Nov 10, 2018

WHAT IS CORE DIFFERENCE PERCONA XTRADB CLUSTER FROM MYSQL REPLICATION ?

Let’s take look into the well known CAP theorem for Distributed systems. Characteristics of Distributed systems:
C - Consistency (all your data is consistent on all nodes),
A - Availability (your system is AVAILABLE to handle requests in case of failure of one or several nodes ),
P - Partitioning tolerance (in case of inter-node connection failure, each node is still available to handle requests).
CAP theorem says that each Distributed system can have only two out of these three.
MySQL replication has: Availability and Partitioning tolerance.
Percona XtraDB Cluster has: Consistency and Availability.
That is MySQL replication does not guarantee Consistency of your data, while Percona XtraDB Cluster provides data Consistency (but it loses Partitioning tolerance property).