我們知道壓力測試的軟件確實很多，諸如微軟的WAST，惠普的LoadRunner以及等等其他的，但這些軟件學習起來還是需要花費些時間，在選擇上實在頭痛，后來在郭欣的那本《構建高性能WEB站點》上看到了他介紹的這款Apache自帶的壓力測試工具ab，十分喜愛，于是今天終于有機會體驗下ab對網站的壓力測試。
實驗之前我的apache已經安裝了，操作系統：Ubuntu 10.04 VMware 7.0
1、先查看一下版本信息 ab -V（注意是大寫的V）
- studiogang@studiogang:~$ ab -V
- This is ApacheBench, Version 2.3 <$Revision: 655654 $>
- Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
- Licensed to The Apache Software Foundation, http://www.apache.org/
2、我們也可以使用小寫的v查看下ab命令的一些屬性 ab -v
- studiogang@studiogang:~$ ab -v
- ab: option requires an argument -- v
- ab: wrong number of arguments
- 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)
3、現在我們就對51CTO的網站進行一次壓力測試吧，使用命令ab -n1000 -c10 http://www.51cto.com/index.php，其中 -n1000 表示總請求數 -c10表示并發用戶數為10 http://www.51cto.com/index.php 表示請求的URL，下面是測試的結果，其中我們最關心的三個指標，我已經注釋出來了。
- studiogang@studiogang:~$ ab -n1000 -c10 http://www.51cto.com/index.php
- This is ApacheBench, Version 2.3 <$Revision: 655654 $>
- Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
- Licensed to The Apache Software Foundation, http://www.apache.org/
-
-
- Benchmarking www.51cto.com (be patient)
- Completed 100 requests
- Completed 200 requests
- Completed 300 requests
- Completed 400 requests
- Completed 500 requests
- Completed 600 requests
- Completed 700 requests
- Completed 800 requests
- Completed 900 requests
- Completed 1000 requests
- Finished 1000 requests
-
- /*WEB服務器用的是nginx*/
- Server Software: nginx
- Server Hostname: www.51cto.com
- Server Port: 80
-
- Document Path: /index.php
- Document Length: 154 bytes
-
- Concurrency Level: 10
- Time taken for tests: 74.373 seconds
- Complete requests: 1000
- Failed requests: 0
- Write errors: 0
- Non-2xx responses: 1000
- Total transferred: 330000 bytes
- HTML transferred: 154000 bytes
- /*大家最關心的指標之一，指的是吞吐率
- 相當于 LR 中的 每秒事務數 ，后面括號中的 mean 表示這是一個平均值*/
- Requests per second: 13.45 [#/sec] (mean)
- /*大家最關心的指標之二，指的是用戶平均請求等待時間
- 相當于 LR 中的 平均事務響應時間 ，后面括號中的 mean 表示這是一個平均值*/
- Time per request: 743.726 [ms] (mean)
- /*大家最關心的指標之三，指的是服務器平均請求處理時間
- Time per request: 74.373 [ms] (mean, across all concurrent requests)
- Transfer rate: 4.33 [Kbytes/sec] received
-
- Connection Times (ms)
- min mean[+/-sd] median max
- Connect: 129 163 245.3 145 3154
- Processing: 129 576 1510.8 147 11756
- Waiting: 129 567 1502.0 147 11756
- Total: 261 739 1543.7 294 11888
-
- Percentage of the requests served within a certain time (ms)
- 50% 294
- 66% 297
- 75% 304
- 80% 308
- 90% 1290
- 95% 3452
- 98% 7582
- 99% 7962
- 100% 11888 (longest request)
4、為了使結果更有對比性，我們將并發用戶更改為100個進行壓力測試，我這里只將三個指標貼出來。
- Requests per second: 190.95 [#/sec] (mean)
- Time per request: 523.694 [ms] (mean)
- Time per request: 5.237 [ms] (mean, across all concurrent requests)
5、將并發用戶改為200個進行測試
- Requests per second: 186.00 [#/sec] (mean)
- Time per request: 1149.433 [ms] (mean)
- Time per request: 5.747 [ms] (mean, across all concurrent requests)
6、500個并發用戶時的情況
- Requests per second: 180.99 [#/sec] (mean)
- Time per request: 2631.662 [ms] (mean)
- Time per request: 5.263 [ms] (mean, across all concurrent requests)
我們來分析下測試的結果，先對比下吞吐率，當并發用戶的時候吞吐率最高為190 reqs/s,當并發用戶數為200,500 吞吐率下降了，隨之用戶的等待時間更是明顯增加了，已經有2s的等待時間了。這說明性能明顯下降了。當然分析這個測試結果并不是說明51CTO的網站的并發用戶只能在500左右，因為我是在服務器負荷的情況下就行測試的，這顯然不能說明問題。另外我們在生產環境下測試的時候，最好能將測試結果做成報表，這樣可以非常清晰地對比出問題來，好了，我該準備下，給上面提交一份我們公司網站的測試報告了。