At FOSDEM 2014 ProxySQL and MaxScale were both presented. Both are proxy that can help build sophisticated MariaDB/MySQL architectures.
But currently what is the most used proxy with MySQL? It is HAproxy. HAproxy is a level 4 proxy that has no knowledge of the MySQL protocol. Being low level makes it very fast but it cannot accomplish any advanced proxy task. In many case this is enough for pure load balancing. But it cannot handle filtering, routing, query rewriting. This requires to understand the MySQL protocol and to look at the query passing through the proxy.
ProxySQL and MaxScale contrary to HAproxy are level 7 proxies. This means that they both understand the MySQL network protocol and they have access to the query payload.
At FOSDEM ProxySQL was presented by its developer René Cannaò. ProxySQL has interesting features like a very efficient query cache, query rewriting capabilities and a request queuing mechanism when the backend is not available. ProxySQL use regex to do query filtering and rewriting. It does not provide full query parsing.
Maxscale was presented by two of its developers Massimiliano Pinto and Vilho Raatikka. MaxScale is a more ambitious project. It supports a modular architecture. The underlying concept of modules allows to extend the MaxScale proxy services. The current version implements Read Write splitting and Load Balancing. Internally MySQL queries go through a SQL parsing phase. This gives MaxScale great capability regarding queries routing.
Talking about proxy technology without talking about MySQL Proxy would not be complete. MySQL Proxy was mentioned during presentations. When MySQL Proxy was born it attracted a lot of users as it was a very promising technology. The extensibility capability through the LUA scripting language makes it a very flexible technology. MySQL proxy does not embed a SQL parser and basic tokenization was made through LUA language. Unfortunately MySQL Proxy stayed forever in alpha status with no more improvement and no visibility on its future.
So if you are interested in proxy technology and want to know more about MaxScale do not miss tomorrow webinar MariaDB Enterprise and MaxScale - why all the buzz? delivered by Ivan Zoratti.