I am trying to setup dashboard for http requests, but I am not able to get metrics on which time it got failed and the url to which it is being fired. The requirement is to run builtin metrics query and create a dashboard with below details
Application Name URL LastSuccess@ LastError
I think it is not possible to do exactly what you want, at least in a direct way.
I suppose you've checked all "synthetic.http." metrics available related to HTTP Monitors (i.e: Result Status Count [by request, location] splitting by HTTP Monitor Step).
Have you considered the option of getting that info from API v2 for HTTP Monitors?
Could you please describe how are you trying to push de variables to metrics?
I would use the Ingest Metrics API to push the variables to metrics in a HTTP monitor's post-processing step: