Container Application Migration with Data Copying

Solution Overview

Problem

Current methods for migrating stateful applications between clusters result in extensive downtime due to the need for data copying, which is inadequate for applications requiring high availability, as they often stop the application before data copying is complete, leading to inconsistent data and potential data loss.

Innovation Solution

The method involves starting data copying before stopping the application on the source cluster and keeping it running until the amount of uncopied data is sufficiently small, then flushing and replicating the data to the destination cluster, ensuring application consistency and reducing downtime by deploying the application only after complete data replication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If data copying is performed before stopping the application, then data consistency is improved, but migration time is extended

Engineering Contradiction:

Improvedata consistencyVSAvoidmigration time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary data copying from source to destination storage before stopping the application. The migration controller initiates data copy operations for all volumes associated with the application, ensuring data is replicated to the destination cluster before the application needs to be stopped, thus maintaining data consistency while optimizing migration timing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The migration controller continuously monitors data copy progress and determines when data copying is complete before proceeding to stop the application. This feedback mechanism ensures that the application is only stopped after data consistency is achieved, resolving the contradiction between maintaining data consistency and minimizing migration time

Inventive Principle:

Principle #23Feedback

2Productivity

If the application is stopped before data copying is complete, then migration speed is improved, but data consistency is compromised

Engineering Contradiction:

Improvemigration speedVSAvoiddata consistency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary data copying from source to destination storage before stopping the application. The migration controller initiates data copy operations for all volumes associated with the application, ensuring data is replicated to the destination cluster before the application needs to be stopped, thus maintaining data consistency while optimizing migration timing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The migration controller continuously monitors data copy progress and determines when data copying is complete before proceeding to stop the application. This feedback mechanism ensures that the application is only stopped after data consistency is achieved, resolving the contradiction between maintaining data consistency and minimizing migration time

Inventive Principle:

Principle #23Feedback

3Ease of operation

If the application remains running during data copying, then availability is maintained, but data consistency becomes difficult to ensure

Engineering Contradiction:

ImproveavailabilityVSAvoiddata consistency

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary data copying from source to destination storage before stopping the application. The migration controller initiates data copy operations for all volumes associated with the application, ensuring data is replicated to the destination cluster before the application needs to be stopped, thus maintaining data consistency while optimizing migration timing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The migration controller continuously monitors data copy progress and determines when data copying is complete before proceeding to stop the application. This feedback mechanism ensures that the application is only stopped after data consistency is achieved, resolving the contradiction between maintaining data consistency and minimizing migration time

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12159051B2Migration of application on container platform

Publication Date: 2024.12.03 HITACHI VANTARA LTD

AI summary

A method for application migrating from a first cluster to a second cluster. The method may include detecting application migration request from the first cluster to the second cluster for performing application migration; identifying first volumes associated with the first cluster that are used by the application; establishing data copying from the first volumes of a first storage device associated with the first cluster to second volumes of a second storage device associated with the second cluster; determining if a copy condition is met based on the data copying; for meeting the copy condition, stopping the application on the first cluster; flushing uncopied data from the first volumes to the second volumes; determining whether the flushing of the uncopied data is completed; and for the flushing of the uncopied data being completed, deploying the application on the second cluster.