I would like to upgrade 4 environments.
each of these records about 90 million page views per month.
I would obviously start with a validation environment with minimal traffic.
what upgrade strategy do you recommend?
go by steps?
from 3.14.1 to 4.0.0, 4.1.0… 4.12.3?
In my opinion, the way I would follow if I were at your place would be:
Backup DB
Upgrade to the latest 3 version (seems to be 3.14.1). Be careful: migrate also plugins to the latest versions compatible with Matomo 3! Be also careful, because of the huge volume of data you have, the database migration may take long time…
Test
Backup DB
Upgrade to the first 4 stable version (seems to be 4.0.5). Be careful: migrate also plugins to versions compatible with Matomo 4.0! Be also careful, because of the huge volume of data you have, the database migration may take long time…
Test
Backup DB
Upgrade to the last stable version (today: 4.12.3). Be careful: migrate also plugins to latest versions! Be also careful, because of the huge volume of data you have, the database migration may take long time…
Test and enjoy
Note that version 5 of Matomo may probably be released next year. It’s really time to migrate!