Overview
Server groups and affinity policies enable you to control the placement of your instances across the infrastructure. By using these features, you can optimize for high availability, reduce resource contention, and enforce workload separation or colocation as needed.
Key Concepts
Server Groups
- Definition:
Server groups allow you to group multiple instances together based on shared scheduling policies. This grouping can influence where and how instances are placed. - Usage:
Ideal for workloads that require high availability or resource isolation. By grouping related instances, you can enforce policies that ensure they are either placed on the same host or spread across different hosts.
Affinity and Anti-Affinity
- Affinity:
Specifies that instances should be placed on the same host. This is useful when low-latency communication between instances is critical. - Anti-Affinity:
Ensures that instances are not co-located on the same host, which can improve fault tolerance and reduce the risk of simultaneous hardware failures.
How to Use Server Groups and Affinity Policies
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Creating a Server Group:
- Access your cloud panel and navigate to the server group management section.
- Define a new server group by specifying a name and choosing a policy (affinity or anti-affinity).
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Assigning Instances:
- When launching new instances, select the server group you wish to associate with the instance.
- The system will automatically schedule your instance according to the selected group’s policy.
-
Managing Policies:
- Monitor the placement and performance of instances within the server group.
- Adjust or recreate server groups if workload requirements change.
Best Practices
- High Availability:
Use anti-affinity policies for critical applications to avoid single points of failure. - Performance Optimization:
Use affinity policies when low-latency communication between tightly coupled instances is needed. - Documentation & Monitoring:
Keep records of your server group configurations and review placement outcomes to ensure that the policies are achieving the desired results. - Scaling:
Plan server group usage in your scaling strategy so that new instances automatically benefit from optimized placement policies.
