Persistent file not upated

[masterd89]

Hello,

i want to implement an object server, which should keep the state of some Group Addresses during power outages ( which could cause the bus to be reset ). I set up some DEVICE nodes with the Read flag set, and i selected "Read the last value saved to file" as option. That is to keep the values in case the server on which nodered runs goes down too.

From what i understood, the persist file is saved about every time a telegram i received: in my experimentation however, i see the file being written only when i restart nodered entirely.
In my specific scenario, the container is stopped every night for backup purposes, and so it "samples" the state of the DPT at that time. As an example of the inconvenience, if nodered reboots for whatever reason during the day, "Night mode" would then end up enabled because the node reads a stale persist file.

Is there a way to force the file to be updated more often?

Grazie,
Davide

[Supergiovane]

Ciao Davide
the persist file is saved upon KNX connection lost or reboot. That choice was made at the beginning of developing the node, not to wear the SD cards in the RaspberryPI (writing to SD cards shorts the lifespan).
Now many users runs node-red in docker or VM, instead of RaspberryPI.
Sure i can change that behaviour, by setting up a timer that saves the persist file every xx seconds.
Please take a look at the AutoResponder node as well, maybe it can be useful https://github.com/Supergiovane/node-red-contrib-knx-ultimate/wiki/KNXAutoResponder.
Ti faccio sapere appena è online la versione aggiornata.

[Supergiovane]

node-red-contrib-knx-ultimate@3.3.40 is out.
Ciao!!

[masterd89]

Hello Massimo,
Thanks for the immediate reply!

I understand, i guessed that was a matter of reducing SD writes. As a matter of facts i am using nodered on a RPI, so the issue could potentially affect my setup as well.
However, nowadays one could get an oversized SD card for very cheap, with that much extra space and hopefully some wear leveling mechanism the issue should be mitigated.
Your solution should solve the issue for my scenario, thanks!

I missed the Autoresponder node, actually i can use that as well! Using DEVICE nodes seems easier to setup, but i'll give that a try!

Grazie mille!
Ciao,
Davide

[Supergiovane]

Ciao Davide
grazie della donazione!!!
Puoi ovviare anche usando una SD di tipo "industrial". Si trovano anche su amazon.