Intelligent Garbage Collection Scheduling for Storage Systems

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Solution Overview

Problem

Current data backup systems with deduplication face inefficiencies in storage space reduction and performance degradation due to frequent garbage collection operations, which consume significant computing resources and I/O bandwidth, leading to unnecessary runs of garbage collection and potential storage capacity issues.

Innovation Solution

Implementing an intelligent garbage collection scheduling policy that predicts future capacity utilization using a linear regression algorithm to determine the optimal timing for running garbage collection, thereby reducing unnecessary operations and maintaining system performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If garbage collection is run frequently to reclaim dead space, then storage space utilization is improved, but system performance is degraded due to increased computing resources and I/O bandwidth consumption

Engineering Contradiction:
Improvestorage space utilizationVSAvoidsystem performance
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The system performs preliminary actions by tracking reference counts for segments and predicting future capacity utilization before running garbage collection. The reference count tracking is maintained continuously, and capacity predictions are made using linear regression algorithms, allowing the system to proactively schedule GC only when necessary based on predicted capacity thresholds, thereby avoiding unnecessary GC operations that would degrade performance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms through continuous monitoring of reference counts and capacity utilization trends. The linear regression algorithm analyzes historical data to predict future capacity, and the GC scheduler uses these predictions to make informed decisions about when to execute GC. This feedback loop ensures GC is triggered only when capacity thresholds are approached, optimizing the balance between space reclamation and performance maintenance.

Inventive Principle:
Principle #23Feedback

2Quantity of substance

If garbage collection is run weekly to reclaim dead space, then storage capacity is maintained, but computing resources and I/O bandwidth are consumed unnecessarily

Engineering Contradiction:
Improvestorage capacityVSAvoidcomputing resources consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The system performs self-service by autonomously tracking its own capacity utilization and making intelligent decisions about GC scheduling. The reference count tracking and linear regression capacity prediction are performed automatically by the system itself, eliminating the need for external monitoring or manual GC scheduling. This self-service approach optimizes resource consumption by triggering GC only when the system's own capacity thresholds are approached.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes parameters from fixed weekly GC scheduling to dynamic, condition-based scheduling. Instead of running GC at fixed intervals, the system monitors capacity utilization trends and triggers GC only when predicted capacity exceeds thresholds. This parameter change from time-based to condition-based scheduling significantly reduces unnecessary GC operations and associated computing resource consumption.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If garbage collection is run to free storage space, then dead space is reclaimed, but the operation takes days to complete and degrades system performance

Engineering Contradiction:
Improvestorage space reclamationVSAvoidGC operation duration
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The system performs preliminary tracking of reference counts and capacity trends continuously, so that when GC is triggered, the system already has a clear picture of which segments can be safely removed. This preliminary data collection and prediction allows the GC operation to be more targeted and efficient, reducing the overall time required by avoiding unnecessary scanning and processing of segments that won't be removed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system replaces the mechanical, time-based GC scheduling with an intelligent prediction-based approach. Instead of blindly executing GC at fixed intervals regardless of actual capacity needs, the system uses linear regression algorithms to predict future capacity and triggers GC only when necessary. This substitution of mechanical scheduling with intelligent prediction reduces both the frequency and duration of GC operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11675536B2Intelligent scheduling for garbage collection
Publication Date: 2023.06.13 EMC IP HLDG CO LLC
  • US11675536B2 patent drawing
  • US11675536B2 patent drawing
  • US11675536B2 patent drawing

AI summary

An intelligent method of scheduling garbage collection (GC) in a storage system. A GC scheduler obtains capacity utilization and ingest rate of the storage system and calculate therefrom a predicted capacity utilization. When the predicted capacity utilization reaches a threshold, the GC scheduler invokes GC, but otherwise skips GC until such time as predicted capacity utilization reaches the threshold. The ingest rage may be calculated by performing linear fit on past data ingest. The GC scheduler may calculate predicted capacity utilization periodically according to preset period. The GC scheduler may calculate the predicted capacity utilization to a future date beyond the next period. The future date may be at least as far as the next period plus total ingest time.