今天给lamp一键安装包增加了一个扩展-varnish，主要作为wordpress博客的缓存。下面我们来用ab工具做一个简单的并发为100，连接数为1000的压力测试，一个是没有启用varnish缓存的，一个是varnish前面缓存的。
服务器参数：系统centos 5 32位，单核，Intel(R) Xeon(R) CPU L5630 @ 2.13GHz，1G内存
没有经过varnish缓存的测试结果：
负载40.44
Concurrency Level: 100
Time taken for tests: 305.766 seconds
Complete requests: 1000
Failed requests: 1
(Connect: 0, Receive: 0, Length: 1, Exceptions: 0)
Write errors: 0
Non-2xx responses: 1
Total transferred: 19746015 bytes
HTML transferred: 19521638 bytes
Requests per second: 3.27 [#/sec] (mean)
Time per request: 30576.620 [ms] (mean)
Time per request: 305.766 [ms] (mean, across all concurrent requests)
Transfer rate: 63.07 [Kbytes/sec] received
开启了varnish前端缓存的
负载0.05
Concurrency Level: 100
Time taken for tests: 12.720 seconds
Complete requests: 1000
Failed requests: 0
Write errors: 0
Total transferred: 20086736 bytes
HTML transferred: 19821261 bytes
Requests per second: 78.62 [#/sec] (mean)
Time per request: 1271.991 [ms] (mean)
Time per request: 12.720 [ms] (mean, across all concurrent requests)
Transfer rate: 1542.15 [Kbytes/sec] received
这两组数据不用我说，你也应该明白了。