grafana-pcp | Performance Co-Pilot Grafana Plugin | Analytics library

I have a number of servers where PCP Vector is running with standard settings and I want to have some metrics from these servers plotted on graphs in Grafana. I followed the quickstart guide and was able to query metrics properly from PCP Vector data source with a predefined target host. However I would prefer to have one data source and use a dashboard variable for the target hostname, so I can monitor any host I want from one dashboard using the same data source as it is described here. I followed the instructions for multiple vector hosts, but it did not work. I tried:

• server mode, browser mode;
• blank URL in the data source, then an override value in the graph settings with the $host variable or with the actual hostname typed it;
• URL set in the data source, tested positively, then overridden in the graph settings;
• URLs with and without the trailing slash.

In every case I was getting Network error and no data on the graph. I am not sure if the problem is with Grafana or the Vector plugin.

I am using:

• Grafana v7.0.0 (aee1438ff2)
• PCP Vector plugin v2.0.2
• PCP webapp on the target host installed from the package pcp-webapp-vector-4.1.0-5.el7_6.noarch

Please post comments if you need more debug information.