Online Database Snapshot via State Transitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Creating a clean database snapshot without interrupting database access is challenging, as preventing transactions during the snapshot process causes delays, while allowing transactions results in a 'fuzzy' backup due to ongoing updates.
Innovation Solution
The database transitions through specific states, including a replicating and change-prevention state, where new changes are allowed during copying and then prevented, ensuring a clean snapshot by using a copy-before-split, write clone, or split-before-copy approach, maintaining database availability and preventing updates after the snapshot time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If transactions are prevented during the file copy process, then a clean file snapshot is achieved, but database availability and performance deteriorate due to unacceptable delays
Solution Approach 1:
The patent segments the database files into multiple copies (original copy and backup copy) that can be maintained simultaneously. The original copy continues to accept transactions while the backup copy is being created and updated, allowing the snapshot process to be divided into manageable phases without blocking user access.
Solution Approach 2:
The patent performs preliminary actions by creating the backup copy file structure and establishing the copying mechanism before the original files are fully copied. This preliminary setup allows the system to transition smoothly into the copying phase while maintaining database availability, rather than requiring a complete stop beforehand.
2Productivity
If transactions are allowed during the file copy process, then database availability is maintained, but the backup copy becomes fuzzy with changes made after the snapshot time
Solution Approach 1:
The patent introduces an intermediary mechanism (the backup copy file) that acts as a mediator between the original database files and the snapshot requirement. This intermediary allows changes to be directed to the original copy while simultaneously maintaining a synchronized backup, resolving the conflict between allowing transactions and maintaining snapshot cleanliness.
Solution Approach 2:
The patent uses continuous copying from the original database files to the backup copy during the snapshot process. This copying mechanism ensures that the backup copy reflects the database state at snapshot time while the original continues to accept changes, achieving both availability and snapshot cleanliness.
3Manufacturing precision
If the database is taken offline for backup creation, then a clean snapshot is guaranteed, but system downtime increases significantly
Solution Approach 1:
The patent maintains continuity of useful action by allowing the database to remain online and operational throughout the backup creation process. The copying operation proceeds in the background without interrupting user transactions, eliminating downtime while ensuring snapshot cleanliness through controlled change prevention on the backup copy.
Data Source
AI summary
Techniques are described herein for making a clean file snapshot of a target file. The techniques may be applied to a single target file, to a set of target files, or to an entire database The techniques involve transitioning the target file through a series of states. During each state, particular actions are performed and/or prevented. In the final state of each approach, a clean file snapshot of the target file exists. Transitioning through the states, only one of which does not allow new changes to be made to the target file, allows the database to remain online and available to a greater extent than is possible with an approach that prevents database changes for the duration of the clean file snapshot creation operation.