Stable Cuckoo Filter Updates for Accurate Data Stream Membership

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Solution Overview

Problem

Current data synopsis structures, such as cuckoo filters and Bloom filters, face instability and intolerable membership testing errors when handling frequent updates in data streams, particularly in applications like caching, network measurement, and network security, where recent data is more critical than older data.

Innovation Solution

A stable cuckoo filter (SCF) is designed with novel update strategies like random update, insertion failure update, scanning, skip scanning, blocked design, and local time-sensitive update strategies to maintain recent data and evict stale elements, ensuring stable performance and low update overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If current data synopsis structures (cuckoo filters, Bloom filters) are used for data streams with frequent updates, then space efficiency is maintained, but performance stability deteriorates and membership testing errors become intolerable

Engineering Contradiction:
Improvespace efficiencyVSAvoidperformance stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The cuckoo filter is divided into multiple independent sub-filters (first sub-cuckoo filter, second sub-cuckoo filter, etc.), each handling a portion of the data stream. This segmentation allows the system to maintain space efficiency while improving reliability by distributing the update load across multiple smaller structures, preventing any single filter from becoming unstable during frequent updates.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between different sub-cuckoo filters based on update frequency and data recency. When updates are frequent, the system activates additional sub-filters to handle the load, and can evict older sub-filters when they become stale. This dynamic adaptation maintains performance stability while preserving space efficiency by only using the necessary number of sub-filters at any given time.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If data synopsis structures handle frequent updates in data streams, then adaptability to stream applications is improved, but membership testing accuracy deteriorates

Engineering Contradiction:
Improveadaptability to stream applicationsVSAvoidmembership testing accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by pre-configuring multiple sub-cuckoo filters with appropriate capacities and characteristics before data stream processing begins. When updates are detected, the system has pre-established structures ready to handle the load, maintaining accuracy by distributing elements across pre-prepared filters rather than forcing updates into an overloaded single filter.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Different sub-cuckoo filters are assigned different local qualities or characteristics based on their intended function. Some sub-filters may be optimized for recent data with higher accuracy requirements, while others handle older data with relaxed accuracy. This local differentiation allows the system to adapt to stream applications effectively while maintaining overall membership testing accuracy through the combined performance of specialized sub-filters.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If conventional Bloom filter variants are made adaptive to stream applications, then versatility is improved, but performance stability and error tolerance deteriorate

Engineering Contradiction:
Improveadaptability to stream applicationsVSAvoidperformance stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention merges multiple cuckoo filter instances into a unified stable cuckoo filter system that functions as a single adaptive structure. Each sub-cuckoo filter maintains its independence for efficient updates, but they are combined through coordinated management to provide stable, consistent membership testing across the entire system, achieving both adaptability and reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stable cuckoo filter system achieves universality by being able to handle multiple types of data stream operations (insertions, deletions, membership queries) across varying update frequencies and data patterns. The multi-sub-filter architecture provides a universal solution that adapts to different stream application requirements while maintaining stable performance and acceptable error rates across all scenarios.

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

Data Source

PatentUS11496117B1Stable cuckoo filter for data streams
Publication Date: 2022.11.08 NAT UNIV OF DEFENSE TECH
  • US11496117B1 patent drawing
  • US11496117B1 patent drawing
  • US11496117B1 patent drawing

AI summary

A method for updating a stable cuckoo filter used for membership testing of data streams, executed by a processor, is described. The method includes the steps of: performing a first hash on a first element to be inserted into the stable cuckoo filter to determine a first candidate bucket; performing a second hash on a fingerprint of the first element to determine a second candidate bucket; selecting a target candidate bucket from a group consisting of the first candidate bucket and the second candidate bucket; inserting the first element into the target candidate bucket; updating the stable cuckoo filter according to one or more of a random update strategy, an insertion failure update strategy, a scanning strategy, a skip scanning update strategy, a blocked design strategy and a local time-sensitive update strategy; and obtaining an updated stable cuckoo filter.