In-Place Policy Updates via Ordered-Shifting

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Solution Overview

Problem

Existing methods for updating policies on network devices often require significant memory resources and disrupt active policies, leading to inefficient utilization of limited memory and prolonged disruption windows.

Innovation Solution

A method and system for performing in-place policy updates on network devices by receiving a class modification batch, generating an operation commit sequence, and committing updates using a policy update programmer to minimize memory usage and disruption time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If make-before-break methodology is used for policy updates, then policy disruption is minimized, but memory resources are inefficiently utilized

Engineering Contradiction:
Improvepolicy disruption minimizationVSAvoidmemory resource utilization
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the policy update process into distinct phases: parsing the batch, validating memory sufficiency, generating a target class sequence, creating an operation commit sequence, and executing updates. This segmentation allows the system to reserve memory only for the duration of the update operation rather than maintaining duplicate policy sets, thus improving memory utilization while maintaining reliability through phased execution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary actions by first parsing the batch, validating memory sufficiency, and generating the target class sequence before executing the actual policy updates. This preliminary processing allows the system to plan the update sequence and reserve memory efficiently, avoiding the need for continuous memory reservation during the update process.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If make-before-break methodology is used for policy updates, then policy disruption is minimized, but update speed is reduced

Engineering Contradiction:
Improvepolicy disruption minimizationVSAvoidupdate speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic memory reservation based on the actual update requirements. Instead of reserving a fixed, substantial portion of memory, the system dynamically allocates memory based on the batch size and update operations. This dynamic approach enables faster updates by reducing memory reservation time and overhead, while maintaining policy disruption minimization through controlled update sequencing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of memory reservation from a static, substantial portion to a dynamic allocation based on operational needs. By adjusting memory allocation parameters according to the actual update requirements, the system achieves faster update speeds while maintaining reliability through controlled policy application sequencing.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If substantial memory resources are reserved for policy updates, then update reliability is improved, but available memory for other functions is reduced

Engineering Contradiction:
Improveupdate reliabilityVSAvoidavailable memory for other functions
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts the memory reservation requirement from the general memory pool and ties it specifically to the update operation duration. By extracting the memory reservation to only when needed during the update process rather than maintaining it continuously, the system improves availability of memory for other functions while maintaining update reliability through targeted memory allocation during the update phases.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements a memory recovery mechanism where the reserved memory is released after the update operation completes. This discard and recover approach ensures that memory is not permanently consumed by update operations, thereby maintaining availability for other network functions while ensuring update reliability during the operation window.

Inventive Principle:
Principle #34Discarding and recovering

Data Source

PatentUS11050627B2Method and network device for enabling in-place policy updates
Publication Date: 2021.06.29 ARISTA NETWORKS INC
  • US11050627B2 patent drawing
  • US11050627B2 patent drawing
  • US11050627B2 patent drawing

AI summary

A method and network device for enabling in-place policy updates. Specifically, the method and network device disclosed herein entail effecting the removal and/or insertion of policies on the network device while minimizing a window in which active policies may be disrupted by the policy updates. Further, in-place policy updates call upon the ordered-shifting of content stored across data structure elements. Through ordered-shifting, policy updates can utilize limited memory resources, on the network device, more efficiently over existing methodologies. Additionally, policy updates can also be committed faster, thereby allowing more policy updates to be processed with a fixed time window.