编写Go程序对Nginx服务器进行性能测试的方法
目前有很多提供Go语言HTTP应用服务的方法，但其中最好的选择取决于每个应用的实际情况。目前，Nginx看起来是每个新项目的标准Web服务器，即使在有其他许多不错Web服务器的情况下。然而，在Nginx上提供Go应用服务的开销是多少呢？我们需要一些nginx的特性参数（vhosts，负载均衡，缓存，等等）或者直接使用Go提供服务？如果你需要nginx，最快的连接机制是什么？这就是在这我试图回答的问题。该基准测试的目的不是要验证Go比nginx的快或慢。那将会很愚蠢。
下面是我们要比较不同的设置：
- Go HTTP standalone (as the control group)
- Nginx proxy to Go HTTP
- Nginx fastcgi to Go TCP FastCGI
- Nginx fastcgi to Go Unix Socket FastCGI
硬件
因为我们将在相同的硬件下比较所有设置，硬件选择的是廉价的一个。这不应该是一个大问题。
- Samsung 笔记本 NP550P5C-AD1BR
- Intel Core i7 3630QM @2.4GHz (quad core, 8 threads)
- CPU caches: (L1: 256KiB, L2: 1MiB, L3: 6MiB)
- RAM 8GiB DDR3 1600MHz
软件
- Ubuntu 13.10 amd64 Saucy Salamander (updated)
- Nginx 1.4.4 (1.4.4-1~saucy0 amd64)
- Go 1.2 (linux/amd64)
- wrk 3.0.4
设置
内核
只需很小的一点调整，将内核的limits调高。如果你对这一变量有更好的想法，请在写在下面评论处：
fs.nr_open 9999999
net.core.netdev_max_backlog 4096
net.core.rmem_max 16777216
net.core.somaxconn 65535
net.core.wmem_max 16777216
net.ipv4.ip_forward 0
net.ipv4.ip_local_port_range 1025 65535
net.ipv4.tcp_fin_timeout 30
net.ipv4.tcp_keepalive_time 30
net.ipv4.tcp_max_syn_backlog 20480
net.ipv4.tcp_max_tw_buckets 400000
net.ipv4.tcp_no_metrics_save 1
net.ipv4.tcp_syn_retries 2
net.ipv4.tcp_synack_retries 2
net.ipv4.tcp_tw_recycle 1
net.ipv4.tcp_tw_reuse 1
vm.min_free_kbytes 65536
vm.overcommit_memory 1
Limits
供root和www-data打开的最大文件数限制被配置为200000。
Nginx
有几个必需得Nginx调整。有人跟我说过，我禁用了gzip以保证比较公平。下面是它的配置文件/etc/nginx/nginx.conf：
user www-data;
worker_processes auto;
worker_rlimit_nofile 200000;
pid /var/run/nginx.pid;
events {
worker_connections 10000;
use epoll;
multi_accept on;
}
http {
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 300;
keepalive_requests 10000;
types_hash_max_size 2048;
open_file_cache max=200000 inactive=300s;
open_file_cache_valid 300s;
open_file_cache_min_uses 2;
open_file_cache_errors on;
server_tokens off;
dav_methods off;
include /etc/nginx/mime.types;
default_type application/octet-stream;
access_log /var/log/nginx/access.log combined;
error_log /var/log/nginx/error.log warn;
gzip off;
gzip_vary off;
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*.conf;
}
Nginx vhosts
upstream go_http {
server 127.0.0.1:8080;
keepalive 300;
}
server {
listen 80;
server_name go.http;
access_log off;
error_log /dev/null crit;
location / {
proxy_pass http://go_http;
proxy_http_version 1.1;
proxy_set_header Connection "";
}
}
upstream go_fcgi_tcp {
server 127.0.0.1:9001;
keepalive 300;
}
server {
listen 80;
server_name go.fcgi.tcp;
access_log off;
error_log /dev/null crit;
location / {
include fastcgi_params;
fastcgi_keep_conn on;
fastcgi_pass go_fcgi_tcp;
}
}
upstream go_fcgi_unix {
server unix:/tmp/go.sock;
keepalive 300;
}
server {
listen 80;
server_name go.fcgi.unix;
access_log off;
error_log /dev/null crit;
location / {
include fastcgi_params;
fastcgi_keep_conn on;
fastcgi_pass go_fcgi_unix;
}
}
Go源码
package main
import (
"fmt"
"log"
"net"
"net/http"
"net/http/fcgi"
"os"
"os/signal"
"syscall"
)
var (
abort bool
)
const (
SOCK = "/tmp/go.sock"
)
type Server struct {
}
func (s Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
body := "Hello World\n"
// Try to keep the same amount of headers
w.Header().Set("Server", "gophr")
w.Header().Set("Connection", "keep-alive")
w.Header().Set("Content-Type", "text/plain")
w.Header().Set("Content-Length", fmt.Sprint(len(body)))
fmt.Fprint(w, body)
}
func main() {
sigchan := make(chan os.Signal, 1)
signal.Notify(sigchan, os.Interrupt)
signal.Notify(sigchan, syscall.SIGTERM)
server := Server{}
go func() {
http.Handle("/", server)
if err := http.ListenAndServe(":8080", nil); err != nil {
log.Fatal(err)
}
}()
go func() {
tcp, err := net.Listen("tcp", ":9001")
if err != nil {
log.Fatal(err)
}
fcgi.Serve(tcp, server)
}()
go func() {
unix, err := net.Listen("unix", SOCK)
if err != nil {
log.Fatal(err)
}
fcgi.Serve(unix, server)
}()
<-sigchan
if err := os.Remove(SOCK); err != nil {
