[MQTT] To update several attributes with a single message

[panos]

@dcompent

However, the niche I am trying to address, is one addressed by the OP in the initial post in this thread–and several others dotted across the forums: DIYers, programmers, or project managers wanting to design a product around the default OpenRemote infrastructure. Where the goal is not to reinvent the wheel (i.e. donning a Java hat and writing a custom handler), but rather to leverage what is already present. And what is present is extremely data-inefficient for updating more than a single Attribute.

I understand where the need for this might emerge, especially for users that may not be that well-versed with software development. But, given that OpenRemote is an open-source project, you are more than welcome to create a new pull request!

@dcompent

Yes, you can cobble together OpenRemote JSON parsers and such in the UI–but it does not appear (as far as I yet know) that these are geared towards (or even usable) in auto-provisioning scenarios. (For one-off manually-setup and manually-configured implementations, though, they are a viable option.)

I was talking about using parsers within OpenRemote code, within the custom MQTT handler.

@dcompent

Links, please? The only example I was able to find anywhere online was the Teltonika MQTT handler –and it was an extremely valuable resource. Without real-world examples (to say nothing of documentation), those outside of the inner OpenRemote programming team stand very little chance of figuring out how to implement anything.

Yeah, I wrote that MQTT handler, it’s still a work in progress . It is a good place to start if I may say so myself, but also the MQTT Handler abstract class, that contains documentation for (I think) all of the methods you may want to implement. There’s also the forum thread about an MQTT sparkplug integration, where I go a bit more in-depth about how to create an MQTT handler.

I would also like to mention that I do not want to make a custom MQTT handler appear to be a one-stop-shop for all OpenRemote users with an MQTT device. I think that the pros for it outweigh its cons, if we remove the concept of required knowledge or time requirements. I just wanted to show this functionality as a very useful tool, which enables me to create integrations for devices at a level that has never been seen before.

@dcompent

keeping power requirements low is often extremely important for some systems. In addition to that, cellular systems are more often than not billed by the MB (if not the KB)–so every “little” savings becomes very substantial.
Especially if there are several hundred attributes to update. It’s even worse if each Attribute is 1-3 characters (think “Byte” status, 0-255): the overhead of the MQTT topic string alone at >80 bytes per Attribute simply cannot be ignored. (This isn’t even including all of the network stack overhead.)

Here you mention how power and bandwidth limitations are also quite significant for your use case. To me, this sounds like this could lead to real issues pertaining to cost. It also sounds like an implementation like this could be mission-critical for a project you may be taking on. This is one of those use-cases where I do believe that a custom MQTT handler would just make your life a lot easier. If people are thinking of network overhead for IoT devices creating unnessessary cost, then I do consider it to be an issue that deserves its own MQTT handler as a solution.

In total, I do understand that need of some users for writeattributevalues, but I also need to highlight the importance of custom MQTT handlers for use-cases like these. In any case, opening a pull request is free, and it would improve OpenRemote as a whole!