Comment by ezekg

21 days ago

Do you have any public docs on how y'all migrate customers out of Heroku Postgres without downtime?

Seems to be the sticking point for a lot of people, myself included.

hey!

northflank supports the same buildpacks that you run on Heroku, so it should be fairly straightforward.

we have these docs for a more detailed walkthrough:

1/ https://northflank.com/docs/v1/application/migrate-from-hero...

2/ https://northflank.com/blog/how-to-migrate-from-heroku-a-ste...

  • Looks like that still has downtime for a Postgres migration- you're suggesting going into maintenance mode and just doing a dump/restore. I've seen that take hours once you hit the terabyte scale, depending on hardware.

    I've had pretty good luck setting up logical replication from Heroku to the new provider and having a 10-15 minute maintenance window to catch up once it's in sync. Might be worth considering.

    You might also want to add a warning about Postgres versions. There's some old bugs around primary key hash functions that can cause corruption on a migration. I've seen it twice when migrating from Heroku to other vendors.

  • Sorry, but telling people to take a logical backup of their database, and then download it onto their local work station is insane for a production application. First, a logical backup at any decent scale will fail, and second, I don't even have enough local storage to do that -- even ignoring the compliance issues with downloading a full copy of production data onto a work station.

    For a company like Northflank, I'd expect actual production-grade documentation for migrating, not instructions that are only applicable to a toy app.

Crunchy Bridge will help you migrate. They did a great job for us. We had a minute or so of downtime to let the read replica catch up and cut across. The team knows Heroku well, and some of them built it. (No affiliation, just a happy customer.)