# MSFTREL02-BP02 Develop a strategic plan for quickly reinstating service availability during outages
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 Microsoft workloads require specialized disaster recovery strategies due to their unique architectural dependencies and state management requirements. SQL Server Always On Availability Groups, Active Directory domain controllers, Exchange Database Availability Groups, and Windows Failover Clusters each have specific recovery procedures that differ from generic cloud workload restoration, requiring tailored approaches for rapid service reinstatement. 

 **Desired outcome:** Implement a comprehensive service restoration strategy specifically designed for Microsoft workloads that includes automated recovery procedures for SQL Server Always On configurations, Active Directory hybrid scenarios, and Windows-based clustering services. This plan should use AWS Elastic Disaster Recovery (DRS) for block-level replication while addressing Microsoft-specific challenges such as cluster reformation, domain controller restoration, and application-consistent recovery. 

 **Common anti-patterns:** 
+  Treating Microsoft workloads as generic applications during DR planning, failing to account for Active Directory dependencies, SQL Server cluster requirements, or Windows-specific services that require specialized recovery procedures. 
+  Relying on AWS DRS replication alone without planning for Microsoft cluster reformation, resulting in standalone SQL Server instances instead of properly configured Always On Availability Groups at the DR site. 

 **Benefits of establishing this best practice:** 
+  Verifies that complex Microsoft services like SQL Server clusters and Active Directory maintain their intended architecture and functionality after disaster recovery events. 
+  Pre-planned procedures for reforming Windows Failover Clusters and reestablishing Always On Availability Groups minimize manual intervention and potential errors during critical recovery operations. 
+  Maintains integration between on-premises Active Directory and AWS-hosted domain controllers, preserving authentication services and trust relationships during outages. 

 **Level of risk exposed if this best practice is not established:** High 

## Implementation guidance
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 Develop Microsoft workload-specific disaster recovery procedures that address SQL Server Always On Availability Groups restoration using AWS DRS, Active Directory domain controller recovery with proper site configuration, and Windows Failover Cluster reformation at DR sites. 

 Implement AWS Backup for Active Directory System State backups and configure cross-region replication for critical Microsoft services. 

 Establish automated procedures for reestablishing trust relationships, cluster quorum, and application dependencies specific to Microsoft environments. 

### Implementation steps
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1.  Configure AWS Elastic Disaster Recovery (DRS) for SQL Server Always On primary nodes with plans for cluster reformation and secondary replica establishment at the DR site. 

1.  Implement Active Directory disaster recovery using AWS DRS for domain controllers combined with AWS Backup for System State backups, providing a proper site and subnet configuration for hybrid scenarios. 

1.  Establish Windows Failover Cluster recovery procedures including shared storage configuration using Amazon FSx for Windows File Server and cluster quorum reestablishment. 

1.  Create automated runbooks for Microsoft-specific recovery tasks including SQL Server Always On listener reconfiguration, Active Directory trust relationship validation, and Exchange Database Availability Group restoration. 

1.  Configure cross-Region backup strategies for Microsoft workloads using AWS Backup with application-consistent snapshots and coordinate with AWS DRS replication schedules. 

1.  Implement regular testing procedures that validate Microsoft service dependencies, cluster functionality, and hybrid Active Directory connectivity after DR scenarios. 

## Resources
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 **Related documents:** 
+  [Set up high availability for SQL Server at DR site using AWS Elastic Disaster Recovery](https://aws.amazon.com/blogs/modernizing-with-aws/set-up-high-availability-for-sql-server-at-dr-site-using-aws-elastic-disaster-recovery/) 
+  [Hybrid Active Directory disaster recovery solutions on AWS](https://aws.amazon.com/blogs/modernizing-with-aws/hybrid-active-directory-disaster-recovery-cyber-resiliency-and-high-availability-solutions-on-aws/) 
+  [Choose a high availability and disaster recovery solution](https://docs.aws.amazon.com/prescriptive-guidance/latest/optimize-costs-microsoft-workloads/sql-server-hadr.html)