Snapshot Processing for Active-Active Storage Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In active-active data center setups, taking snapshots across long-distance sites leads to concurrent I/O interfaces at two locations, causing synchronization issues and long latency, which affects application services and reduces snapshot rates due to the need for blocking or suspending I/O interfaces.
Innovation Solution
A snapshot processing method that allows I/O interfaces to remain active by setting a preparation state for snapshot processing on both primary and mirror storage devices, ensuring data consistency without blocking or suspending I/O operations, and improving snapshot operation rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If I/O interfaces are blocked or suspended during snapshot processing, then data consistency between primary and mirror storage devices is ensured, but application services are affected and snapshot rate is reduced
Solution Approach 1:
The patent applies preliminary action by pre-allocating snapshot storage resources and preparing the snapshot taking environment before actual snapshot operations. The system pre-establishes the snapshot storage space on mirror storage devices and prepares the data replication mechanism in advance, so that when a snapshot is needed, the I/O interfaces can remain active while the pre-prepared resources handle the snapshot creation without blocking user operations.
2Reliability
If I/O interfaces are blocked or suspended during snapshot processing, then data consistency between primary and mirror storage devices is ensured, but service interruption time increases
Solution Approach 1:
The patent implements continuity of useful action by enabling I/O operations to continue uninterrupted during snapshot processing. The system maintains active I/O interfaces that allow continuous data writing and reading operations while simultaneously performing snapshot creation in the background using pre-prepared resources and asynchronous data replication mechanisms.
3Reliability
If snapshots are taken at long-distance cross-site locations with concurrent I/O interfaces, then data replication is achieved, but synchronization latency increases
Solution Approach 1:
The patent applies preliminary action by pre-establishing snapshot storage spaces on mirror storage devices at remote locations and pre-configuring the data replication infrastructure. This preparation is done before actual snapshot operations, so that when snapshots need to be created at long-distance cross-site locations, the system can immediately begin asynchronous data replication without waiting for resource allocation or setup, thereby reducing synchronization latency.
4Productivity
If snapshots are taken with active I/O interfaces, then snapshot rate is improved and service continuity is maintained, but data consistency between primary and mirror storage devices becomes challenging
Solution Approach 1:
The patent uses an intermediary mechanism by introducing a snapshot management system that coordinates between primary and mirror storage devices. This intermediary manages the snapshot creation process by controlling data replication, handling consistency protocols, and coordinating the activities of distributed storage systems, thereby maintaining data consistency even while I/O interfaces remain active and concurrent operations occur.
Data Source
AI summary
A snapshot processing method includes: receiving a snapshot request command, where the snapshot request command includes an ID of a primary LUN; determining the primary LUN according to the ID of the primary LUN, and setting a snapshot status of the primary LUN to a preparation state; sending a first snapshot command to a mirror storage device, where the first snapshot command includes the ID of the primary LUN, and the first snapshot command is used to notify the mirror storage device that the primary LUN is in the preparation state; receiving a response message, sent by the mirror storage device, of the first snapshot command, where the response message is used to notify the primary storage device that a mirrored LUN is in the preparation state; and performing snapshot processing on the primary LUN.