Overview The Skinny
When it comes to zero downtime, proxies are the first line components of a cluster.
In order to achieve High Availability (HA) for MySQL, MariaDB and Percona Server, a commonly deployed setup consists of configuring load balancers (hardware or software) on top of those proxies.
A Strong Architecture How is Maintenance Made Possible?
With this proxy + load balancer architecture, server maintenance is made possible on any of the proxy hosts, as follows:
- the proxy is stopped
- the load balancer detects the dead proxy and removes it from the pool
- new connection requests go to live proxies
The Problem What Happens to Existing Sessions?
But wait… even though new connections are re-routed correctly, what happens …[Read more]