G'day all. I have a complex smart home setup with around 100 Zigbee devices and around 50 virtual devices, 16 dashboards with custom CSS, and about 50 complex rules in Rule Machine.
My Hubitat C-7 has been telling me that memory is low and although everything works pretty well most of the time, sometimes there can be a bit of a delay, sometiems a Zigbee device will drop off the network for a while and sometimes a contect sensor will report open when a door is open, but when the door is closed again the sensor will remain in the open state which requires the door to be opened and closed again, though this rarely happens.
I could potentially reduce the number of dashboards but there would still be at least 10 since every room has its own dashboard as well as theres a home dashboard which has a floor plan of the entire house on it with most devices displayed there.
I need some advice. Firstly is it likely that theres too much going on for my Hubitat C-7 to handle on its own and should I add a C-8 to the setup to handle the device connections while the C-7 handles the rules and dashboards? Is that a reasonable thing to do?
And if so, then how should I go about moving device connections to the C-8 while keeping everything working?
I'm hoping to find a solution since this setup is in a home for someone with a disability and it is also a workplace for her support workers, so keeping downtime to a minimum is important.
Something to note is that this setup is running completely locally with no internet access, however I do periodically connect it to the internet for firmware updates. Another thing to note is that in this setup there is also a Philips Hue Bridge connected which handles 31 Hue downlights, however the rules for those downlights are handled by the Hubitat C-7.
Any advice would be greatly appreciated. If there is a better solution that I'm not thinking of I'd like to hear that too.
I got similar advice about low memory issues. I'm going to migrate to C8 and then move some apps back to the original C7 after wiping it. See: Hub Low on Memory Alert, Have Questions - #81 by mavrrick58
Splitting up load between multiple hubs is certainly a way to help reduce load if that is truly were the problem is. Generally from what I have seen it looks like Zigbee and Zwave devices tend to be fairly lean if they are using built it drivers though.
I think i would start with loading the Hub Info driver by thebearmay
Then have that data captured and either graphed by Webcore with Hubigraphs, or InfluxDB Logger to a local/cloud Influxdb with grafana providing the visualization. To show something like this.
That will atleast let you know for sure if there is any CPU issue as well or just memory. and how well overall the device is running.
When you setup the HubInfo driver make sure you only enable the collections you need on reasonable intervals for what you need. It isn't to heavy but isn't without cost by itself.
If you really only have Zigbee and virtual devices then I would be surprised if memory consumption is related to the devices themselves. I would start to look at your rules in RM or other Apps. I would start to look at the rules and see if there are any that can be optimized.
Regardless of that, splitting the load between hubs may not be a bad idea to help split the work. Hub Mesh works great,
One thing to consider when migrating or moving to a C8 is that there are some Zigbee devices that are problematic with the Zigbee 3.0 radio in it. You may want to do a little bit of research to find out if you have any such devices.
A lot can depend on what brand of devices you have. For example, although some do report their Xiaomi Aqara and Mijia devices are relatively stable on C7, I gave up on joining Xiaomi and IKEA devices directly to HE long ago and instead use Home Assistant as a controller for them, together with Home Assistant Device Bridge to bring their state back into HE.
Like you, I have a Hue Bridge for all my smart bulbs, and for my dimmers I use a bridge software for my Insteon hub. I also have three HE hubs, but only two are in use. This is helpful for separating some old and very chatty Z-Wave energy monitors, and some community applications that I don't want on my main hub. However in regard to Rule Machine, all of my rules (well over 100) are on my main hub. Some are simple and some are complex. I don't experience slow performance or memory warning issues.
While I do encourage distributing the load, you may find it more helpful to look for a community app that may be the root cause of your particular issue. Try temporarily disabling suspects and see if you can find the root cause.