Disaster Recovery Node Data Loss Detection During Switchover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Data loss can occur during site switchover in high-availability data storage systems due to network disruptions, leading to incomplete data sets and potential errors when the failover site begins processing without detecting the undelivered updates.
Innovation Solution
Implementing a system where the number of operations yet to be completed by a node is tracked and mirrored to its high-availability and disaster recovery partners, allowing for detection of missing operations and preventing data corruption by failing affected volumes until the missing data is remediated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If site switchover is performed during network disruption, then high availability is maintained, but data loss occurs due to incomplete replication
Solution Approach 1:
The patent applies preliminary action by tracking the number of operations yet to be completed before switchover occurs. The system proactively monitors replication status and prepares data consistency information in advance, allowing the DR site to detect potential data loss before it becomes a problem, thus resolving the contradiction between maintaining high availability and preventing data loss
Solution Approach 2:
The patent implements feedback by having the DR site compare the tracked operation count with its own replication status. This feedback mechanism allows the system to detect data loss conditions and trigger appropriate remediation actions, ensuring that high availability operations do not result in undetected data corruption
2Reliability
If operations are tracked and mirrored to DR partners, then data integrity is detected, but system complexity increases
Solution Approach 1:
The patent applies self-service by having each node autonomously track its own operation completion status and automatically mirror this information to its HA and DR partners. The system performs self-diagnosis and self-reporting of replication status without requiring external monitoring infrastructure, thus achieving data integrity detection with minimal additional complexity
Solution Approach 2:
The patent uses copying by replicating the operation tracking information to HA and DR partners. Instead of implementing complex inter-node communication protocols, the system simply copies the operation count data to partner nodes, where it is automatically compared against local replication status to detect data loss, achieving reliable integrity checking with simple copy-based architecture
Data Source
AI summary
Techniques for detecting data loss during site switchover are disclosed. An example method includes storing at NVRAM of a first node a plurality of operations of a second node, the first and second nodes being disaster recovery partners. The method also includes during a switchover from the second node to the first node, receiving an indication of a first number of operations yet to be completed. The method further includes comparing the first number to a second number of operations in the plurality of operations stored at the NVRAM of the first node. The method also includes in response to the comparing, determining whether at least one operation is missing from the plurality of operations stored in the NVRAM of the first node. The method further includes in response to determining that at least one operation is missing, failing at least one volume.