PHP 7: Real World Application Development

HTTP persistent connection

In HTTP persistent connection, or HTTP keep-alive, a single TCP/IP connection is used for multiple requests or responses. It has a huge performance improvement over the normal connection as it uses only a single connection instead of opening and closing connections for each and every single request or response. Some of the benefits of the HTTP keep-alive are as follows:

• The load on the CPU and memory is reduced because fewer TCP connections are opened at a time, and no new connections are opened for subsequent requests and responses as these TCP connections are used for them.
• Reduces latency in subsequent requests after the TCP connection is established. When a TCP connection is to be established, a three-way handshake ...