簡介
ab的全稱是ApacheBench，是 Apache 附帶的一個小工具，專門用於 HTTP Server 的benchmark testing，可以同時模擬多個併發請求。前段時間看到公司的開發人員也在用它作一些測試，看起來也不錯，很簡單，也很容易使用，所以今天花一點時間看了一下。
通過下面的一個簡單的例子和註釋，相信大家可以更容易理解這個工具的使用。
一個簡單的例子
/*在這個例子的一開始，我執行了這樣一個命令 ab -n 10 -c 10 http://www.google.com/。這個命令的意思是啓動 ab ，向 www.google.com 發送10個請求(-n 10) ，並每次發送10個請求(-c 10)——也就是說一次都發過去了。跟着下面的是 ab 輸出的測試報告，紅色部分是我添加的註釋。*/
C:\Program Files\Apache Software Foundation\Apache2.2\bin>ab -n 10 -c 10 http
This is ApacheBench, Version 2.0.40-dev <$Revision: 1.146 $> apache-2.0
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright 1997-2005 The Apache Software Foundation, http://www.apache.org/
Benchmarking www.google.com (be patient).....done
Server Software: GWS/2.1
Server Hostname: www.google.com
Server Port: 80
Document Path: /
Document Length: 230 bytes
Concurrency Level: 10
/*整個測試持續的時間*/
Time taken for tests: 3.234651 seconds
/*完成的請求數量*/
Complete requests: 10
/*失敗的請求數量*/
Failed requests: 0
Write errors: 0
Non-2xx responses: 10
Keep-Alive requests: 10
/*整個場景中的網絡傳輸量*/
Total transferred: 6020 bytes
/*整個場景中的HTML內容傳輸量*/
HTML transferred: 2300 bytes
Requests per second: 3.09 [#/sec] (mean)
/*大家最關心的指標之二，相當於 LR 中的 平均事務響應時間 ，後面括號中的 mean 表示這是一個平均值*/
Time per request: 3234.651 [ms] (mean)
/*這個還不知道是什麼意思，有知道的朋友請留言，謝謝 ^_^ */
Time per request: 323.465 [ms] (mean, across all concurrent requests)
/*平均每秒網絡上的流量，可以幫助排除是否存在網絡流量過大導致響應時間延長的問題*/
Transfer rate: 1.55 [Kbytes/sec] received
/*網絡上消耗的時間的分解，各項數據的具體算法還不是很清楚*/
Connection Times (ms)
min mean[+/-sd] median max
Connect: 20 318 926.1 30 2954
Processing: 40 2160 1462.0 3034 3154
Waiting: 40 2160 1462.0 3034 3154
Total: 60 2479 1276.4 3064 3184
/*下面的內容爲整個場景中所有請求的響應情況。在場景中每個請求都有一個響應時間，其中 50％ 的用戶響應時間小於 3064 毫秒，60 ％ 的用戶響應時間小於 3094 毫秒，最大的響應時間小於 3184 毫秒*/
Percentage of the requests served within a certain time (ms)
50% 3064
66% 3094
75% 3124
80% 3154
90% 3184
95% 3184
98% 3184
99% 3184
100% 3184 (longest request)
參數詳解
ab is a tool for benchmarking your Apache Hypertext Transfer Protocol(HTTP) server. It is designed to give you an impression of how your current Apache installation performs. This especially shows you how many requests per second your Apache installation is capable of serving.
ab是Apache超文本傳輸協議(HTTP)的性能測試工具。 其設計意圖是描繪當前所安裝的Apache的執行性能， 主要是顯示你安裝的Apache每秒可以處理多少個請求。
OPTIONS
-A auth-username:password
Supply BASIC Authentication credentials to the server. The user name and password are separated by a single : and sent on the wire base64 encoded. The string is sent regardless of whether the server needs it (i.e., has sent an 401 authentication needed).
對服務器提供BASIC認證信任。 用戶名和密碼由一個:隔開，並以base64編碼形式發送。 無論服務器是否需要(即, 是否發送了401認證需求代碼)，此字符串都會被髮送。
-c concurrency
Number of multiple requests to perform at a time. Default is one request at a time.
一次產生的請求個數。默認是一次一個。
-C cookie-name=value
Add a Cookie: line to the request. The argument is typically in the form of a name=value pair. This field is repeatable.
