ab简介
ab是Apache Web服务器自带的性能测试工具，对于web开发者基本上就是开机即用(安装有Apache服务就会带有ab)，
它能模拟并发请求，对web服务器进行压力性能测试。平时可用快速的拿来做性能评估，或者对接口进行模拟并发测试。
安装
一般情况下，安装了Apache服务，就会带有ab工具，无需特别安装。
如果没有，
-
在Ubuntu下：
sudo apt install apache2-utils -
Windows下，直接下载Apache程序包安装即可，将
apache2.4.41\bin路径加入环境变量path中。
参数说明
常用参数
-n：总请求次数（最小默认为1）
-c：并发次数（最小默认为1且不能大于总请求次数，如：10个请求，10个并发，实际就是1人请求1次）
-p：post参数文档路径（-p和-T参数要配合使用）
-T：header头内容类型（此处切记是大写英文字母T）
-C：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。
-H：对请求附加额外的头信息。此参数的典型形式是一个有效的头信息行，其中包含了以冒号分隔的字段和值的对(如,"Accept-Encoding:zip/zop;8bit")
可用ab -h 查看详细参数，如下：
xiaojun1024@test-pc:~$ ab -h
Usage: ab [options] [http[s]://]hostname[:port]/path
Options are:
-n requests Number of requests to perform
-c concurrency Number of multiple requests to make at a time
-t timelimit Seconds to max. to spend on benchmarking
This implies -n 50000
-s timeout Seconds to max. wait for each response
Default is 30 seconds
-b windowsize Size of TCP send/receive buffer, in bytes
-B address Address to bind to when making outgoing connections
-p postfile File containing data to POST. Remember also to set -T
-u putfile File containing data to PUT. Remember also to set -T
-T content-type Content-type header to use for POST/PUT data, eg.
'application/x-www-form-urlencoded'
Default is 'text/plain'
-v verbosity How much troubleshooting info to print
-w Print out results in HTML tables
-i Use HEAD instead of GET
-x attributes String to insert as table attributes
-y attributes String to insert as tr attributes
-z attributes String to insert as td or th attributes
-C attribute Add cookie, eg. 'Apache=1234'. (repeatable)
-H attribute Add Arbitrary header line, eg. 'Accept-Encoding: gzip'
Inserted after all normal header lines. (repeatable)
-A attribute Add Basic WWW Authentication, the attributes
are a colon separated username and password.
-P attribute Add Basic Proxy Authentication, the attributes
are a colon separated username and password.
-X proxy:port Proxyserver and port number to use
-V Print version number and exit
-k Use HTTP KeepAlive feature
-d Do not show percentiles served table.
-S Do not show confidence estimators and warnings.
-q Do not show progress when doing more than 150 requests
-l Accept variable document length (use this for dynamic pages)
-g filename Output collected data to gnuplot format file.
-e filename Output CSV file with percentages served
-r Don't exit on socket receive errors.
-m method Method name
-h Display usage information (this message)
-I Disable TLS Server Name Indication (SNI) extension
-Z ciphersuite Specify SSL/TLS cipher suite (See openssl ciphers)
-f protocol Specify SSL/TLS protocol
(SSL2, TLS1, TLS1.1, TLS1.2 or ALL)
-E certfile Specify optional client certificate chain and private key实例测试
对给定的url进行测试：
-
GET请求：
#请求URL要使用双引号括起来，否则ab无法识别&符号 xiaojun1024@test-pc:~$ ab -n 100 -c 10 "http://www.test.com/index.php?aa=1&bb=2" -
POST请求：
#注意：-p是参数文档路径，-T是大写英文字母， #post表单格式为：application/x-www-form-urlencoded xiaojun1024@test-pc:~$ ab -n 100 -c 10 -p ./query_params.txt -T application/x-www-form-urlencoded "http://www.test.com/index.php"./query_params.txt 文件内容
username=xiao&type=1结果分析
主要看三个数据
-
Requests per second：吞吐率
服务器并发处理能力的量化描述，单位是reqs/s，指的是某个并发用户数下单位时间内处理的请求数。某个并发用户数下单位时间内能处理的最大请求数，称之为最大吞吐率。
计算公式：总请求数 / 处理完成这些请求数所花费的时间，即
Request per second = Complete requests / Time taken for tests -
Time per request：上面的是用户平均请求等待时间
处理完成所有请求数所花费的时间/ （总请求数 / 并发用户数），即
Time per request = Time taken for tests /（ Complete requests / Concurrency Level）
- Time per request：下面的是服务器平均请求处理时间
处理完成所有请求数所花费的时间 / 总请求数，即
Time taken for / testsComplete requests
可以看到，它是吞吐率的倒数。
同时，它也=用户平均请求等待时间/并发用户数，即
Time per request / Concurrency Level
详细如下：
xiaojun1024@test-pc:~$ ab -n 10 -c 10 "http://www.test.com/index.php?aa=1&bb=2"
This is ApacheBench, Version 2.3 <$Revision: 1843412 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking www.xiaojun1024.com (be patient).....done
Server Software: nginx/1.16.1
Server Hostname: www.test.com.com
Server Port: 443
SSL/TLS Protocol: TLSv1.2,ECDHE-RSA-AES128-GCM-SHA256,2048,128
Server Temp Key: ECDH P-256 256 bits
TLS Server Name: www.xiaojun1024.com
Document Path: /
Document Length: 29542 bytes
Concurrency Level: 5
Time taken for tests: 0.923 seconds
Complete requests: 20
Failed requests: 0
Total transferred: 595540 bytes
HTML transferred: 590840 bytes
Requests per second: 21.66 [#/sec] (mean)
Time per request: 230.791 [ms] (mean)
Time per request: 46.158 [ms] (mean, across all concurrent requests)
Transfer rate: 629.99 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 41 61 22.7 50 113
Processing: 68 125 37.6 123 220
Waiting: 68 118 37.5 114 217
Total: 120 186 33.6 186 274
Percentage of the requests served within a certain time (ms)
50% 186
66% 201
75% 209
80% 209
90% 231
95% 274
98% 274
99% 274
100% 274 (longest request)