受限于本地端口数的分配，我想看看本地能起到多少个TCP client连接
本测试用例client和server都部署在同一台linux虚拟机上
查看进程打开的描述符数：102400（10万）
[root@bogon ~]# ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 15042 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 102400 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 15042 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited
再看看测试代码，client端：
package main
import (
_ "bytes"
"fmt"
"net"
"net/url"
_ "os"
"strconv"
"time"
)
var (
DefalutTimeout = 25 * time.Second
MaxClient = 70000
clientNum = 0
msg_nums = 0
)
func sockConn(daemon string, timeout time.Duration) (net.Conn, error) {
daemonURL, err := url.Parse(daemon)
//fmt.Printf("daemon url %v %v \n", daemonURL, daemonURL.Scheme)
if err != nil {
return nil, fmt.Errorf("could not parse url %q: %v", daemon, err)
}
var c net.Conn
switch daemonURL.Scheme {
case "unix":
return net.DialTimeout(daemonURL.Scheme, daemonURL.Path, timeout)
case "tcp":
return net.DialTimeout(daemonURL.Scheme, daemonURL.Host, timeout)
default:
return c, fmt.Errorf("unknown scheme %v (%s)", daemonURL.Scheme, daemon)
}
}
func sendData(socket net.Conn, n int, msg_num_chan chan int) {
buf := make([]byte, 10)
for {
_, err := socket.Write([]byte(strconv.Itoa(n)))
if err != nil {
fmt.Printf("Error reading:%s\n", err.Error())
clientNum--
return
}
//send reply
_, err = socket.Read(buf)
fmt.Printf("client %v\n", string(buf))
if err != nil {
fmt.Printf("Error send reply:%s\n", err.Error())
clientNum--
return
}
//time.Sleep(1 * time.Second)
msg_num_chan <- 1
buf = buf[0:]
}
}
func connectServer(msg_num_chan chan int) {
for i := 1; i <= MaxClient; i++ {
socket, err := sockConn("tcp://127.0.0.1:8088", DefalutTimeout)
if err != nil {
fmt.Printf("connect error:%s\n", err)
} else {
clientNum++
go sendData(socket, i, msg_num_chan)
}
}
}
func main() {
msg_num_chan := make(chan int)
connectServer(msg_num_chan)
go func() {
for msg_num := range msg_num_chan {
msg_nums += msg_num
}
}()
time.Sleep(10 * time.Second)
fmt.Printf("rec msg %d \n", msg_nums)
}
Server端：
package main
import (
"fmt"
"net"
"os"
"time"
)
const (
MAX_CONN_NUM = 100000
)
func EchoFunc(conn net.Conn) {
defer conn.Close()
buf := make([]byte, 10)
for {
_, err := conn.Read(buf)
if err != nil {
//println("Error reading:", err.Error())
return
}
//fmt.Printf("server %s\n", string(buf))
//send reply
_, err = conn.Write(buf)
if err != nil {
//println("Error send reply:", err.Error())
return
}
}
}
func main() {
listener, err := net.Listen("tcp", "127.0.0.1:8088")
if err != nil {
fmt.Println("error listening:", err.Error())
os.Exit(1)
}
defer listener.Close()
fmt.Printf("running ...\n")
var cur_conn_num int = 0
conn_chan := make(chan net.Conn)
ch_conn_change := make(chan int)
go func() {
for conn_change := range ch_conn_change {
cur_conn_num += conn_change
}
}()
go func() {
for _ = range time.Tick(5e9) {
fmt.Printf("cur conn num: %d\n", cur_conn_num)
}
}()
for i := 0; i < MAX_CONN_NUM; i++ {
go func() {
for conn := range conn_chan {
ch_conn_change <- 1
EchoFunc(conn)
ch_conn_change <- -1
}
}()
}
for {
conn, err := listener.Accept()
if err != nil {
println("Error accept:", err.Error())
return
}
conn_chan <- conn
}
}
最后看看server端执行结果:
[root@bogon mpro]# go run server.go running ... cur conn num: 0 cur conn num: 17452 cur conn num: 28233 cur conn num: 28233 cur conn num: 28233 ^C^Cexit status 2
client端执行结果:
connect error:dial tcp 127.0.0.1:8088: cannot assign requested address connect error:dial tcp 127.0.0.1:8088: cannot assign requested address connect error:dial tcp 127.0.0.1:8088: cannot assign requested address connect error:dial tcp 127.0.0.1:8088: cannot assign requested address connect error:dial tcp 127.0.0.1:8088: cannot assign requested address connect error:dial tcp 127.0.0.1:8088: cannot assign requested address
只能起到2万8个连接，最主要受限于端口数
本例只是测试client端的连接数，不是测试server的连接数
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