Hello everyone,
I’m currently working with a mid-sized enterprise that’s moving from an on-premises datacenter to Google Cloud. We’re especially keen on implementing a hybrid cloud computing model: keeping some legacy workloads on-premises while shifting other services to GCP’s public cloud. Our main goals:
Ensure minimal downtime during migration
Maintain consistent security, identity, and network policies across both environments
Optimize for cost and performance once the hybrid setup stabilizes
We’ve started by using Anthos to manage Kubernetes clusters across on-prem and GCP, and are exploring options like Migrate for Compute Engine for VM migrations. However, we’re running into a few design questions:
How do you set up a unified IAM and networking scheme so that identity and access feel the same whether a workload runs on-prem or in GCP?
What are recommended strategies for “bursting” compute from on-premises into GCP during peak load?
How do we effectively monitor and bill hybrid-cloud usage so we avoid surprise costs?
Would appreciate advice from anyone who has done this kind of hybrid cloud computing migration with Google Cloud, or pointers to sample architectures and pitfalls to avoid.
Thanks in advance!
Hello @Amelia_Hebrew,
That’s a huge question you’re asking. I’ve been working in both environments, from R&D migrating to GCP, to factories that don’t want to hear about cloud, tech places and startups that can’t do without it, while sometimes doing it really badly.
To me, the Cloud is the future but it’s a new paradigm. If you’re not doing edge computing or dealing with ultra-private data that you absolutely don’t want to share, there will always be a reason to go to the Cloud. To GCP? Maybe not. I would personally always prefer GCP but I do understand that someone wants to go with something else.
I think the best thing to do, which is unfortunately often overlooked, is: RTFM.
Google has tons of documentation to learn how their services work and what the best practices are. You may be interested in reading Google Cloud Well-Architected Framework and Google Cloud security best practices center.
Regarding your questions:
How do you set up a unified IAM and networking scheme so that identity and access feel the same whether a workload runs on-prem or in GCP?
You’re looking at Workload Identity Federation and Best practices for using Workload Identity Federation.
What are recommended strategies for “bursting” compute from on-premises into GCP during peak load?
How do we effectively monitor and bill hybrid-cloud usage so we avoid surprise costs?
Set budget alerts on GCP and keep an eye on the expenses. Use the GCP Pricing Calculator and always check the Pricing Per Product. For example, just today, I could have run a script that would have cost more than one million $ for one Python line. Always check the price, always forecast and remember that you pay as you go. Also, GCP billing takes some time to notify you how much you spend so if you’re not careful, you will end up with a billing bomb after 24-48 hours.
Cloud can be scary for that but if you’re careful, close to being paranoid, you will be safe. Cloud is more expensive when it comes to hourly costs but, in the long run, if you’re building event-based and scalable architecture/infrastructure, you will save tons of money.
My last recommendation is: Do not build a 1:1 replica of what you had/have on-premises.
Cloud is not for that. I’ve seen so many people screaming at Cloud for being more expensive while booting huge VPS running 24/7 for no use 90% of the time. This is not how Cloud is supposed to be used, at all.
That’s where GCP certification comes in as the best way to learn such things. I highly recommend reading the great Dan Sullivan’s books and Udemy courses to get into GCP.
Last but not least, ask questions like you did, that’s the best way to learn and help the community grow 
Hope this helps.