Learn how to accelerate PHP database operations by employing persistent connections, implementing a connection pool, and caching query results, with clear code examples for mysqli, PDO, and Memcached that illustrate each optimization technique and its impact on reducing latency and resource usage.
Explain that “keepalive” is a concept used in both NGINX and HTTP protocol but with different meanings. In HTTP, keep‑alive (or persistent connection) is a header that allows a TCP connection to be reused for multiple requests, reducing latency. In NGINX, keepalive refers to the connection‑pool settings for upstream servers, controlling how many persistent connections are kept and their timeout.
This comprehensive guide explains Linux Virtual Server (LVS) fundamentals, its general architecture, various load‑balancing modes (NAT, DR, TUN, FULL‑NAT), scheduling algorithms, persistent‑connection options, and provides step‑by‑step ipvsadm commands and scripts for deploying and managing LVS clusters on CentOS 7.
The article explains how modern browsers handle TCP connections and HTTP requests, covering persistent connections, the limits of HTTP/1.1 pipelining, the advantages of HTTP/2 multiplexing, and browser-imposed limits on simultaneous connections per host.
This article walks through the HTTP/1.1 keep‑alive model, shows how a simple Go program creates separate TCP connections for sequential requests, uses netstat and tcpdump to observe the behavior, and demonstrates how adjusting http.Client's transport settings enables true persistent connections even under concurrency.
The article investigates why a MySQL server shows a large number of TCP connections in TIME_WAIT state, examines OS and MySQL logs, tests sysctl adjustments, captures network packets to reveal short‑lived client connections, and concludes that using persistent connections can eliminate the issue.
