# DRHCREL05-BP01 Provision spare compute capacity following an N\+M model
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 Provision spare compute capacity following an N\+M availability model, where N is the required capacity and M is the spare capacity to accommodate server failures. Use features like Amazon EC2 Auto Scaling groups, shared storage services, and AWS Elastic Disaster Recovery for reliable recovery. 

 **Desired outcome:** Achieve high availability with sufficient spare capacity and seamless failover capabilities in hybrid environments while consistently meeting data residency requirements, even during hardware failures or maintenance events. 

 **Benefits of establishing this best practice:** The N\+M model improves availability and resilience by providing buffer capacity to handle unexpected server failures or maintenance events, minimizing downtime and maintaining consistent performance while meeting data residency requirements. 

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

## Implementation guidance
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 Use placement groups with a spread strategy to improve reliability across hardware components. Prepare for network, instances, compute, racks or data centers, and Availability Zone or Region failure modes, and adopt highly-available design. Implement redundant network paths, and map application dependencies to understand the impact of disconnect events. Provide sufficient network redundancy to meet your application's availability requirements.