Update Manager Prevents Split Brain Data Corruption

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In shared data clusters, the 'split-brain' condition can lead to data corruption due to uncoordinated access and updates from multiple partitions, which existing solutions like quorum-disk and reservation-based protocols often fail to prevent effectively, especially in heterogeneous environments.

Innovation Solution

A system with an update manager that maintains a local persistent store for each node, verifies cluster membership, and redirects updates only to the shared storage if the node belongs to a quorum, preventing updates from non-quorum nodes from corrupting shared data by using a configurable quorum detection policy and asynchronous data transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple nodes form independent clusters in a split-brain condition, then each node can continue to access shared data independently, but data corruption occurs due to uncoordinated updates from multiple partitions

Engineering Contradiction:
Improvedata access continuityVSAvoiddata integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A quorum manager is introduced as an intermediary component that mediates between cluster nodes and shared storage devices. The quorum manager receives update requests from nodes, verifies their quorum status, and coordinates access to shared storage. This intermediary prevents direct uncoordinated access from multiple partitions, resolving the data integrity issue while maintaining access continuity through proper coordination.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the parameter of node authorization by dynamically determining quorum status based on the number of operational nodes. When a node's quorum status parameter changes from valid to invalid (or vice versa), its access rights to shared storage are automatically adjusted. This parameter-based control mechanism prevents unauthorized updates from partitioned nodes while allowing legitimate access.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If quorum-disk based protocols are used to prevent split-brain, then data corruption is avoided, but the solution is too strict for small clusters and prone to transient connectivity failures

Engineering Contradiction:
Improvedata integrityVSAvoidcluster availability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Instead of requiring complete quorum consensus for all operations (excessive action), the system applies partial quorum verification only when necessary - specifically when detecting potential split-brain conditions or contention scenarios. Normal operations proceed without strict quorum checks, maintaining ease of operation while preventing data corruption in critical situations.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The quorum requirement is made dynamic rather than static. The system adjusts quorum thresholds and verification strictness based on current cluster conditions, such as the number of operational nodes, detected partitions, and operation types. This dynamic approach avoids the rigidity of fixed quorum-disk protocols while maintaining data integrity when needed.

Inventive Principle:
Principle #15Dynamics

3Reliability

If reservation-based protocols are used, then coordinated access is achieved, but the solution requires identical storage protocol versions across all shared storage devices, which is impractical in heterogeneous environments

Engineering Contradiction:
Improveaccess coordinationVSAvoidstorage environment compatibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The quorum manager is designed as a universal coordination layer that works across heterogeneous storage devices with different protocol versions. Instead of requiring all storage devices to support the same reservation protocol version, the quorum manager implements a protocol-agnostic coordination mechanism that translates and manages reservations uniformly, enabling access coordination in diverse storage environments.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The quorum manager serves as an intermediary between cluster nodes and heterogeneous shared storage devices. It abstracts away the underlying storage protocol differences by implementing a unified reservation management layer that handles coordination requests regardless of the specific storage device protocol version, thus maintaining both coordination reliability and environment versatility.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If cluster membership verification is performed for every update request, then data consistency is maintained, but response time increases due to additional verification steps

Engineering Contradiction:
Improvedata consistencyVSAvoidupdate response time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Cluster membership verification and quorum status determination are performed in advance and cached, rather than being executed for every individual update request. The system pre-establishes quorum membership information and validates it periodically or on significant events, reducing the verification overhead during actual data update operations while maintaining data consistency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Full cluster membership verification is performed only partially or selectively - specifically when there are indications of potential issues such as detected partitions, failed nodes, or contention conditions. During normal stable operation, simplified or cached verification is used, reducing time loss while maintaining data consistency through targeted verification rather than exhaustive checking for every update.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS7739677B1System and method to prevent data corruption due to split brain in shared data clusters
Publication Date: 2010.06.15 COHESITY INC
  • US7739677B1 patent drawing
  • US7739677B1 patent drawing
  • US7739677B1 patent drawing

AI summary

A system and to prevent data corruption due to split brain in shared data clusters includes two or more nodes of a cluster, a shared storage device, and an update manager. The update manager may be configured to maintain a local persistent store corresponding to each node of the cluster. On receiving an update request directed to the shared storage device from a first node, the update manager may be configured to redirect the update to the local persistent store corresponding to the first node. The update manager may be further configured to verify a cluster membership status of the first node, and to transfer the contents of the update from the local persistent store to the shared storage device if the cluster membership verification succeeds.