在优化网站性能的时候，我们会发现有些站点的Enable Keep-Alive分数很低，如何调整设置呢？HTTP持久连接（英语：HTTP persistent connection，也称作HTTP keep-alive或HTTP connection reuse）是使用同一个TCP连接来发送和接收多个HTTP请求/应答，而不是为每一个新的请求/应答打开新的连接的方法。如何设置Keep-Alive呢？随ytkah一起来看看，以Apache为例
1、如果您无权访问Web服务器配置文件，则可以通过在.htaccess文件添加以下代码行来实现添加HTTP标头：
<ifModule mod_headers.c> Header set Connection keep-alive </ifModule>
2、如果您能够访问您的Apache配置文件，则可以通过在/ etc / httpd / conf /中找到的httpd.conf文件中的这3行更改来打开保持活动状态。
KeepAlive On MaxKeepAliveRequests 0 KeepAliveTimeout 100
当然您可以调整具体的参数，可参考https://www.giftofspeed.com/enable-keep-alive/
– KeepAlive: Set it to "KeepAlive on" to enable keep-alive. To disable it use "KeepAlive off".
– MaxKeepAliveRequests: Sets the maximum number of requests for every keep-alive connection. A good number to start with is 60 requests per connection.
– KeepAliveTimeout: Sets how long your server should wait for new requests from clients. The 15 second default is too high. Set it to 3 seconds to start with and gradually go up when it underperforms. Setting it to a lower amount of seconds results in less parallel connections which again results in less server load.
做性能优化的朋友可以试试