smdn / pseudomuninnode Goto Github PK

I would like to return "U" as a (plugin).value when the plugin failed, but there is no way to return "U".
http://guide.munin-monitoring.org/en/latest/reference/plugin.html

Attribute: {fieldname}.value
Value: integer, decimal numbers, or “U” (may be signed). For DERIVE and COUNTER values this must be an integer. See rrdcreate for restrictions.

Is there any good way to do that? My idea is like this.

change this line
https://github.com/smdn/PseudoMuninNode/blob/master/src/PseudoMuninNode.cpp#L180
writeResponse(field->name + ".value " + isnan(field->value) ? "U" : field->value, client);
and plugin returns std::numeric_limits<double>::quiet_NaN() when it failed.

Any better ideas are welcome.