Using Geo-Replication for setting up database level replication





On this opportunity we are demonstrating how to configure Azure SQL Database Geo-Replication. Geo-Replication is a business continuity/disaster recovery solution that provide asynchronous replication of committed transactions from a primary database to up to 4 active secondary (readable) replicas on the same region/datacenter or on a different region/datacenter.

SQL Azure databases already had local replicas on the same regional datacenter before Geo-replication, thus when transactions are committed to a primary SQL Azure database, they are replicated to 2-3 database replicas which are in sync at all times and, in case of local failures, automatic failover occurs to one of the local replicas.

Geo-Replication now allows replication outside the boundaries of a datacenter. Essentially Geo-Replication allows replication of the primary database on a regional datacenter to a another datacenter on another region, where a new database will be created based on the primary and the new database will be acting as an active secondary database, but that secondary database will have its 2-3 own local replicas on its own region too.



Benefits and advantages of Geo-Replication for SQL Azure databases .

- It provides database-level disaster recovery and is business continuity solution with very low recovery time.

- It brings protection of SQL Azure databases (and the applications that use them) of regional failures or against partial failures on regional datacenters.

- Geo-Replication provides redundancy of SQL Azure databases outside of regional boundaries.



- Applications are allowed to access the secondary database in read-only mode and use it for querying, reporting, analytics and heavy workloads while increasing performance of the primary database.

- It is not a premium offering anymore. It is available on the basic tier and the demonstration on this article shows that.

- The user decides to which datacenter/region he wants its database to be replicated.

- Up to 4 active secondary replicas are allowed to configure on Geo-replication.

- Failover from a primary database to a local secondary replicated database on the same datacenter continues to be automatic, but failover of the primary to an active secondary database on another region/datacenter can be done by a user or by an application.

- We have to pay for all active secondary replicas but do not have to pay for the traffic between the primary and the active secondary replicas.

- Geo-replication can be used to migrate SQL Azure database from one server to another with minimum downtime.



- Geo-replication can be configured on elastic pool databases.





