Hosting and domains: how to migrate a website between hostings without downtime?
Migrating an internet project between different hosting providers without downtime for users and loss of search traffic is a complex technical task that requires clear planning and sequential execution of steps. When dealing with hosting and domain issues during migration, an extremely useful approach is to find the original source of information, such as official documentation, technical specifications, and release notes of the software being used. Reproducing potential problems on a minimal test example before starting a large-scale migration will help identify incompatibilities of PHP versions, databases, or server modules in advance.
The first stage of migration is the complete preparation of the new hosting account and the transfer of all site files. You connect to the old server via the SSH protocol or through an FTP client, archive the project's root directory, and download the archive to your local computer or directly to the new server. On the new hosting, you need to deploy a similar software environment, unpack the archive, and check the correctness of file and folder permission distribution so that the web server can work with them correctly.
The second stage involves transferring the site's database, which requires special care to avoid losing current information. On the old hosting, through the phpMyAdmin utility or the console, you create a complete database dump in SQL format. Then, on the new hosting, a new database and a user with the appropriate rights are created, after which the created dump is imported there. Following this, you need to edit the site's configuration files, specifying the new database credentials for the new server.
The third step involves thorough testing of the site on a temporary domain or via your computer's local hosts file. This method allows you to open the site from the new server before changing global DNS records, which makes it possible to check the functionality of all pages, feedback forms, user authorization, and scripts. Any errors discovered at this stage can be quickly fixed without worrying about the reaction of real visitors and search bots.
The fourth step is the actual process of domain switching and minimizing downtime, which is achieved by pre-reducing the TTL value in DNS settings to minimum values, for example, to three hundred seconds. After this, you change the IP addresses in your domain's A records to the IP address of the new hosting. Thanks to the low TTL, the global update of information among internet providers will happen as quickly as possible, and it is recommended to keep the old hosting active for a few more days to process requests from users whose providers update their cache slower than the rest.