Math not possible with Host variable

[sonet]

I am attempting to add metrics together using a Math operation (I’m trying to return total bandwidth from multiple interfaces) and then graph it as a single metric. I do not want to stack these metrics because there are too many.

I am able to do this without issue if the Host is specified as a static host. As soon as the host is a variable (e.g. $hostname), it does not work - the graph simply says ‘no data’ immediately.

All of the other graphs I created for the same variable $hostname are working without issue, but if I try to add any Math operations of any sort to those working graphs they also change to ‘no data’ immediately.

The data source is Zabbix.

Anyone have any ideas of what could be causing this?

[alexandrearmand]

not sure about what happen here, if you can share your query
maybe you can check with your data inspector, to see what is data is pulled from zabbix.

something weird is you are saying you try to apply math operation with $hostname variable.
You can’t make operation with string (maybe a type issue)