對請求附加一個Cookie:行。 其典型形式是name=value的一個參數對。 此參數可以重複。
-d Do not display the "percentage served within XX [ms] table".
(legacy support).
不顯示"percentage served within XX [ms] table"的消息(爲以前的版本提供支持)。
-e csv-file
Write a Comma separated value (CSV) file which contains for each percentage (from 1% to 100%) the time (in milliseconds) it took to serve that percentage of the requests. This is usually more useful than the 'gnuplot' file; as the results are already 'binned'.
產生一個以逗號分隔的(CSV)文件， 其中包含了處理每個相應百分比的請求所需要(從1%到100%)的相應百分比的(以毫秒爲單位)時間。 由於這種格式已經“二進制化”，所以比'gnuplot'格式更有用。
-g gnuplot-file
Write all measured values out as a 'gnuplot' or TSV (Tab separate values) file. This file can easily be imported into packages like Gnuplot, IDL, Mathematica, Igor or even Excel. The labels are on the first line of the file.
把所有測試結果寫入一個'gnuplot'或者TSV (以Tab分隔的)文件。 此文件可以方便地導入到Gnuplot, IDL, Mathematica, Igor甚至Excel中。 其中的第一行爲標題。
-h Display usage information.
顯示使用方法。
-H custom-header
Append extra headers to the request. The argument is typically in the form of a valid header line, containing a colon-separated field-value pair (i.e., "Accept-Encoding: zip/zop;8bit").
對請求附加額外的頭信息。 此參數的典型形式是一個有效的頭信息行，其中包含了以冒號分隔的字段和值的對 (如, "Accept-Encoding: zip/zop;8bit").
-i Do HEAD requests instead of GET.
執行HEAD請求，而不是GET。
-k Enable the HTTP KeepAlive feature, i.e., perform multiple
requests within one HTTP session. Default is no KeepAlive.
啓用HTTP KeepAlive功能，即, 在一個HTTP會話中執行多個請求。 默認是不啓用KeepAlive功能.
-n requests
Number of requests to perform for the benchmarking session. The default is to just perform a single request which usually leads to non-representative enchmarking results.
在測試會話中所執行的請求個數。 默認時，僅執行一個請求，但通常其結果不具有代表意義。
-p POST-file
File containing data to POST.
包含了需要POST的數據的文件.
-P proxy-auth-username:password
Supply BASIC Authentication credentials to a proxy en-route. The username and password are separated by a single : and sent on the wire base64 encoded. The string is sent regardless of whether the proxy needs it (i.e., has sent an 407 proxy authentication needed).
對一箇中轉代理提供BASIC認證信任。 用戶名和密碼由一個:隔開，並以base64編碼形式發送。 無論服務器是否需要(即, 是否發送了401認證需求代碼)，此字符串都會被髮送。
-q When processing more than 150 requests, ab outputs a progress count on stderr every 10% or 100 requests or so. The -q flag will suppress these messages.
如果處理的請求數大於150， ab每處理大約10%或者100個請求時，會在stderr輸出一個進度計數。 此-q標記可以抑制這些信息。
-s When compiled in (ab -h will show you) use the SSL protected https rather than the http protocol. This feature is experimental and very rudimentary. You probably do not want to use it.
用於編譯中(ab -h會顯示相關信息)使用了SSL的受保護的https， 而不是http協議的時候。此功能是實驗性的，也是很簡陋的。最好不要用。
-S Do not display the median and standard deviation values, nor display the warning/error messages when the average and median are more than one or two times the standard deviation apart. And default to the min/avg/max values. (legacy support).
不顯示中值和標準背離值， 而且在均值和中值爲標準背離值的1到2倍時，也不顯示警告或出錯信息。 默認時，會顯示 最小值/均值/最大值等數值。(爲以前的版本提供支持).
-t timelimit
Maximum number of seconds to spend for benchmarking. This implies a -n 50000 internally. Use this to benchmark the server within a fixed total amount of time. Per default there is no timelimit.
測試所進行的最大秒數。其內部隱含值是-n 50000。 它可以使對服務器的測試限制在一個固定的總時間以內。默認時，沒有時間限制。
-T content-type
Content-type header to use for POST data.
POST數據所使用的Content-type頭信息。
-v verbosity
Set verbosity level - 4 and above prints information on headers, 3 and above prints response codes (404, 200, etc.), 2 and above prints warnings and info.
