We have a relatively large Piwik installation (>30 Gbs of DB, last time I checked), so any major upgrade which involves modifications in the database takes a very long time (for example from 2.7 to 2.8)
Stopping access to the web interface is not a big deal, but 2 or 3 hours without statistics would be. Is there any procedure to perform updates without downtime? I thought about creating a pair of master-slave databases, but anyway we would need to ‘export’ the statistics taken during the upgrade to the newer version too, I don’t know if that would even be possible.
I guess this has been asked before, but I could not find any documentation about it
After Piwik was migrated to the latest version you can import from your server access logs, for the time window that Piwik was down. By replaying the server access logs with --replay-tracking you can recover the whole data. Learn more about: Log Analytics - Analytics Platform - Matomo (and see option --replay-tracking)
Would this solution work with multiple sites and domains in the same Piwik installation? I was afraid the import logs script would track all the visits as if they were to the same idSite.