Client zero-downtime-migration — Server and Domain Migration Without Losing Traffic
Role Solo DevOps / Sysadmin
Period 2026
Stack
Linux Nginx Apache PHP 8.2+ MySQL MariaDB WP-CLI rsync Let's Encrypt Cloudflare SPF/DKIM/DMARC WordPress OpenCart Laravel

zero-downtime-migration — Server and Domain Migration Without Losing Traffic

Overview

A seamless move of busy sites, online stores and company web services — WordPress, OpenCart, Laravel and custom systems — to a new server or VPS/VDS, or to a new primary domain (a rebrand, a switch to .ua or .com.ua). The engineering aim is zero downtime: the business keeps running, corporate mail keeps working, and search weight is kept without redirect loops.

Risks and how they are handled

Risk How it is handled
DNS changes take hours to a day to propagate, so part of the audience cannot reach the site and orders are lost The TTL is lowered to 300 s a day before release, a final delta sync is run, and only then are the A records switched
Serialized data breaks: WordPress options and meta fields store domains in serialized form, and a plain SQL REPLACE corrupts widgets, themes and plugin settings Serialization-aware tools — wp-cli search-replace, or custom scripts for OpenCart and Laravel
Redirect loops (ERR_TOO_MANY_REDIRECTS) when the protocol, www and the domain all change together One verified redirect configuration (.htaccess or Nginx) and a 301 map that keeps the old link structure
Mailboxes lose history or land in spam Mail moved with its history; MX, SPF, DKIM and DMARC records re-checked and validated

How it goes

Current production (A)
        │  rsync / SCP + mysqldump
        ▼
New server / staging (B)
  ├─ Nginx + PHP-FPM (OPcache) + MySQL / MariaDB
  ├─ safe domain replacement via WP-CLI / Search-Replace-DB
  ├─ SSL (Let's Encrypt / Cloudflare)
  └─ full test through a hosts-file entry
        │  TTL to 300 s + delta sync
        ▼
Smooth DNS switch — zero downtime
  1. Target environment and backups. A full cold backup of the source (file system and MySQL dump). The new server is tuned: Ubuntu 22.04 / 24.04, Nginx, PHP 8.2+, MariaDB / MySQL 8, memory limits, timeouts and OPcache.
  2. Database and URL replacement. The database moves with tools that respect serialization, and configuration files (wp-config.php, config.php, .env) get their paths corrected.
  3. Staging test without touching DNS. The whole site — cart, forms, admin panel and integrations — is checked through a local hosts entry pointing at the new IP.
  4. Switch and final delta. TTL lowered 24 hours ahead, the final delta (orders and files that appeared during testing) synced, the A records updated, the 301 map applied if the domain changed, and the mail records validated.

Related: opencart-catalog-migration, tilda-migration, site-security-cleanup.

Stack

Linux (Ubuntu / Debian) · Nginx · Apache · OpenLiteSpeed · PHP 8.2+ · MySQL 8 / MariaDB · Redis · Docker · rsync · WP-CLI · Search-Replace-DB · certbot (Let's Encrypt) · Cloudflare API · SPF / DKIM / DMARC