Device with no output / Stack dump.

[MatthewHink]

Device.Output is a string.
When GetOutput() unable to map the string to an Output, MakeReading will fail with a stack dump.
When there are currently 882 devices on a VEM-150, the stack dump is insufficient to debug which device is causing trouble.

Possible solution:
a. Check at configuration time that each configured Device.Output maps to a valid Output.
b. Check at runtime during MakeReading for a nil output.
For each case: Log enough information to determine the device and shut down the plugin gracefully.

The repro is basically to create a device with something like Output: "output_does_not_exit"

[MatthewHink]

Would not be too surprised if there are similar issues around other string fields in struct Device (worth a look).

[edaniszewski]

I think this is being done at configuration time (or, when devices are loaded from configuration)

synse-sdk/sdk/device.go

Lines 237 to 245 in 64f5771

	if instance.Output != "" {
	if output.Get(instance.Output) == nil {
	log.WithFields(log.Fields{
	"prototype": proto,
	"instance": instance,
	}).Error("[device] unknown output specified")
	return nil, fmt.Errorf("new device: unknown output specified '%s'", instance.Output)
	}
	}

As for whether or not enough info is being logged -- probably not. It looks like it is logging the device instance and device prototype structs, but given that they are pointers, I'm not actually sure its logging anything useful there