Zero downtime migrations at Petabyte scale

Re:Zero downtime migrations at Petabyte scale by joshuamorton on Sunday February 22, 2026 @09:02PM (#47117148)

The code is open source though, you can read it. The cli examples point you towards the relevant bits of the actual database code to read.

For my own sake, I'm not sure what is so surprising here. "Turn up a hot second replica and fail over to it intentionally behind a global load balancer." Is pretty well trodden ground.

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Re:Zero downtime migrations at Petabyte scale by Snelius on Sunday February 22, 2026 @09:58PM (#47117527)

> The code is open source though, you can read it

Thank you! :D

> Is pretty well trodden ground.

YES!! But the article point us to it's a 400TB+ w/o downtime migration. This is impossible. That why is looks like clickbait and advertising of a product.

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Re:Zero downtime migrations at Petabyte scale by joshuamorton on Sunday February 22, 2026 @10:41PM (#47117820)

I will simply point out that I'm aware of larger zero down-time migrations, like this one: https://www.youtube.com/watch?v=ih97gwNmkRA

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Re:Zero downtime migrations at Petabyte scale by Snelius on Monday February 23, 2026 @09:19PM (#47132063)

Thank you for the link but it's not the same case ;) Google used storage switching which has migration in mixed mode, i.e. migration on demand when data migrated due user access to. API had compatibility layer to read/write from/to both storage systems (i built kind of this migration mechanism about decade ago). And google spend about 8 years for the migration which ok. And the article about Database migration which can be periodical process (critical scheme changes for example) and they describe it to us. Take snapshot and racing with snapshot overhead changes and etc. I think we can let's over here. It's not a zero downtime solution cuz it's not exists.

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