Can you describe what “crashes” means? Does Luup reload? Does the entire box reboot? Does it just become unresponsive to anything? Is it just unresponsive at the UI but automations keep running? These are all important distinctions.
user_data in its entirety may require the Vera to build a very large result, particularly in XML. The
user_data structure is very large, even on a small system. I have nearly 200 devices (ZWave and virtual/plugin) on my production Vera, and
user_data in XML form for me is about 2MB (2048K), and takes a little over three seconds to generate and transfer. JSON format is about the same size, but takes less than 1/2 second to generate and return. Typically, the UI, for example, will request
user_data once (in JSON), and then request deltas (changes) from that initial result, so its use is more efficient.
Frequent requests for all of
user_data could conceivably cause spikes in memory usage leading to a crash. But perhaps more to the point, you’re probing the system’s responsiveness by doing one of the most responsiveness-killing tasks you can do.
Since 7.30, I have observed that lighttpd sometimes hangs returning large responses. Mostly I have noticed this when requesting the LuaUPnP.log file contents; I have not seen it in other contexts, but it could be happening here. Normally, the service restarts itself within a minute or so when it happens, so it self-heals and thus may be less noticeable to most users. Since you didn’t describe what “crash” means, this may or may not intersect the behavior you are seeing.