send_msg := string(msg[:n])
m, err := ws.Write([]byte(send_msg))
if err != nil {
	log.Println("ws.write ", err)
}
fmt.Printf("Send: %s\n and write len: %d\n", msg[:m], m)

}

func httpEchoHandler(w http.ResponseWriter, req *http.Request){
s := websocket.Server{Handler: websocket.Handler(webHandler)}
s.ServeHTTP(w, req)
}

func main() {
http.HandleFunc("/echo",httpEchoHandler)

err := http.ListenAndServe(":8080", nil)
if err != nil {
	log.Println("ListenAndServe: " + err.Error())
}else{
	log.Println("start server on port 8080")
}

}`

At the same time, I get log info:
2018/01/02 08:18:01 ws.read then return EOF

Can you help me exxplain Which condition will cause the read EOF error ?

What did you expect to see?

All threads run successfully

What did you see instead?

The log info “EOF ”