Last week I was getting an error message when the client or designer tried to load the project stating “Error launching application: EOFException: null”. I was able to track the issue down to the cache becoming corrupted. This Edge device is operating off a Moxa Industrial PC using Ignition Mint whose main “Hard Drive” is a Compact Flash Card and is (and will always be) harshly shut down without powering down the system first.
To overcome this issue I’ve written a script to delete the ~/.ignition/cache each time the computer turns on prior to launching the vision client. However, I was wondering if there was a setting somewhere that would prevent the storing of the files in cache by default? It’s an edge device that will always be run locally off the PC so its not like I’m really gaining anything by storing things in a “local” cache.
You can’t not store Ignition’s packages in a local cache. They are jar files, for the most part, and are compressed. Much can be decompressed on demand into RAM, but the source (zip/jar) needs to be local for such on-demand decompression.
Consider adding an overlay filesystem that saves to RAM to “snapshot” your bare system. Or snapshot your system with the cache in place.
(This is basically the same as embedded Windows “Enhanced Write Filter”. Implementation will vary by distro–there’s a number of overlay technologies available in Linux, with various pros and cons.)
I’m having this issue as well with a Debian VM (and host) that often gets turned off by power loss. The overlay file system approach sounds above my (current) abilities, and I’m not sure a snapshot/restore on powerup makes sense with the current architecture (Gateway, Client, and database in a single VM).
Is there a drawback to just deleting the cache on boot and having it rebuilt? Does it just slow down the first load of an Ignition client?