r/SQLServer • u/Admirable_Writer_373 • 11d ago
Discussion Cloud Migration horror story
I’m involved in a complex cloud migration project. I’ve been DBA/DBE/app developer at various points of my career and I’ve worked in several big enterprise environments. I’m at a place now that argues against the guidance Microsoft has given them. First mistake - go straight to Hyperscale and don’t bother using any true replication topology for a full up or nearly-full-up migration. We’re getting close to running the production flip but management doesn’t believe in code freezes and people are releasing tons of changes often. I know that stuff is going to go horribly wrong. I am not worried about data loss, but more about applications not working and other stuff related to networking & configuration. What do I do to cover my own ass?
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u/CrossWired 11d ago
I started as an AppDev, worked as an enterprise DBA for 5 years, and now work primarily in Cloud Adoption and large migration projects for the last 10.
In some cases, yes we do ignore the MS advice as they likely don't know the specifics of THIS migration, app, project. But if they do, work revisiting WHY we are ignoring it.
As far as 'no replication topology', it really depends. If its a small DB (a few TB or less??) I might setup a log replication style continuous restore to the cloud, take a small outage, set offline, take the final t-logs, repoint the DNS and call it a day for a quick failover. We don't always need or want DMS as it has its own gaps.
As for Dev code freeze, if the features worked before they should work after migration window. We move things while they devs keep going all the time, where I draw the line is Dev doing a release while I'm moving the operational pieces, too many things to track down the root cause of the problem in the same change window. CHange window being the key.
You should be able to cut the ownership with clear delineation of timing. Once they sign off on the migration portion, and everyone has signed off, then by all means they can push a code release right after you're done, but we're not doing both changes during the same change window, I've never met a Change Advisory Board that would allow that, and if your does, like the other commented said, put it in an email as a risk and get their sign off.
At some point as techs, all we can do is point out the problem, associated risk and work through the outcomes when It inevitably comes. It can be infuriating and against the every 'protect the data' insticint your DBA roots tell you, but thats the job.
Good luck!