windows

(Failover Cluster) failover cluster가 어떻게 failure를 인지하는지

아이셩짱셩 2025. 5. 9. 10:24
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In a failover cluster, the failover mechanism is the process by which workloads are automatically shifted from a failing node to a healthy node in the cluster. This ensures minimal disruption to services and maintains high availability. The mechanism involves monitoring the health of each node and, upon detecting a failure, transferring the workload to another node. 
 
Here's a more detailed explanation:
 

 

1. Monitoring and Detection:
  • Heartbeat:
    Each node in the cluster periodically sends a heartbeat signal to other nodes, indicating its health status. 
     
  • Monitoring Software:
    The cluster management software continuously monitors the status of each node and the resources it manages. 
     
  • Failure Detection:
    If a node fails to respond or its health status becomes critical, the monitoring software detects the failure. 
     
2. Failover Process:
  • Automatic Transfer:
    When a failure is detected, the cluster management software automatically transfers the workload (applications, services, data) from the failed node to a healthy node. 
     
  • Resource Relocation:
    This may involve relocating virtual machines, databases, file shares, and other resources to the new node. 
     
  • Network and Storage:
    Network and storage resources are also managed to ensure seamless continuity of service. 
     
3. Key Considerations:
  • Quorum:
    A quorum is a mechanism that ensures the cluster can make authoritative decisions, even in the event of node failures. It helps prevent split-brain scenarios where multiple nodes believe they are the primary. 
     
  • Shared Storage:
    Failover clusters typically rely on shared storage, allowing multiple nodes to access the same data. 
     
  • Data Replication:
    Data replication ensures that the latest data is available on the standby node, enabling seamless failover. 

 

 

https://learn.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/windows-server-failover-clustering-wsfc-with-sql-server?view=sql-server-ver16

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