Key parameters/关键的测试点或者是关注点有下面的三个方面：

The performance is usually measured in terms of:

1. 可以服务的请求数/Number of requests that can be served per second (depending on the type of request, etc.);

2. 系统的响应时间/Latency response time in milliseconds for each new connection or request;

3. 系统的通吐量/Throughput in bytes per second (depending on file size, cached or not cached content, available network bandwidth, etc.).The measurements must be performed under a varying load of clients and requests per client.

Web Server Benchmarking Tools：

Apache JMeter        Load testing and performance measurement application
curl-loader               Performance testing tool
ApacheBench           Apache (and other web servers) benchmark tool
FunkLoad                 Web testing tool in the same spirit as Perl’s WWW::Mechanize

httperf                       HTTP load generator
Siege                         HTTP regression testing and benchmarking utility
OpenSTA                  distributed software testing architecture which can perform scripted HTTP and

HTTPS heavy load tests with performance measurements from Win32 platforms