Stream Window Migration With State Synchronization Markers

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

There is a need for an efficient method to migrate an adaptive window from one host to another in a stream processing system without causing data loss or duplication, which is critical for maintaining continuous throughput and minimizing downtime in mission-critical applications.

Innovation Solution

A migration method that synchronizes the window states of the first and second window operators by using synchronization markers or fixed window sizes to ensure consistency, allowing parallel processing and minimizing downtime while avoiding data loss or duplication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If window migration is performed without synchronization, then migration speed is improved, but data consistency deteriorates causing loss or duplication

Engineering Contradiction:

Improvemigration speedVSAvoiddata consistency

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent applies preliminary action by performing window state synchronization before completing the migration. The source window operator and target window operator exchange synchronization markers to align their window states before the migration is finalized, ensuring data consistency is established in advance to prevent loss or duplication during the migration process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses synchronization markers as an intermediary mechanism between the source and target window operators. These markers facilitate the coordination and synchronization of window states during migration, enabling reliable data transfer without requiring the migration to slow down significantly

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If window state synchronization is performed during migration, then data consistency is improved, but migration time increases

Engineering Contradiction:

Improvedata consistencyVSAvoidmigration time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent maintains continuity of useful action by allowing the window operators to continue processing data units during the synchronization process. The synchronization markers are exchanged and window states are aligned without completely halting the data processing flow, enabling migration to proceed with minimal interruption to the overall system operation

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The synchronization is performed as a preliminary action that is integrated into the migration workflow rather than as a separate post-migration step. By aligning window states during the migration process itself, the patent avoids adding significant extra time to the overall migration duration

Inventive Principle:

Principle #10Preliminary action

3Productivity

If parallel processing is enabled during migration, then throughput is improved, but complexity of coordination increases

Engineering Contradiction:

ImprovethroughputVSAvoidcoordination complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent uses synchronization markers as an intermediary to coordinate parallel processing between source and target window operators. These markers provide a simple mechanism for both operators to know when to process data units and when to wait for synchronization, reducing the coordination complexity despite enabling parallel operation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements feedback through the exchange of synchronization markers between source and target window operators. Each operator sends and receives markers that provide information about the current window state, enabling coordinated parallel processing decisions based on real-time feedback from the other operator

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP4685644A1Method and apparatus for migrating a window of a window operator in a stream processing system

Publication Date: 2026.01.28 NOKIA SOLUTIONS & NETWORKS OY

Figure 1~2
Figure 3~4
Figure 5

AI summary

A migration method is disclosed for migrating a first window of a first window operator (610) from a first host (H1) to a second host (H2). A reconfiguration manager is configured to initiate and manage a migration, comprising creating a second window operator (620) in the second host (H2) and the second window operator (620) having a second window associated with a second window state. The first and the second window operators are configured to receive a stream of data units, add the data units to the first and, respectively, the second window states, and trigger the first and, respectively, the second windows to process or discard the data units in the first and respectively the second window states. The method comprises synchronizing the first and the second window states so that the first and the second window states are consistent upon completion of the migration, wherein completion of the migration comprises starting processing data units by the second window operator and discarding data units by the first window operator.