apache已经带了一个测试工具: ab 

一般把apache压力测试称为AB测试. ab工具的位置在apache2的bin目录里.ab的使用是这样的: 
$Content$nbsp;./ab 
./ab: wrong number of arguments 
Usage: ./ab [options] [http://]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 
-p postfile File containing data to POST 
-T content-type Content-type header for POSTing 
-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 
-h Display usage information (this message) 
参数很多,一般我们用 -c 和 -n 参数就可以了. 例如: 
./ab -c 100 -n 10000 http://127.0.0.1/index.php 
这个表示同时处理100个请求并运行10000次index.php文件.