Enabler #3 - A Prescriptive Migration Plan with Attention to Details
Once an application analysis determines the application is suitable for migra-
tion, and its migration patterns are known, you need to develop a detailed
migration plan. Besides the overall goal of the migration, a migration plan should
include execution level details, including all migration tasks and owners.
The execution level details will vary based on the chosen migration pattern. For
example, a Rehost pattern will mainly have infrastructure tasks with few appli-
cation configuration changes, as well as a test and validation plan. A Refactor
pattern migration effort will need to include details on each of the components
to be changed, including its current and future state, functionality, accompany-
ing code, deployment details, and test and validation plans.
At a minimum, the migration plan should include the following:
• Business drivers and expectations
• Functionality
• Current and future state architecture
• Patterns and approach
• Asset list, dependencies
• Desired configuration or changes
• Tools (migration, deployment, monitoring, logging)
• Detailed migration tasks, deployment plans with RACI
• Readiness, test, validation, cutover and operations plans
For migration efforts to achieve the desired velocity and scale, the migration
plan for execution needs to be very prescriptive. In addition, reusable approaches
and artifacts and self-service approaches for different stakeholders will greatly
help reduce latency.
In the process of creating a detailed migration plan, one should account for
approaches that reduce the amount of downtime required for cutover during a
migration effort. You can use various approaches to achieve close to zero down-
time for an application migration, including: blue/green deployments, incre-
mental replication, isolated environment for testing and validation before
cutover, or temporary DNS records for testing.
For example, you can develop standard migration checklists for each of the pat-
terns, which you can reuse across all applications. As many organizations have a
common set of tools for testing and validation, a common set of tests across pat-
terns is useful to the operations team for onboarding applications at the desired
velocity.
20 | THE DOPPLER | SPRING 2018