linux环境中ab命令简介及结果分析

ab（apache bench）是apache下的一个工具，主要用于对web站点做压力测试，

基础用法： 
其中-c选项为一次发送的请求数量，及并发量。
-n选项为请求次数。


实验测试：

1. [dev@web ~]$ ab -c 20 -n 50000 http://192.168.1.210/
2. This is ApacheBench, Version 2.3 <$Revision: 655654 $>
3. Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
4. Licensed to The Apache Software Foundation, http://www.apache.org/
6. Benchmarking 192.168.1.210 (be patient)
7. Completed 5000 requests
8. Completed 10000 requests
9. Completed 15000 requests
10. Completed 20000 requests
11. Completed 25000 requests
12. Completed 30000 requests
13. Completed 35000 requests
14. Completed 40000 requests
15. Completed 45000 requests
16. Completed 50000 requests
17. Finished 50000 requests
19. Server Software: nginx/1.6.2
20. Server Hostname: 192.168.1.210
21. Server Port: 80
23. Document Path: /
24. Document Length: 41005 bytes # 请求的页面大小
26. Concurrency Level: 20 # 并发量
27. Time taken for tests: 1180.733 seconds # 测试总共耗时
28. Complete requests: 50000 # 完成的请求
29. Failed requests: 0 # 失败的请求
30. Write errors: 0 # 错误
31. Total transferred: 2067550000 bytes # 总共传输数据量
32. HTML transferred: 2050250000 bytes
33. Requests per second: 42.35 [#/sec] (mean) # 每秒钟的请求量。（仅仅是测试页面的响应速度）
34. Time per request: 472.293 [ms] (mean) # 等于 Time taken for tests/(complete requests/concurrency level) 即平均请求等待时间（用户等待的时间）
35. Time per request: 23.615 [ms] (mean, across all concurrent requests) # 等于 Time taken for tests/Complete requests 即服务器平均请求响应时间 在并发量为1时 用户等待时间相同
36. Transfer rate: 1710.03 [Kbytes/sec] received # 平均每秒多少K，即带宽速率
39. Connection Times (ms)
40. min mean[+/-sd] median max
41. Connect: 0 1 18.5 0 1001
42. Processing: 38 471 534.1 155 9269
43. Waiting: 37 456 524.6 147 9259
44. Total: 40 472 534.5 155 9269
47. Percentage of the requests served within a certain time (ms)
48. 50% 155
49. 66% 571
50. 75% 783
51. 80% 871
52. 90% 1211
53. 95% 1603
54. 98% 1839
55. 99% 2003
56. 100% 9269 (longest request)

附录：

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    
    -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)