Databases and horizontal scaling

Jump to bottom Edit New page

Kartik edited this page Feb 16, 2018 · 1 revision

Relational databases are designed to run on a single server in order to maintain the integrity of the table mappings and avoid the problems of distributed computing
Today, the evolution of relational databases allows them to use more complex architectures, relying on a “master-slave” model in which the “slaves” are additional servers that can handle parallel processing and replicated data, or data that is “sharded” (divided and distributed among multiple servers, or hosts) to ease the workload on the master server.
For example, Oracle RAC is a “clustered” relational database that uses a cluster-aware file system, but there is still a shared disk subsystem underneath
In MySQL, “master” and “slave” are terms used in asynchronous replication.
A MySQL master is any machine running mysqld with the following properties:
- it has a unique server_id
- it has the binlog enabled
- it has at least one login with the permission grant REPLICATION SLAVE
A MySQL slave is any machine running mysqld with the following properties:
- it has a unique server_id
- it has been configured with CHANGE MASTER to login to a master server and request binlogs.