I know there is a config java additional arg for project scan frequency, and it used to be in the upgrade guide but I can’t find it anymore.
Does someone here know what it is or where in the documentation it is?
The documentation used to say something about it changing to 10 minutes in Ignition 8.0 from 7.9
There’s no concept of ‘scan frequency’ in 7.9, because the only ‘source of truth’ for project resources is the gateway’s internal DB.
In 8.0, when resources moved to the filesystem, we put a system in place to watch the filesystem for changes to resources; if an external change is made, it’ll be detected and override the configuration the gateway has in memory. However, the scan frequency was fairly aggressive and could, on systems with many projects, consume a significant chunk of CPU.
As a result, in 8.1, we lowered the time to scan from a hardcoded default 10 seconds to a configurable 5 minute default rate. The ignition.conf parameter to change is -Dignition.projects.scanFrequency=10: 8.0 to 8.1 Upgrade Guide - Ignition User Manual 8.1 - Ignition Documentation
Ahh it was in the 8.1 doc! I was thinking it came in 8.0 so I was looking in the wrong place.
May be good to add it to this page in the documentation as well:
https://docs.inductiveautomation.com/display/DOC81/Gateway+Configuration+File+Reference
Nit-pick: it was never hardcoded, that system property has always existed.
TIL. Guess that makes sense, I just assumed for some reason it came in with 8.1.
Out of curiousity, does that technically mean this config option would exist in 8.0 as well?
Yes, it just has a much faster default value in 8.0.
For prosperity, I noticed it was added!
https://docs.inductiveautomation.com/display/DOC81/Gateway+Configuration+File+Reference#ProjectDirectoryScanRate