Saturday, January 20, 2018
Term: High Availability
2 post(s)

SQL Server - AlwaysOn 2012 Vs. AlwaysOn 2014

By Saleem Hakani on 9/21/2014

AlwaysOn (Codename. Hadron ((High Availability Disaster Recovery Always On)) was introduced in SQL Server 2012. It’s one of the most powerful high availability technology introduced in SQL Server and is one of the compelling reasons to migrate to SQL Server 2012 that provides reliable, integrated, flexible and efficient high availability and disaster recovery solution. In brief, AlwaysOn availability groups enable HADR for multiple databases with the need of expensive SAN hardware and you can offload many tasks/operations like (Queries, Reporting, Backups, Maintenance, etc.) to the secondary replicas and Primary replica can be used for write purpose. Data is copied per log record from Primary to secondary servers either synchronously or asynchronously. 

AlwaysOn Comparison
High Availability

SQL Server - High Availability Options

By Saleem Hakani on 9/21/2014

Log shipping requires a primary server and a secondary server.  It works by creating a full database backup to a secondary server to back up the existed data in the primary server, and creating transaction logs with continuous updated data restoring from the primary to the secondary server.

Pro: Log shipping supports a delay parameter.  If you catch a database error within the delay interval, the secondary can be used to help recover the database from the error.

Con: Users have to recover the back-up server, in another word, to stop log shipping to be able to retrieve the data from the secondary server.

Database Mirroring
Disaster Recovery
High Availability
Log Shipping
SQL Article Tags
Copyright [2014] by SQLCOMMUNITY.COM