ML Latency Trend Throttling for Dedup File System Stability

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Solution Overview

Problem

Deduplicated file systems face performance degradation and potential shutdown due to sudden spikes in client requests and underlying storage system latency issues, leading to service disruptions.

Innovation Solution

Implementing a machine learning-based client throttling mechanism that tracks storage latency trends, throttling clients when latency increases, and withholding throttling when latency decreases, to prevent queue build-ups and maintain system stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If clients continue to issue requests to the file system without flow control, then client productivity is maintained, but the storage system experiences performance degradation and potential shutdown

Engineering Contradiction:
Improveclient request throughputVSAvoidstorage system availability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system implements a feedback mechanism by monitoring storage system performance metrics (latency, queue depth, throughput) and using this information to dynamically adjust client request rates. The file system analyzes performance data and sends feedback signals to clients to throttle or encourage request submission, creating a closed-loop control system that balances productivity and reliability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The flow control mechanism is dynamic rather than static. The system continuously adapts client throttling levels based on real-time storage system conditions, adjusting the degree of request rate limitation as performance metrics change. This allows the system to respond to varying workloads and storage capacity conditions

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If the file system performs deduplication operations to reduce redundant data, then storage efficiency is improved, but processing time increases during high request volumes

Engineering Contradiction:
Improvestorage capacity utilizationVSAvoidrequest processing latency
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The system applies partial deduplication action by selectively performing deduplication operations based on current system conditions. During high load periods, the system may reduce the intensity or frequency of deduplication operations to maintain acceptable response times, while still achieving some level of redundancy reduction. This balances the benefit of storage efficiency against the cost of processing time

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If the storage system handles sudden spikes in demand from multiple tenants, then service coverage is improved, but infrastructure performance degrades

Engineering Contradiction:
Improvedemand handling capabilityVSAvoidstorage throughput
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The system takes preliminary anti-action by proactively implementing flow control measures before the storage system becomes overwhelmed. When performance metrics indicate approaching capacity limits, the system preemptively throttles client requests to prevent saturation, rather than waiting for complete system failure. This anticipatory approach maintains service coverage while preventing throughput collapse

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentUS11954533B2Using machine learning techniques to flow control clients in a deduplication file system
Publication Date: 2024.04.09 EMC IP HLDG CO LLC
  • US11954533B2 patent drawing
  • US11954533B2 patent drawing
  • US11954533B2 patent drawing

AI summary

Detecting a trend in latency for storage underlying a deduplicated file system includes generating a set of data points by recording when input/output (IO) requests were issued to the storage and recording time required to receive success responses from the storage. Least squares regression is performed on the data points to find a best-fit line through the data points. A slope of the best-fit line is calculated. A determination is made as to whether the slope is positive, a positive slope thereby indicating a trend of increasing latency of the storage. When the slope is determined to be positive, clients accessing the deduplicated file system are throttled.