Maximum Uptime

Question

I need maximum uptime with best costing.

We are working on the DR (Disaster Recovery) strategy and need some guidance here.

• The most critical area for them is “Transactional Database” and we proposed Azure SQL Database here, which we feel will serve best here.

a. Automatic failover is the best option here but 1 hour read-only secondary would beat the purpose here

b. Would you propose any other option here with no/minimal downtime?

• Ultimately we want to go to them with overall options and then recommend the best possible option for them (please refer to the summary table below)

• Then provide the detailed documentation on recommended DR options

Answer 1

Azure SQL Database provides two different solutions to recover your data from disasters: Geo Restore and Geo Replication. You can compare these 2 options in terms of costs, data loss, and recovery time.

It seems you are interested on recovery time. Geo Restore will basically restore your database from backup files. The recovery time can be impacted by multiple factors: how large your database is, which service tier the database is restoring to, where the backup files are, how many databases you are trying to recover, how many people are trying to recovery their databases… The ERT for geo restore (estimated recovery time) is 12 hours. But for some cases, especially for very large databases, it could run longer than that. If you have geo replication configured, the failover usually takes less than 30 seconds.