Introducing Disaster Recovery

Abstract

Learn about the different Sitecore disaster recovery services.

Disaster recovery allows an organization to maintain or quickly resume mission-critical functions following a disaster that requires manual intervention. The Sitecore Disaster Recovery (DR) service offers two DR service types: DR Basic (confirmation) and DR Managed (automatically). With these go two Infrastructure types: Cold Standby (minimum infrastructure) and Hot Standby (full replica):

  • DR Basic Cold Standby: reactive service. Recovery and failover process will start after the event and requires confirmation of the customer. This is a cost-effective service option with a longer Recovery Time Objective (RTO). The Basic Cold Standby DR service type provisions the minimum infrastructure required and is often used for non-critical applications or in case data only changes infrequently.

    Basic Cold Standby Disaster Recovery includes Geo-Replication. In the event of a disaster, fail over to the secondary region happens and the database with minimal downtime.

  • DR Managed Hot Standby: proactive service. Failback and failover process will start automatically. Provisions an entire replica of the primary site. This provides the shortest RTO interval.

Which recovery option works best for your requirements depends on whether you require a proactive or reactive initiation of failover and how quickly you want to be back online in case of and outage.

Note

For more detailed information on Sitecore's disaster recovery processes, please review the Disaster Recovery Policy document.

Use the following table as a reference to decide which recovery option works best for your requirements, consider:

  • How quickly your site would need to be back online in the event of an outage.

  • The recovery point objective (RPO).

  • The recovery time objective (RTO).

Specifications

DR Basic cold standby

DR Managed hot standby

Backup technologies

SQL Azure Read-Access Geo-Redundant Storage

Azure APIs.

SQL Azure Geo-Replication

Azure APIs

Recovery process

  1. Customer request/approval for failover

  2. Deploy

  3. Restore

  4. Failover

  5. Go live

  6. Customer validation

  1. Failover

  2. Go live

  3. Customer validation

Secondary environment state

Created on demand

Fully deployed exact replica of the primary environment and up and running

Recovery Point Objective (RPO)

SQL 1 day

WebApp 12 hours

SQL 5 seconds

WebApp 12 hours

Recovery Time Objective (RTO) - Technology only

4 hours

< 1 minute

Failback Time - Technology only

4 hours

10 minutes

Note

The technology RTO values depend on how long the system takes to restore the Sitecore platform. If manual steps are required involving the customer or partner, this may extend the effective RTO.

A typical Sitecore environment is comprised of five Azure resource types: App Services, Azure SQL, Application Insights, Azure Search/SOLR, Redis Cache. Sitecore ensures the sizes and instance counts for all of the resources are replicated to a secondary data center. However, only App Services and Azure SQL have their files/data backed up and restored. The other services do not have their data replicated because it is either transient or not required for successful restoration, specifically:

  • App Services – All files/data are backed up and restored.

  • Azure SQL – All files/data are backed up and restored.

  • Redis Cache – Data is not replicated because Redis Cache contains user session data that typically expires before a Sitecore site can be restored, therefore it is not included as part of the disaster recovery strategy.

  • Application Insights – Data is not replicated because Application Insights only contains health monitoring data and this is not required for the runtime of the Sitecore site.