压力测试工具Ab简介

Apache安装包中自带的压力测试工具 Apache Benchmark(简称ab) 简单易用，这里就采用 ab作为压力测试工具了。

1.独立安装

[align=justify]通过 yum-utils中的yumdownload 工具下载安装包解开后就能得到独立的 ab可执行文件了。[/align]

yum install yum-utils.noarch
[align=justify] yumdownloader httpd-tools.x86_64[/align]

rpm2cpio httpd-*.rpm | cpio -idmv

2.参数详解

[align=justify]摘自： http://www.path8.net/tn/archives/5574[/align]
[align=justify]-n requests Number of requests to perform[/align]
[align=justify]//在测试会话中所执行的请求个数。默认时，仅执行一个请求[/align]
[align=justify]-c concurrency Number of multiple requests to make[/align]
[align=justify]//一次产生的请求个数。默认是一次一个。[/align]
[align=justify]-t timelimit Seconds to max. wait for responses[/align]
//测试所进行的最大秒数。其内部隐含值是 -n
50000。它可以使对服务器的测试限制在一个固定的总时间以内。默认时，没有时间限制。
[align=justify]-p postfile File containing data to POST[/align]
[align=justify]//包含了需要POST 的数据的文件 .[/align]
[align=justify]-T content-type Content-type header for POSTing[/align]
[align=justify]//POST数据所使用的Content-type头信息。[/align]
[align=justify]-v verbosity How much troubleshooting info to print[/align]
//设置显示信息的详细程度 -
4或更大值会显示头信息， 3或更大值可以显示响应代码 (404,
200等), 2或更大值可以显示警告和其他信息。 -V 显示版本号并退出。
[align=justify]-w Print out results in HTML tables[/align]
[align=justify]//以HTML 表的格式输出结果。默认时，它是白色背景的两列宽度的一张表。[/align]
[align=justify]-i Use HEAD instead of GET[/align]
[align=justify]// 执行HEAD 请求，而不是 GET。[/align]
[align=justify]-x attributes String to insert as table attributes[/align]
[align=justify]//[/align]
[align=justify]-y attributes String to insert as tr attributes[/align]
[align=justify]//[/align]
[align=justify]-z attributes String to insert as td or th attributes[/align]
[align=justify]//[/align]
[align=justify]-C attribute Add cookie, eg. 'Apache=1234. (repeatable)[/align]
[align=justify]//-C cookie-name=value 对请求附加一个 Cookie:行。 其典型形式是 name=value的一个参数对。此参数可以重复。[/align]
[align=justify]-H attribute Add Arbitrary header line, eg. 'Accept-Encoding: gzip'[/align]
[align=justify]Inserted after all normal header lines. (repeatable)[/align]
[align=justify]-A attribute Add Basic WWW Authentication, the attributes[/align]
[align=justify]are a colon separated username and password.[/align]
[align=justify]-P attribute Add Basic Proxy Authentication, the attributes[/align]
[align=justify]are a colon separated username and password.[/align]
[align=justify]//-P proxy-auth-username:password 对一个中转代理提供 BASIC认证信任。用户名和密码由一个 :隔开，并以base64 编码形式发送。无论服务器是否需要 (即, 是否发送了 401认证需求代码)，此字符串都会被发送。[/align]
[align=justify]-X proxy:port Proxyserver and port number to use[/align]
[align=justify]-V Print version number and exit[/align]
[align=justify]-k Use HTTP KeepAlive feature[/align]
[align=justify]-d Do not show percentiles served table.[/align]
[align=justify]-S Do not show confidence estimators and warnings.[/align]
[align=justify]-g filename Output collected data to gnuplot format file.[/align]
[align=justify]-e filename Output CSV file with percentages served[/align]
[align=justify]-h Display usage information (this message)[/align]
[align=justify]//-attributes 设置 属性的字符串 . 缺陷程序中有各种静态声明的固定长度的缓冲区。另外，对命令行参数、服务器的响应头和其他外部输入的解析也很简单，这可能会有不良后果。它没有完整地实现 HTTP/1.x; 仅接受某些' 预想'的响应格式。 strstr(3)的频繁使用可能会带来性能问题，即 , 你可能是在测试ab而不是服务器的性能。[/align]

3.输出解读

[align=justify]下面随便测试一个网页地址，来看下 ab输出的各项指标的含义。[/align]
[align=justify]===============================================================================[/align]

[align=justify][root@server23 bin]# ./ab -n 100 -c 5 http://test.com[/align] [align=justify]This is ApacheBench, Version 2.3 <$Revision: 655654 $>[/align]
[align=justify]Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/[/align] [align=justify]Licensed to The Apache Software Foundation, http://www.apache.org/[/align]
[align=justify]Benchmarking test.com (be patient).....done[/align]

[align=justify]Server Software: nginx[/align]
[align=justify]Server Hostname: test.com[/align]
[align=justify]Server Port: 80[/align]

[align=justify]Document Path: /[/align]
[align=justify]Document Length: 0 bytes[/align]

[align=justify]Concurrency Level: 5[/align]
[align=justify]Time taken for tests: 1.559 seconds[/align]
[align=justify]Complete requests: 100[/align]
[align=justify]Failed requests: 0[/align]
[align=justify]Write errors: 0[/align]
[align=justify]Non-2xx responses: 100[/align]
[align=justify]Total transferred: 21500 bytes[/align]
[align=justify]HTML transferred: 0 bytes[/align]
[align=justify]Requests per second: 64.15 [#/sec] (mean)[/align]
[align=justify]Time per request: 77.936 [ms] (mean)[/align]
[align=justify]Time per request: 15.587 [ms] (mean, across all concurrent requests)[/align]
[align=justify]Transfer rate: 13.47 [Kbytes/sec] received[/align]

[align=justify]Connection Times (ms)[/align]
[align=justify] min mean[+/-sd] median max[/align]
[align=justify]Connect: 36 37 0.7 37 39[/align]
[align=justify]Processing: 37 41 4.6 40 59[/align]
[align=justify]Waiting: 37 41 4.6 39 59[/align]
[align=justify]Total: 73 78 4.5 77 96[/align]

[align=justify]Percentage of the requests served within a certain time (ms)[/align]
[align=justify] 50% 77[/align]
[align=justify] 66% 78[/align]
[align=justify] 75% 79[/align]
[align=justify] 80% 79[/align]
[align=justify] 90% 81[/align]
[align=justify] 95% 95[/align]
[align=justify] 98% 95[/align]
[align=justify] 99% 96[/align]
[align=justify] 100% 96 (longest request)[/align]

[align=justify]===============================================================================[/align]
[align=justify]上面测试时用 -c参数指定并发连接数为5，下面是关键指标含义的解释：[/align]

Time per request: 77.936 [ms] (mean)

每批请求处理完成的平均时间

Time per request: 15.587 [ms] (mean, across all concurrent requests)
[align=justify] 每个请求处理完成的平均时间 =每批完成时间77.936除以并发数 5[/align]

[align=justify] 每秒能处理的的请求数 =1000ms除以15.587[/align]