設置顯示信息的詳細程度 - 4或更大值會顯示頭信息， 3或更大值可以顯示響應代碼(404, 200等), 2或更大值可以顯示警告和其他信息。
-V Display version number and exit.
顯示版本號並退出。
-w Print out results in HTML tables. Default table is two columns wide, with a white background.
以HTML表的格式輸出結果。默認時，它是白色背景的兩列寬度的一張表。
-x <table>-attributes
String to use as attributes for <table>. Attributes are inserted <table here >.
設置<table>屬性的字符串。 此屬性被填入<table這裏>.
-X proxy[:port]
Use a proxy server for the requests.
對請求使用代理服務器。
-y <tr>-attributes
String to use as attributes for <tr>.
設置<tr>屬性的字符串.
-z <td>-attributes
String to use as attributes for <td>.
設置<td>屬性的字符串.
BUGS
There are various statically declared buffers of fixed length. Combined with the lazy parsing of the command line arguments, the response headers from the server and other external inputs, this might bite you. It does not implement HTTP/1.x fully; only accepts some 'expected' forms of responses. The rather heavy use of strstr(3) shows up top in profile, which might indicate a performance problem; i.e., you would measure the ab performance rather than the server's.
程 序中有各種靜態聲明的固定長度的緩衝區。另外，對命令行參數、服務器的響應頭和其他外部輸入的解析也很簡單，這可能會有不良後果。它沒有完整地實現 HTTP/1.x; 僅接受某些'預想'的響應格式。strstr(3)的頻繁使用可能會帶來性能問題，即, 你可能是在測試ab而不是服務器的性能。
ab是Apache超文本傳輸協議(HTTP)的性能測試工具。 其設計意圖是描繪當前所安裝的Apache的執行性能， 主要是顯示你安裝的Apache每秒可以處理多少個請求。
OPTIONS
-A auth-username:password
Supply BASIC Authentication credentials to the server. The user name and password are separated by a single : and sent on the wire base64 encoded. The string is sent regardless of whether the server needs it (i.e., has sent an 401 authentication needed).
對服務器提供BASIC認證信任。 用戶名和密碼由一個:隔開，並以base64編碼形式發送。 無論服務器是否需要(即, 是否發送了401認證需求代碼)，此字符串都會被髮送。
-c concurrency
Number of multiple requests to perform at a time. Default is one request at a time.
一次產生的請求個數。默認是一次一個。
-C cookie-name=value
Add a Cookie: line to the request. The argument is typically in the form of a name=value pair. This field is repeatable.
對請求附加一個Cookie:行。 其典型形式是name=value的一個參數對。 此參數可以重複。
-d Do not display the "percentage served within XX [ms] table".
(legacy support).
不顯示"percentage served within XX [ms] table"的消息(爲以前的版本提供支持)。
-e csv-file
Write a Comma separated value (CSV) file which contains for each percentage (from 1% to 100%) the time (in milliseconds) it took to serve that percentage of the requests. This is usually more useful than the 'gnuplot' file; as the results are already 'binned'.
產生一個以逗號分隔的(CSV)文件， 其中包含了處理每個相應百分比的請求所需要(從1%到100%)的相應百分比的(以毫秒爲單位)時間。 由於這種格式已經“二進制化”，所以比'gnuplot'格式更有用。
-g gnuplot-file
Write all measured values out as a 'gnuplot' or TSV (Tab separate values) file. This file can easily be imported into packages like Gnuplot, IDL, Mathematica, Igor or even Excel. The labels are on the first line of the file.
把所有測試結果寫入一個'gnuplot'或者TSV (以Tab分隔的)文件。 此文件可以方便地導入到Gnuplot, IDL, Mathematica, Igor甚至Excel中。 其中的第一行爲標題。
-h Display usage information.
顯示使用方法。
-H custom-header
Append extra headers to the request. The argument is typically in the form of a valid header line, containing a colon-separated field-value pair (i.e., "Accept-Encoding: zip/zop;8bit").
對請求附加額外的頭信息。 此參數的典型形式是一個有效的頭信息行，其中包含了以冒號分隔的字段和值的對 (如, "Accept-Encoding: zip/zop;8bit").
-i Do HEAD requests instead of GET.
