Dear all, I run the embedded MQTT broker of openhab 2.4 (openhabian / Release = Raspbian GNU/Linux 10 (buster) / Platform = Raspberry Pi 3 Model B Rev 1.2). Although I use mapDB for persistence (and RRD4J for charting) - the status of switches wasn’t restored at startup. [image] How can one s…

[image] kriznik: MQTT and persistence is not working as others, so you have to use retained messages instead, which works as it’s needed. I disagree. Retained messages can lead to all sort of unwanted behaviours. I use a workaround. Although not perfect, I restored all the MQTT items. They a…

as it was answered in here [image] Influx, persistence and restoreonstartup? Items & Sitemaps sure btw all this mqtt is not really using restoreonstartup persistence explain why I’ve seen always errors within rules in logs, as those which are calculating stuff…

Thanks for sharing - it looks promising. I’m just wondering if there is a need to alter “mapdb” for my configuration? (I’m not familiar with previousState syntax …) [image] vzorglub: ii.postUpdate(ii.previousState(false,“mapdb”).state.toString)

It depends, my default persistence is influxDB so I need to specify mabdb in the method call to use mapdb otherwise it would use influxdb, which is slower at these kind of things. For the syntax: [image] Persistence a vendor and technology agnostic open source automation software for y…

[image] vzorglub: I disagree. Retained messages can lead to all sort of unwanted behaviours. well, various standards (homie for example) are using retain as default, there is nothing wrong with it, if you implementation is correct.

It’s not just about if you have selected retained messages (or Homie has done it for you). The MQTT binding currently acts unusually for bindings, and updates/the channel/Item at startup. You might get a retained value, you might get UNDEF if its not retained or the broker is sick or ill-informed. …

[image] rossko57: it tramples over any restore-on-startup you may have configured, no choices. I hope this will be addressed as soon as possible and that binding will act as others. @vzorglub workaround looks ok, but it’s quite tidious to put all mqtt items to separate group just because of …

[image] kriznik: I hope this will be addressed as soon as possible That turns out to be a whole philosophical question. If the broker is set to retain (and that broker mechanism is configured and working properly), all is well. If the target device chooses not to retain, the binding views t…

I think, if i remember correctly my logs during startup, mqtt items gets restored after restart from persistence, but then after binding gets online it’s switched to UNDEF (if there is no retained msg). I don’t see much room for philosophical discussion as it seems to be just bug … "i have data, he…

I agree with you, but let me present the opposing view: Consider some other binding, that polls a device. It’s broken, the binding knows its broken, there is no sensible data, it should update channel/Item to UNDEF. This is a Good Thing. The parallel for MQTT - at startup, we interrogate / refre…

[SOLVED] MQTT and restoreOnStartup

Setup, Configuration and Use Beginners

kriznik (kriznik) September 24, 2019, 8:53am 2

as it was answered in here

MQTT and persistence is not working as others, so you have to use retained messages instead, which works as it’s needed.