How to organize a backup server with up-to-date data?

Question

PHP

There is a project that uses nginx + php-fpm + mariadb + memcachedb
Due to some circumstances, it is necessary to implement uninterrupted operation of the project, if one server is not available, the second one with up-to-date databases must somehow be connected. Tell me if it is possible to implement this and where to dig?

Answer 1

1. nginx+php make spare servers. They can be kept enabled, removed from upstream, and reconnected (manually or automatically, as you wish) in case the main server breaks down. You can distribute the load on them through a balancer or LVS
2. Memcache -- Use https://github.com/twitter/twemproxy to set up several servers in a bunch
3. Mariadb did not work with it, but there is probably replication. Delatete replication and everything is ready.