I’m thinking about moving Quirrel (a SaaS that provides a job queueing solution to serverless) to Fly.
Naturally, I want to make the transition as smooth as possible, ideally with near-zero downtime.
It currently runs on Heroku and Heroku Redis, and I want to move it to Fly and Lambda Store.
This is my current plan of action:
set up Fly x Lambda Store
put Heroku deployment into maintenance mode
migrate the database
point DNS entries to Fly
reenable Heroku deployment, this time as a reverse proxy to the Fly deployment
after all DNS caches point to Fly: Shut down Heroku
As this is the first migration I’m doing, I’d love to hear what you think about this. Does it make sense? Which experiences did you have regarding migrations? Any tips & tricks?
That migration looks right, though a lot can go wrong migrating hosting providers or DBs, so I’d split the work into 2 less risky phases:
Move app to fly - first get your app running on fly connecting to redis on Heroku. Once it’s ready, change DNS to fly so both are serving traffic, then scale Heroku down once all traffic is going to fly. It helps to change your DNS TTL to ~60s a few days before the migration to speed propagation.
move DB to Lambda Store - put your app into maintenance mode (we don’t have this built in, but you can have your app serve 503s or whatever you need), migrate the DB, then point to the new DB.
You can do those in either order, just practice beforehand
Also, you can now run redis or keydb clusters on fly using the persistent storage and private networking features we just launched. Might be cheaper and give more control than Lambda Store, but I’m biased
