is your strategy ready for cloud migration ..?

This article articulate the web apps migration from on premise to cloud platform. To understand this article you should be aware of the cloud technology and Web app development platforms

There are 2 type of migration

1. Infrastructure migration

Infra migration involves replicating the on premise infra on the cloud. which involves server sizing, network parameters etc. Once the infra is created moved the application on the cloud platform

2. Application migration

We will try to migrate the application from the on premise to

Typicallycloud migration will have 3 phases,

1. Assess
2. Migrate
3. Optimise

1. Assess

This phase will help in making the decision for the migration with the right fitment in the cloud

1.1 Discovery

Discovery includes the portfolio analysis, where you will build the inventory of on premise application and its infra component.

During this phase, architect walk through the each application and record its application dependency like session management, framework version, software requirements etc, infra details like network, firewall, server details,database information includes the DB size, version of DB server etc

We divide the Application into Simple, Medium and High based on the complexity of the application.

Simple application can be refactored to cloud native, where are medium and high complex need to be migrated as IaaS

1.2 Map Application and infra components

From your discovery phase, we need to map the services and servers which can be compatible with the on premise application. This mapping activity will help us in minimizing the actual migration risk.

There are certain tools are available in Azure, which will help you in mapping the right infra on Azure

• MAP (Microsoft Assessment and planning tool kit)
• ASR (Azure Site Recovery)
• IO meter

1.3 Evaluate

After mapping the right infra and service component, we can evaluate the

• Migration path
• ROI
• TCO
• Timelines for migration
• Efforts requried for migration
• Developed skill set required for the migration

2. Migrate

In this phase we start the actual migration work, this phase will have 4 scenario

2.1 Rehost

If the on premise application/database has the complex infra and application dependency then host the application in the cloud infra. To consume the on premise service for the hosted cloud service app then make the site to site tunneling.

Re-hosting of the application in the cloud is simple and quick process.

2.2 Refactor

With the minimum changes to the application and DB, if it can be made as cloud native app and DB.

In this phase we can consider the application which requires the minimum changes to make cloud native by changing the Authentication, Logging framework, email services and 3rd party integration.

There are different option and tools are available for the DB migration to move the data from the on-premise to SQL Azure

• DMS
• Azure data factory
• Managed instances

There is good amount cost saving involved and less maintenance involve when we move the app and DB to azure PaaS solution

2.3 Re-architect

If the application need to use the cloud native feature like Auto scale, Server less architecture, infra orchestration etc, we need to re-acrchitect the solution.

Re-architecture approach might involves you considering the several factors in terms the technical fitment, sizing, costing, security and performance of the application

Conclusion

App migration to cloud should be process driven, evaluating the feasibility and compatibility of the solution at the each stage of the process.