Comment by JohnMakin
7 months ago
I've never done a migration at a scale like this, but I have seen infra at similar scale, and I can't imagine how difficult this will be in a 12 month period. How big are github's ops/dev teams? That seems like a really unrealistic target to me. I expect outages.
> I expect outages.
With Github's service record, that means there should be no observable difference between them doing the migration and them operating as usual.
In practice, I'd expect the majority of servers to go through a tool based lift and shift like Azure Migrate. That's what we're using to migrate around 6k state government servers to the cloud. Where there are opportunities for low hanging modernization, we'll take that route. Like migrating to SQL Managed Instances rather than pushing to SQL in a VM.
When I was on infrastructure at Adobe, similar migrations took around 8-9 months (e.g. expanding into Azure, modernizing our datacenters, switching to Kubernetes).
The quote says the effort is to move "completely".
I think there will probably be a long tail which will prevent that from happening so quickly.
(It also probably doesn't really matter... if their main goal is to scale using azure they really only need the stuff that will be scaling up to be there. They probably also want to be seen as eating their own dog food, which can reasonably be achieved without all of the long tail.)
Maybe. Tho I would expect the devops practices and automation effectiveness of github internal projects to be far above your average shop.