webbench最多可以模拟3万个并发连接去测试网站的负载能力，个人感觉要比Apache自带的ab压力测试工具好，安装使用也特别方便。
1、适用系统：Linux
2、编译安装：
引用
wget http://blog.s135.com/soft/linux/webbench/webbench-1.5.tar.gz
tar zxvf webbench-1.5.tar.gz
cd webbench-1.5
make && make install
如果遇到以下错误：
[root@localhost webbench-1.5]# make && make install
cc -Wall -ggdb -W -O -c -o webbench.o webbench.c
make: cc: Command not found
make: *** [webbench.o] Error 127
表示需要安装 gcc aptitude install gcc
3、使用：
引用
webbench -c 500 -t 30 http://127.0.0.1/test.jpg
参数说明：-c表示并发数，-t表示时间(秒)
4、测试结果示例：
引用
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.
Benchmarking: GET http://127.0.0.1/test.jpg
500 clients, running 30 sec.
Speed=3230 pages/min, 11614212 bytes/sec.
Requests: 1615 susceed, 0 failed.
========================================
接下来可以测试了
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
条件1：模拟200个客户端请求.
webbench -c 200 -t 60 http://127.0.0.1/index.php （-c 时间同时并发连接数，-t是请求持续的时间）
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.
Benchmarking: GET http://127.0.0.1/index.php
200 clients, running 60 sec.
Speed=61325 pages/min, 164563 bytes/sec.
Requests: 61325 susceed, 0 failed.
结果1：服务器响应 1022 page /sec,61325请求全部成功
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
请求2： 500 个客户端并发请求，流畅
webbench -c 500 -t 60 http://127.0.0.1/index.phpWebbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.
Benchmarking: GET http://127.0.0.1/index.php
500 clients, running 60 sec.
Speed=48949 pages/min, 133143 bytes/sec.
Requests: 48949 susceed, 0 failed.
结果2：48949 pages/min, 133143 bytes/sec ，响应顺利
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
请求3:1000个客户端并发请求
webbench -c 1000 -t 60 http://127.0.0.1/index.php
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.
Benchmarking: GET http://127.0.0.1/index.php
1000 clients, running 60 sec.
Speed=18342 pages/min, 52711 bytes/sec.
Requests: 18309 susceed, 33 failed.
结果3：响应延迟，并有失败现象
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
请求4:2000个客户端并发请求
webbench -c 2000 -t 60 http://127.0.0.1/index.php
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.
Benchmarking: GET http://127.0.0.1/index.php
2000 clients, running 60 sec.
Speed=585724 pages/min, 125593 bytes/sec.
Requests: 584688 susceed, 1036 failed.
结果4：失败数增多
----------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
请求5:10000个客户端并发请求
webbench -c 10000 -t 60 http://127.0.0.1/index.php
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.
Benchmarking: GET http://127.0.0.1/index.php
10000 clients, running 60 sec.
problems forking worker no. 7762
fork failed.: Resource temporarily unavailable
结果5：服务器挂了