Probabilistic Cache Promotion via Random Thresholds

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Solution Overview

Problem

Existing cache systems require significant storage and computing resources to determine which data to store for efficient access, as they rely on counters to predict frequently accessed data, leading to inefficiencies in data placement.

Innovation Solution

A probabilistic method is employed where a random value is generated based on a threshold value, dynamically determined from observed data access patterns, to decide whether to store a data record in a cache, increasing the likelihood of frequently accessed data being cached over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If counters are stored for each data item to determine frequently accessed data, then data placement accuracy is improved, but storage resource consumption increases

Engineering Contradiction:
Improvedata placement accuracyVSAvoidstorage resource consumption
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts the counting function from individual data items and implements it at the cache structure level. Instead of storing counters with each data item, the system uses cache line occupancy patterns and replacement policies (like LRU) to implicitly track and identify frequently accessed data, eliminating the need for explicit counter storage per data item.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cache structure is designed to serve multiple functions: it not only stores data but also implicitly tracks access patterns through its replacement policy and occupancy state. The cache controller uses existing cache metadata (valid bits, dirty bits, replacement algorithm state) to determine frequently accessed data without requiring separate counting mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If counters are maintained for each data item, then frequently accessed data identification is improved, but computing resource consumption increases

Engineering Contradiction:
Improvefrequently accessed data identificationVSAvoidcomputing resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The cache system serves its own monitoring function by using its existing operational mechanisms (access patterns, replacement policies) to identify frequently accessed data. The cache controller leverages the natural behavior of cache accesses and its built-in replacement algorithms to determine which data should be promoted, without requiring external counting infrastructure.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of actively counting accesses and then making placement decisions, the system inverts the approach by using the cache's natural replacement behavior and occupancy patterns to infer frequency information. The replacement policy itself becomes the measurement mechanism, identifying hot data through its interaction with the cache structure rather than through explicit counting.

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If cache size is increased to store more frequently accessed data, then data access efficiency is improved, but cost effectiveness decreases

Engineering Contradiction:
Improvedata access efficiencyVSAvoidcache size
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies different caching strategies to different data items based on their access patterns. Frequently accessed data (identified through the implicit counting mechanism) receives preferential treatment through promotion to higher cache levels or extended retention, while less frequently accessed data follows standard cache behavior. This localized optimization allows efficient use of limited cache resources.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cache promotion mechanism dynamically adjusts which data items are retained or promoted based on their observed access patterns. The system continuously monitors access frequency and adapts the cache contents accordingly, promoting hot data and allowing cold data to be evicted. This dynamic behavior allows the cache to optimize its contents over time without requiring a larger static capacity.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS9336155B2Statistical cache promotion
Publication Date: 2016.05.10 META PLATFORMS INC
  • US9336155B2 patent drawing
  • US9336155B2 patent drawing
  • US9336155B2 patent drawing

AI summary

Storing data in a cache is disclosed. It is determined that a data record is not stored in a cache. A random value is generated using a threshold value. It is determined whether to store the data record in the cache based at least in part on the generated random value.