Metadata Management via Selective Journal Staging

Solution Overview

Problem

Current data mirroring systems face latency issues and timeout conditions due to the need for synchronous writing of metadata tracks, which can be time-consuming, especially in large volumes, leading to delays in establishing copy relationships.

Innovation Solution

A method that selectively omits synchronous writing of metadata tracks from cache by staging them into a journal if the tracks contain all ones or all zeros, allowing for asynchronous writing and reducing processing latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If synchronous writing of metadata tracks is performed to ensure data consistency, then reliability is improved, but processing time increases and productivity deteriorates

Engineering Contradiction:

Improvedata consistencyVSAvoidprocessing speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by differentiating the writing approach based on the content characteristics of each metadata track. Tracks containing all ones or all zeros are written asynchronously to improve performance, while tracks with mixed values are written synchronously to maintain consistency. This selective approach optimizes the trade-off between reliability and productivity by applying different quality levels to different parts of the metadata based on their specific characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the writing mode parameter from always synchronous to conditionally asynchronous based on the content analysis of metadata tracks. By analyzing the parameter of track content (all ones, all zeros, or mixed) and adjusting the writing mode accordingly, the system achieves both data consistency and improved processing speed, resolving the contradiction between reliability and productivity.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If synchronous writing of metadata tracks is performed, then data consistency is maintained, but latency increases and timeout conditions occur

Engineering Contradiction:

Improvemetadata consistencyVSAvoidprocessing latency

Core Design Contradiction:

Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent applies local quality by differentiating the writing approach based on the content characteristics of each metadata track. Tracks containing all ones or all zeros are written asynchronously to improve performance, while tracks with mixed values are written synchronously to maintain consistency. This selective approach optimizes the trade-off between reliability and productivity by applying different quality levels to different parts of the metadata based on their specific characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent performs preliminary action by analyzing the content of metadata tracks before writing them. By pre-evaluating whether a track contains all ones, all zeros, or mixed values, the system can determine the appropriate writing mode in advance, avoiding unnecessary synchronous writing operations and reducing processing latency while maintaining data consistency where required.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If all metadata tracks are written synchronously from cache, then data integrity is ensured, but device complexity and processing overhead increase

Engineering Contradiction:

Improvedata integrityVSAvoidprocessing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by differentiating the writing approach based on the content characteristics of each metadata track. Tracks containing all ones or all zeros are written asynchronously to improve performance, while tracks with mixed values are written synchronously to maintain consistency. This selective approach optimizes the trade-off between reliability and productivity by applying different quality levels to different parts of the metadata based on their specific characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the writing mode parameter from always synchronous to conditionally asynchronous based on the content analysis of metadata tracks. By analyzing the parameter of track content (all ones, all zeros, or mixed) and adjusting the writing mode accordingly, the system achieves both data consistency and improved processing speed, resolving the contradiction between reliability and productivity.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9471499B2Metadata management

Publication Date: 2016.10.18 GLOBALFOUNDRIES US INC

AI summary

In one embodiment, a copy relationship is established between a storage location at a first site and a storage location at a second site, in a manner which includes selectively either 1) synchronously writing a modified metadata track from a cache to data storage if the metadata track in cache is a mixture of ones and zeros, before staging from data storage into the cache, the next track of the sequence of tracks of metadata, or 2) instead of synchronously writing from cache the modified metadata track, entering a journal entry to protect the modified metadata track in cache if the metadata track in cache is one of all ones and all zeros, so that asynchronous writing of the modified metadata track from cache is substituted for synchronous writing from cache. Other aspects are described.