Zwave performance drops after Routine executes with offline devices

[h0ckeysk8er (Bruce Pinsky)]

@glenmm

I’ve been doing a lot of construction lately, adding Zwave devices (mostly GE with @philh30 's Edge driver) and unplugging some devices (e.g. a dimmer using SmartThings-smartthings-Z-Wave_Dimmer_Switch_Generic). I created some routines with the button-press scene capability of the GEs and noticed some routines were just not running right, they were very delayed, and the switches themselves became non-responsive for a period. During that time Zigbee devices were just fine. My hub is running 0.47.11 firmware.

I traced the issue to the offline devices. Here’s what I found:

1. If there is a Zwave offline device in a Routine, the routine will lock up for 20-30 seconds before other online devices will receive commands in that routine.
2. Even so much as changing on/off state or dim state of an offline device will cause this issue (i.e., it’s not just when an offline device is in a Routine) - this is easy to reproduce, just find an offline device, try to turn it on, and watch all your Zwave devices go off the rails.
3. For a period of about 2 minutes from initiating a Routine that contains an offline device or trying to operate an offline device, all Zwave devices and Routines will experience a period of poor response time, no matter if they are Edge or Groovy, and no matter if it’s done from the app or a Routine from a button/scene.

I solved the issue by removing offline devices from active Routines.

Almost seems like the Zwave stack is single-threaded. At best it’s hanging on trying to talk to another device that won’t respond because it’s offline, and stopping up the works on the entire Zwave stack.

Anyone else experience this? I’m willing to bet a lot of people’s vexing performance issues can be traced to offline Zwave devices, probably being hit in Routines. I can’t say this is recent or not with the latest firmware, because I just started noticing this as I recently was adding and shifting a number of devices.

I’ll let @JDRoberts discuss all the in’s and out’s of Z-Wave repeaters and what happens when a device goes offline

One thing I have noticed during the move to Edge is that S2 security plays a bigger role in affecting Z-Wave individual device and network performance. If you have devices that previously weren’t S2 authenticated and then get moved to an Edge driver, there have been reports (and I experienced) of non-responsive devices and devices preventing proper communication with the hub. Another thing I noticed is that S2 security devices with a large number of settings can flood the Z-Wave queue and cause other devices Z-Wave commands to be delayed or dropped.

I would suggest checking each of your Z-Wave devices in the API Browser+ for its NW Security Level and if you have ZWAVE_S2_FAILED devices, you should re-pair them to get to ZWAVE_S2_AUTHENTICATED state. While I can’t say for sure that will fix all the issues being reported, it’s one less variable in the equation.