執行HEAD請求，而不是GET。
-k Enable the HTTP KeepAlive feature, i.e., perform multiple
requests within one HTTP session. Default is no KeepAlive.
啓用HTTP KeepAlive功能，即, 在一個HTTP會話中執行多個請求。 默認是不啓用KeepAlive功能.
-n requests
Number of requests to perform for the benchmarking session. The default is to just perform a single request which usually leads to non-representative enchmarking results.
在測試會話中所執行的請求個數。 默認時，僅執行一個請求，但通常其結果不具有代表意義。
-p POST-file
File containing data to POST.
包含了需要POST的數據的文件.
-P proxy-auth-username:password
Supply BASIC Authentication credentials to a proxy en-route. The username and password are separated by a single : and sent on the wire base64 encoded. The string is sent regardless of whether the proxy needs it (i.e., has sent an 407 proxy authentication needed).
對一箇中轉代理提供BASIC認證信任。 用戶名和密碼由一個:隔開，並以base64編碼形式發送。 無論服務器是否需要(即, 是否發送了401認證需求代碼)，此字符串都會被髮送。
-q When processing more than 150 requests, ab outputs a progress count on stderr every 10% or 100 requests or so. The -q flag will suppress these messages.
如果處理的請求數大於150， ab每處理大約10%或者100個請求時，會在stderr輸出一個進度計數。 此-q標記可以抑制這些信息。
-s When compiled in (ab -h will show you) use the SSL protected https rather than the http protocol. This feature is experimental and very rudimentary. You probably do not want to use it.
用於編譯中(ab -h會顯示相關信息)使用了SSL的受保護的https， 而不是http協議的時候。此功能是實驗性的，也是很簡陋的。最好不要用。
-S Do not display the median and standard deviation values, nor display the warning/error messages when the average and median are more than one or two times the standard deviation apart. And default to the min/avg/max values. (legacy support).
不顯示中值和標準背離值， 而且在均值和中值爲標準背離值的1到2倍時，也不顯示警告或出錯信息。 默認時，會顯示 最小值/均值/最大值等數值。(爲以前的版本提供支持).
-t timelimit
Maximum number of seconds to spend for benchmarking. This implies a -n 50000 internally. Use this to benchmark the server within a fixed total amount of time. Per default there is no timelimit.
測試所進行的最大秒數。其內部隱含值是-n 50000。 它可以使對服務器的測試限制在一個固定的總時間以內。默認時，沒有時間限制。
-T content-type
Content-type header to use for POST data.
POST數據所使用的Content-type頭信息。
-v verbosity
Set verbosity level - 4 and above prints information on headers, 3 and above prints response codes (404, 200, etc.), 2 and above prints warnings and info.
設置顯示信息的詳細程度 - 4或更大值會顯示頭信息， 3或更大值可以顯示響應代碼(404, 200等), 2或更大值可以顯示警告和其他信息。
-V Display version number and exit.
顯示版本號並退出。
-w Print out results in HTML tables. Default table is two columns wide, with a white background.
以HTML表的格式輸出結果。默認時，它是白色背景的兩列寬度的一張表。
-x <table>-attributes
String to use as attributes for <table>. Attributes are inserted <table here >.
設置<table>屬性的字符串。 此屬性被填入<table這裏>.
-X proxy[:port]
Use a proxy server for the requests.
對請求使用代理服務器。
-y <tr>-attributes
String to use as attributes for <tr>.
設置<tr>屬性的字符串.
-z <td>-attributes
String to use as attributes for <td>.
設置<td>屬性的字符串.
BUGS
There are various statically declared buffers of fixed length. Combined with the lazy parsing of the command line arguments, the response headers from the server and other external inputs, this might bite you. It does not implement HTTP/1.x fully; only accepts some 'expected' forms of responses. The rather heavy use of strstr(3) shows up top in profile, which might indicate a performance problem; i.e., you would measure the ab performance rather than the server's.
程 序中有各種靜態聲明的固定長度的緩衝區。另外，對命令行參數、服務器的響應頭和其他外部輸入的解析也很簡單，這可能會有不良後果。它沒有完整地實現 HTTP/1.x; 僅接受某些'預想'的響應格式。strstr(3)的頻繁使用可能會帶來性能問題，即, 你可能是在測試ab而不是服務器的性能。