Confidential
Thank you Nik
That’s very useful and will be checking out the migration test tool!
Z
From: Nikolay Samokhvalov <samokhva...@gmail.com>
Sent: 22 May 2021 13:32
To: Zahir Lalani <ZahirLalani@oliver.agency>
Cc: pgsql-general@lists.postgresql.org
Subject: Re: Framework for 0 downtime deploys
No silver bullets exist (yet). A couple of things I can recommend:
1. GitLab's experience of changing schema without downtime and maintaining
backward compatibility – they have open documentation and a lot of things
solved and documented
- start here:
https://docs.gitlab.com/ee/development/migration_style_guide.html
- check their migration_helpers.rb, plenty of useful things there
2. What my team and I are doing with respect to database migration testing:
https://postgres.ai/. We created Database Lab Engine, an open-source tool to
clone databases of any size in seconds and test, manually or automatically in
CI, anything you want using "full-size" databases. It can help you catch and
block dangerous changes leading to downtime, as well as (if you have a
well-maintained set of tests for CI) enforce the backward compability.
Nik
On Sat, May 22, 2021 at 2:12 PM Zahir Lalani
<ZahirLalani@oliver.agency<mailto:ZahirLalani@oliver.agency>> wrote:
Confidential
Hello All
I wonder if I could garner some of the wealth of experience on this group:
Our current application deployments (every 3 weeks) require about 30min
downtime. We are now tasked of making this 0 downtime.
From all the reading I have done, we have solutions for the infrastructure and
code deploy, but with regards to the DB the main issue seems to be keeping the
new deploy backwards compatible – functions/tables/fields – all of it.
That seems like quite a large management task and would require careful reviews
of changes. Is there any type of framework that already manages this type of
capability? Or are there aspects of PG that we should be using in this regard?
Thx
Z
