一、http_load
程序非常小，解压后也不到100K
http_load以并行复用的方式运行，用以测试web服务器的吞吐量与负载。但是它不同于大多数压力测试工
具，它可以以一个单一的进程运行，一般不会把客户机搞死。还可以测试HTTPS类的网站请求。
下载安装：
wget http://www.acme.com/software/http_load/http_load-14aug2014.tar.gz
tar zxvf http_load-14aug2014.tar.gz
cd http_load-14aug2014
make && make install
命令格式：
http_load [-checksum] [-throttle] [-proxy host:port] [-verbose] [-timeout secs]
[-sip sip_file]
-parallel N | -rate N [-jitter]
-fetches N | -seconds N
url_file
使用示例：
http_load -parallel 10 -fetches 100 url_file
url_file文件内容：
http://www.baidu.com/
结果说明：
100 fetches, 10 max parallel,1.06255e+07 bytes, in 2.48953 seconds
#请求数，最大进程数，传输数据总计，运行用时
106255 mean bytes/connection #每个请求/连接传输的数据量
40.1683 fetches/sec, 4.26808e+06 bytes/sec #每秒请求数,每秒传输的数据量
msecs/connect: 0.0879 mean, 0.236 max, 0.028 min #平均响应时间，最大响应时间，最小响应时间
msecs/first-response: 238.966 mean, 350.087 max, 98.128 min #
HTTP response codes:
code 200 -- 100要注意是否系统遇到了瓶颈。特殊说明：测试结果中主要的指标是 fetches/sec、msecs/connect 这个选项，即服务器每秒能够响应的查询次数，
用这个指标来衡量性能。似乎比 apache的ab准确率要高一些，也更有说服力一些。Qpt-每秒响应用户数和response time，每连接响应用户时间。
测试的结果主要也是看这两个值。当然仅有这两个指标并不能完成对性能的分析，我们还需要对服务器的
cpu、men进行分析，才能得出结论
二、webbench
webbench是Linux下的一个网站压力测试工具，最多可以模拟3万个并发连接去测试网站的负载能力。
下载安装：
wget http://home.tiscali.cz/~cz210552/distfiles/webbench-1.5.tar.gz
tar zxvf webbench-1.5.tar.g
cd webbench-1.5
make && make install
命令格式：
使用示例：
结果说明：三、ab
ab是apache自带的一款功能强大的测试工具
命令格式：
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 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.
-h Display usage information (this message)
-Z ciphersuite Specify SSL/TLS cipher suite (See openssl ciphers)
-f protocol Specify SSL/TLS protocol
(SSL3, TLS1, TLS1.1, TLS1.2 or ALL)
使用示例：
ab -c10 n100 http://www.baidu.com
结果说明：
Benchmarking www.baidu.com (be patient).....done
Server Software: BWS/1.1
Server Hostname: www.baidu.com
Server Port: 80
Document Path: /
Document Length: 95852 bytes
Concurrency Level: 10
Time taken for tests: 1.406 seconds
Complete requests: 100
Failed requests: 97
(Connect: 0, Receive: 0, Length: 97, Exceptions: 0)
Total transferred: 9674753 bytes
HTML transferred: 9572326 bytes
Requests per second: 71.13 [#/sec] (mean)
Time per request: 140.584 [ms] (mean)
Time per request: 14.058 [ms] (mean, across all concurrent requests)
Transfer rate: 6720.53 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 24 32 4.6 33 41
Processing: 74 102 20.6 101 248
Waiting: 26 37 15.5 35 182
Total: 99 134 24.0 134 281
Percentage of the requests served within a certain time (ms)
50% 134
66% 143
75% 153
80% 154
90% 155
95% 159
98% 170
99% 281
100% 281 (longest request)四、Siege
一款开源的压力测试工具，可以根据配置对一个WEB站点进行多用户的并发访问，记录每个用户所有请求过程的相应时间，并在一定数量的并发访问下重复进行。
官方：http://www.joedog.org/
下载安装：
wget http://download.joedog.org/siege/siege-latest.tar.gz
tar -zxvf siege-latest.tar.gz
cd siege-latest
./configure
make&&make install
命令格式：
使用示例：
siege -c 200 -r 10 -f example.url
结果说明：
Lifting the server siege… done.
Transactions: 3419263 hits #完成419263次处理
Availability: 100.00 % #100.00 % 成功率
Elapsed time: 5999.69 secs #总共用时
Data transferred: 84273.91 MB #共数据传输84273.91 MB
Response time: 0.37 secs #相应用时1.65秒：显示网络连接的速度
Transaction rate: 569.91 trans/sec #均每秒完成 569.91 次处理：表示服务器后
Throughput: 14.05 MB/sec #平均每秒传送数据
Concurrency: 213.42 #实际最高并发数
Successful transactions: 2564081 #成功处理次数
Failed transactions: 11 #失败处理次数
Longest transaction: 29.04 #每次传输所花最长时间
Shortest transaction: 0.00 #每次传输所花最短时间