webbench压力测试的疑问

Question

各位大侠，大家好!我在windows 平台下用squid+tomcat(2个)组建了一个小的集群环境，我想测试下是不是squid的缓存起到了做用，同时，是不是集群能提高并发量，我就用webbench做了如下测试，结果如下：

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webbench -c 500 -t 30 http://192.168.88.152/test/nginx-test.jsp

 

结果：

Webbench - Simple Web Benchmark 1.5

Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

 

Benchmarking: GET http://192.168.88.152/test/nginx-test.jsp

500 clients, running 30 sec.

 

Speed=76976 pages/min, 1733260 bytes/sec.

Requests: 35411 susceed, 3077 failed.

 

 

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webbench -c 500 -t 30 http://192.168.88.152:8080/test/nginx-test.jsp

 

结果：

Webbench - Simple Web Benchmark 1.5

Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

 

Benchmarking: GET http://192.168.88.152:8080/test/nginx-test.jsp

500 clients, running 30 sec.

 

Speed=81846 pages/min, 1044932 bytes/sec.

Requests: 28120 susceed, 12803 failed

 

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webbench -c 500 -t 30 http://192.168.88.152/dxh/index.html

 

Webbench - Simple Web Benchmark 1.5

Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

 

Benchmarking: GET http://192.168.88.152/dxh/index.html

500 clients, running 30 sec.

 

Speed=8594 pages/min, 596364 bytes/sec.

Requests: 2500 susceed, 1797 failed.

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webbench -c 500 -t 30 http://192.168.88.152:8080/dxh/index.html

 

Webbench - Simple Web Benchmark 1.5

Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

 

Benchmarking: GET http://192.168.88.152:8080/dxh/index.html

500 clients, running 30 sec.

 

Speed=81470 pages/min, 11509763 bytes/sec.

Requests: 40735 susceed, 0 failed.

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我完全不明白了，为什么动态的jsp处理能力明显增强了，但加了缓存的squid反而不如一个tomcat的处理速度？我的squid的缓存确定是生效了，我用squid -z实现过。请各位给点明示！