1.安裝ab命令

sudo apt-get install apache2-utils

2.ab命令参数说明

Usage: ab [options] [http[s]://]hostname[:port]/path  
Options are:  
  
//总的请求数   
-n requests Number of requests to perform宅   
  
//一次同时并发的请求数 总的请求数(n)=次数*一次并发数(c)   
-c concurrency Number of multiple requests to make  
  
-t timelimit Seconds to max. wait for responses  
-b windowsize Size of TCP send/receive buffer,in bytes  
-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 for POSTing,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.  
-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.  
-h Display usage information (this message)  
-Z ciphersuite Specify SSL/TLS cipher suite (See openssl ciphers)  
-f protocol Specify SSL/TLS protocol (SSL2,SSL3,TLS1,or ALL)

3.运行 ab -n 100 -c 10 http://www.meetu.hk/ 对 http://www.meetu.hk/ 进行100次请求，10个并发请求压力测试结果。

Server Software: lighttpd/1.4.20  
    Server Hostname: www.meetu.hk  
    Server Port: 80  
      
    Document Path: /  
    Document Length: 2095 bytes  
      
    Concurrency Level: 10  
      
    //整个测试持续的时间   
    Time taken for tests: 3.303 seconds  
      
    //完成的请求数量   
    Complete requests: 100  
    Failed requests: 0  
    Write errors: 0  
    Total transferred: 235200 bytes  
    HTML transferred: 209500 bytes  
      
    //平均每秒处理30个请求   
    Requests per second: 30.27 [#/sec] (mean)  
      
    //平均每个请求处理时间为330毫秒 注:这里将一次10个并发请求看成一个整体   
    Time per request: 330.335 [ms] (mean)  
      
    //平均每个并发请求处理 时间 为33毫秒   
    Time per request: 33.034 [ms] (mean,across all concurrent requests)  
    Transfer rate: 69.53 [Kbytes/sec] received  
      
    Connection Times (ms)  
    min mean[+/-sd] median max  
    Connect: 51 170 35.9 178 230  
    Processing: 60 153 64.5 121 263  
    Waiting: 55 148 64.4 115 258  
    Total: 235 322 59.9 299 437  
      
    Percentage of the requests served within a certain time (ms)  
      
    //在这100个请求中有50%在299毫秒内完成   
    50% 299  
      
    //在这100个请求中有66%在312毫秒内完成   
    66% 312  
    75% 383  
    80% 412  
    90% 431  
    95% 432  
    98% 436  
    99% 437  
    100% 437 (longest request)