AB Test 压力测试工具使用整理

Apache Bench，是 Apache 自带的压力测试工具。a可以对服务器进行访问压力测试。
系统安装 Apache Server，自带 ab 命令。

1. 概念

1. 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。
2. 并发连接数：某一时刻服务器所接受的请求数（会话数）。
3. 并发用户数：某一时刻服务器所接受的连接数，一个用户可能同时产生多个连接。
4. 用户平均请求等待时间：总请求数 / 并发用户数。
5. 服务器平均请求等待时间：处理完成所有请求数所花费的时间 / 总请求数。

2. 命令

➜  ~ ab
ab: wrong number of arguments
Usage: ab [options] [http[s]://]hostname[:port]/path
Options are:
    # 本次测试所发的总请求数
    -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
                    (TLS1, TLS1.1, TLS1.2 or ALL)

3. 测试示例

3.1 基础访问测试

ab -n 1000 -c 10 http://cms.test.com/

测试结果如下

Server Software:
Server Hostname:        cms.kaleidoapp.cn
Server Port:            80

Document Path:          /
Document Length:        2746 bytes

Concurrency Level:      10
Time taken for tests:   8.352 seconds
Complete requests:      1000
Failed requests:        0
Total transferred:      2981000 bytes
HTML transferred:       2746000 bytes
Requests per second:    119.74 [#/sec] (mean)
Time per request:       83.517 [ms] (mean)
Time per request:       8.352 [ms] (mean, across all concurrent requests)
Transfer rate:          348.57 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:       29   39  11.2     37     173
Processing:    33   43  12.0     42     190
Waiting:       32   43  12.0     41     189
Total:         62   82  17.8     79     226

Percentage of the requests served within a certain time (ms)
  50%     79
  66%     84
  75%     89
  80%     90
  90%     93
  95%     96
  98%    135
  99%    197
 100%    226 (longest request)

结果可以看出：

1. 吞吐率：119.74
2. 整个测试持续的时间：8.352s
3. 完成的请求数：1000
4. 失败的请求数：0
5. 总的网络传输量：2981000 bytes
6. HTML内容传输量：2746000 bytes
7. 用户平均请求等待时间：83.517 ms
8. 服务器平均请求处理时间：8.352 ms
9. 平均每秒网络上的流量：348.57 kb

网络消耗时间分解

展示最小、平均、方差、中位值、最大值。

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:       29   39  11.2     37     173
Processing:    33   43  12.0     42     190
Waiting:       32   43  12.0     41     189
Total:         62   82  17.8     79     226

请求处理时间分布

可以看出，95% 的请求用时在 95ms 以内，最长请求时间为 226ms。

Percentage of the requests served within a certain time (ms)
  50%     79
  66%     84
  75%     89
  80%     90
  90%     93
  95%     96
  98%    135
  99%    197
 100%    226 (longest request)

3.2 接口请求

ab -n 1000 -c 10 -p 'list.json' -T 'application/json' -H 'Authorization: token' -s 10 http://api.test.com/app/v1/list

说明：

-p 代表的是入参的 json 文件，或是 text 的键值对
-T 代表 contentType
-H 代表的是 http header 信息
-s 代表的是超时时间，单位是秒，默认是 30s