This is something I wrote up after playing with the context options. I've filed a PR with some of this added to the Node-RED documentation but thought I'd release it here also. I hope people find it useful. Paul A guide to understanding 'Persistent Context' Prior to Node-RED v0.19.0, data could …

Hi, just a quick confirmation if I have correctly understood: the "persistent contexts" are written within the files with a specified timing that can be settled with the "flushInterval" option when "cache" is enabled This is used just as a backup to maintain the value at node-red restart. This mea…

[image] Lupin_III: Is that correct? With the default configuration of the file context store, that is correct - it uses an in-memory cache. But you can configure the store to not use a cache and any get/set operation is done on the file directly.

Ok. So, to configure the store to not use a cache and have any get/set operation done on the file directly, the "cache" option has to be set to false. Right? [image]

If you change 'cache' to false, Eash time you store a value, the context will be written to storage. As it says in the documentation: The flushInterval is provided to minimise wear on the underlying storage, such as on a Raspberry Pi’s SD card. Note that if Node-RED is unexpectedly killed, any da…

Hi [at]all, so far I what have read about persistent context, I tried to solve this myself with doing the following: though for me its not a decisive target to have my global context stored practically "realtime". and probably for many others it isnt AW. since function nodes provide the possibili…

to store it, it needs to be serialisable... this is generally not possible for actual functions and a few other types of objects (eg maps I think). Basic object type are fine.

Reading through this topic I assume that deletion of stored data is still not included as default option? Some people mention the change node. How to use this node to delete data?

I would set a variable to the value null personally. Not sure if that deletes it though, can't remember I'm afraid.

I'm not sure what you mean by: [image] Hunter: deletion of stored data is still not included as default option You can use a change node with the `delete option[Screen Shot 2021-04-13 at 4.23.37 PM]

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A guide to understanding 'Persistent Context'

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Topic		Replies	Views
Problems understanding and implementing Persistent Storage General	42	1331	31 August 2023
🎉 Node-RED 0.19 released News	57	4463	10 January 2019
:question: DISCUSSION: Should nodes save/restore their own context? General	95	4826	19 August 2020
Questions about context saving and something more General	13	358	7 January 2024
Node-red won't start General	63	3745	23 November 2020

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A guide to understanding 'Persistent Context'

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