Cloud Migration — Assessment Factors

During the migration assessment phase, there are several factors to consider, which impact migration feasibility and strategy.

The goal of doing a migration assessment is to:

1. Figure out the feasibility of migrating an application to the cloud.
2. Understand the migration drivers
3. Migration strategy that can be used (infrastructure and data)
4. The resource requirements for the cloud
5. Understand application up-time and DR constraints
6. Identify business and operational risks

We describe a few critical assessment factors and their impacts below:

Compute

Assessment Factors

• Is the workload running on bare metal or a virtualization platform?
• Is the workload running on an x86 system?
• How many roles running in how many servers/VMs?
• Does the application use any custom hardware appliances?

Impact

Cloud platforms are predominantly based on x86 hardware. These answers help decide if the workloads are compatible with the target cloud platform.

Storage

Assessment Factors

• Is there a shared or clustered storage used by the application?
• Is there any NFS storage used by the application?
• Is the storage being provided by a SAN?

Impact

Features such as shared storage are not available on cloud platforms. This usually requires a workaround such as virtual NAS appliances.

Networking

Assessment Factors

• What firewalls are used for the workload?
• Does the workload use IP multicast or broadcast?
• How are the subnets designed?
• Does the application use Load balancers?

Impact

IP Multicast often used for media applications but not supported on cloud platforms. This is to keep the networking control plane simple and manageable.

Application

Assessment Factors

• What type of application is it (public facing, corporate, analytics, etc.)?
• Is the application in-house or purchased from a vendor (traditional COTS)?
• If purchased, does the application vendor have a SaaS offering (such as O365)?
• Is the application stateless or stateful (for web applications)?

Impact

Availability of SaaS alternatives impacts migration path. If an commercially available SaaS application provides a good alternative for an existing application, then the effort of migrating that application to the cloud can be avoided. For example, existing Microsoft Exchange deployments can be replaced with Office365 subscriptions, instead of migrating Exchange servers to the cloud.

Licenses

Assessment Factors

• Does the application use commercial or licensed software?
• If yes, are the licenses portable to cloud?
• Is there a managed version of the software on cloud?
• Is there an open source equivalent of the software on cloud?

Impact

Impacts choice between BYOL or Pay-As-You-Go versions and associated costs.

Security

Assessment Factors

• Does the application use HSMs or any other corporate key management solution?
• Is the application tied to the local MAC IDs of the underlying hardware?
• Does the application use a Active Directory, or a corporate or third party SSO service?
• Is data encrypted at rest? If yes, what mechanisms are used?
• Is data encrypted when being served to end user?
• Is data encrypted between servers within the application?
• Does the application need to comply to a regulatory standard such as PCI-DSS, GDPR, etc.?

Impact

Hardware appliances cannot be migrated to the cloud, whereas tight coupling between the application and underlying hardware may constrain the migration. If virtual appliances are not available to replace the on premises hardware, hybrid environment may be a good intermediate stage for the migration. In this case, the hardware components stay on-prem, while others are migrated.

Availability and Disaster Recovery

Assessment Factors

• Is the application designed for HA?
• What kind of uptime constraints does the workload have?
• What is the RTO and RPO for the application?

Impact

• Uptime constraints impact cloud architecture and migration strategy
• RTO and RPO impact DR planning and strategies

Application and Operations Support

Assessment Factors

• Are there any CI/CD or DevOps processes in place?
• Does the application have ongoing development support?
• Does the operations team have necessary cloud skills?

Impact

Dev support can support refactoring if app needs small modifications.

The combination of the above factors decide how an application is taken to the cloud. In future posts, we’ll talk about some migration paths such as lift-and-shift.

This blog is part of our ongoing cloud series. To find out how GlobalLogic can help in your cloud migration journey, please reach out to us at cloud@globallogic.com.