Backed by one of the most trusted names in technology, Google Cloud Platform (GCP) continues to innovate its services and expand its user base along with its peers. GCP extends many avenues for migration for newcomers and those switching from a different provider. 

This blog is a basic reference for what a migration to GCP entails, including all the tools GCP provides to accomplish this task. It should give you a better idea about whether you’re prepared to take that step.

Why Migrate to Google Cloud?

The question of whether or not to migrate to GCP is less about whether it’s a good idea, but choosing between this platform and others like AWS and Azure. There’s really no wrong choice, though one of these choices might be better for your company.  

As one might presume, GCP’s architecture is the same one that Google uses to power their most well-known applications like Gmail, Drive, and Docs. This isn’t just an endorsement for the kinds of apps that can be hosted using their technology, but an indication of how well Google handles an incredibly high amount of traffic. 

Beyond the power of the platform, there are all the cost-saving and modernized conveniences you’d expect from Alphabet, Inc. Like Azure with Microsoft’s products, you can expect GCP to engage all of Google’s related applications more cohesively than third parties. Consider the usefulness of a company GMail account that integrates with Calendar, Drive, and your virtual machine instance, under one umbrella with high-level compatibility.

Different Types of GCP Migration

There are two different types of database migrations that work with GCP–continuous and one-time–with several variations of each. We will cover the main types first, and then express the more specific migration methods to support them.

• Continuous/Ongoing/Online Migration – Continuing, Ongoing, and Online migrations are different names for gradual migration methods that use a staggered approach to ease users into the new environment. Snapshots of the source database are taken as read/write actions continue on the original infrastructure. The company can then move over all privileges to the new system once they are ready instead of all at once, an ideal scenario for those who are new to the cloud or have operations that are dependent on availability.

• At-Once Migration – This is the opposite of the previous approach, where the application and related resources are put on hold from write actions while the migration is in process. The upside is that the new system is ready to go faster, at the cost of expected downtimes. The snapshot is of a single point in time of the user’s choosing, so there must also be more preparation for the migration completed before it begins. 

Note that these two methods only pertain to the database behind the application (e.g. AlloyDB). Below are examples of GCP migrations that consider the entire infrastructure:

• Lift and Shift – This migration ‘lifts’ the source workload as close to its original state as possible, with minor modifications to the application and refactoring making up the ‘shifts’. The object of lift and shift is more about making sure the new system works than improving it with cloud technology. Companies that cannot refactor due to technical restrictions may be forced to perform this type of migration. Note that this type of migration does not prevent users from upgrading the shifted resources later.
• Improve and Move – Refactoring and modifications become more prominent in this method, filling in gaps where the legacy system lacks or needs updating and leveraging cloud technology to improve it.  
• Replacement – Replacing the application and all its surrounding structure to rebuild the workload is also possible during a migration. Obviously, this is the most involved method, and the most costly considering the amount of time it consumes. Still, rebuilding is an easier pill to swallow for companies working with an outdated legacy system that must upgrade with cloud technology to keep pace.

This document is just a glimpse into the many avenues Google provides to GCP. We recommend checking their getting started page for updates about migration tools, as new ones are released quite regularly.