log.Fatal(err)
}
}
检查HTTP header
为公平起见，所有的请求必需大小相同。
HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 12
Content-Type: text/plain
Server: gophr
Date: Sun, 15 Dec 2013 14:59:14 GMT
$ curl -sI http://127.0.0.1:8080/ | wc -c
141
$ curl -sI http://go.http/
HTTP/1.1 200 OK
Server: nginx
Date: Sun, 15 Dec 2013 14:59:31 GMT
Content-Type: text/plain
Content-Length: 12
Connection: keep-alive
$ curl -sI http://go.http/ | wc -c
141
$ curl -sI http://go.fcgi.tcp/
HTTP/1.1 200 OK
Content-Type: text/plain
Content-Length: 12
Connection: keep-alive
Date: Sun, 15 Dec 2013 14:59:40 GMT
Server: gophr
$ curl -sI http://go.fcgi.tcp/ | wc -c
141
$ curl -sI http://go.fcgi.unix/
HTTP/1.1 200 OK
Content-Type: text/plain
Content-Length: 12
Connection: keep-alive
Date: Sun, 15 Dec 2013 15:00:15 GMT
Server: gophr
$ curl -sI http://go.fcgi.unix/ | wc -c
141
启动引擎
- 使用sysctl配置内核
- 配置Nginx
- 配置Nginx vhosts
- 用www-data启动服务
- 运行基准测试
基准测试
GOMAXPROCS = 1
Go standalone
# wrk -t100 -c5000 -d30s http://127.0.0.1:8080/
Running 30s test @ http://127.0.0.1:8080/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 116.96ms 17.76ms 173.96ms 85.31%
Req/Sec 429.16 49.20 589.00 69.44%
1281567 requests in 29.98s, 215.11MB read
Requests/sec: 42745.15
Transfer/sec: 7.17MB
Nginx + Go through HTTP
# wrk -t100 -c5000 -d30s http://go.http/
Running 30s test @ http://go.http/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 124.57ms 18.26ms 209.70ms 80.17%
Req/Sec 406.29 56.94 0.87k 89.41%
1198450 requests in 29.97s, 201.16MB read
Requests/sec: 39991.57
Transfer/sec: 6.71MB
Nginx + Go through FastCGI TCP
# wrk -t100 -c5000 -d30s http://go.fcgi.tcp/
Running 30s test @ http://go.fcgi.tcp/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 514.57ms 119.80ms 1.21s 71.85%
Req/Sec 97.18 22.56 263.00 79.59%
287416 requests in 30.00s, 48.24MB read
Socket errors: connect 0, read 0, write 0, timeout 661
Requests/sec: 9580.75
Transfer/sec: 1.61MB
Nginx + Go through FastCGI Unix Socket
# wrk -t100 -c5000 -d30s http://go.fcgi.unix/
Running 30s test @ http://go.fcgi.unix/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 425.64ms 80.53ms 925.03ms 76.88%
Req/Sec 117.03 22.13 255.00 81.30%
350162 requests in 30.00s, 58.77MB read
Socket errors: connect 0, read 0, write 0, timeout 210
Requests/sec: 11670.72
Transfer/sec: 1.96MB
GOMAXPROCS = 8
Go standalone
# wrk -t100 -c5000 -d30s http://127.0.0.1:8080/
Running 30s test @ http://127.0.0.1:8080/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 39.25ms 8.49ms 86.45ms 81.39%
Req/Sec 1.29k 129.27 1.79k 69.23%
3837995 requests in 29.89s, 644.19MB read
Requests/sec: 128402.88
Transfer/sec: 21.55MB
Nginx + Go through HTTP
Running 30s test @ http://go.http/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 336.77ms 297.88ms 632.52ms 60.16%
Req/Sec 2.36k 2.99k 19.11k 84.83%
2232068 requests in 29.98s, 374.64MB read
Requests/sec: 74442.91
Transfer/sec: 12.49MB
Nginx + Go through FastCGI TCP
# wrk -t100 -c5000 -d30s http://go.fcgi.tcp/
Running 30s test @ http://go.fcgi.tcp/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 217.69ms 121.22ms 1.80s 75.14%
Req/Sec 263.09 102.78 629.00 62.54%
721027 requests in 30.01s, 121.02MB read
Socket errors: connect 0, read 0, write 176, timeout 1343
Requests/sec: 24026.50
Transfer/sec: 4.03MB
Nginx + Go through FastCGI Unix Socket
# wrk -t100 -c5000 -d30s http://go.fcgi.unix/
Running 30s test @ http://go.fcgi.unix/
100 threads and 5000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 694.32ms 332.27ms 1.79s 62.13%
Req/Sec 646.86 669.65 6.11k 87.80%
909836 requests in 30.00s, 152.71MB read
Requests/sec: 30324.77
Transfer/sec: 5.09MB
结论
第一组基准测试时一些Nginx的设置还没有很好的优化（启用gzip，Go的后端没有使用keep-alive连接）。当改为wrk以及按建议优化Nginx后结果有较大差异。
当GOMAXPROCS=1时，Nginx的开销不是那么大，但当OMAXPROCS=8时差异就很大了。以后可能会再试一下其他设置。如果你需要使用Nginx像虚拟主机，负载均衡，缓存等特性，使用HTTP proxy，别使用FastCGI。有些人说Go的FastCGI还没有被很好优化，这也许就是测试结果中巨大差异的原因。
