I have a json-http-request which gives me some kind of counter-value

I call http://xxx.mydomain.local/customers/served

which gives me

    {
        "data": {
            "customers_served": {
                "today": 34,
                "ever": 14800
            }
        }
    }

I am using the "HTTP XML/REST Value Sensor" and evaluate the node: /data/customers_served/ever I will get an ever increasing line as graphics because every day we get more customers served. This kind of graphics is good to display a temperature of a room.

But I am interested to look onto a graphic where I can see wether we are having a busy day or a day with low frequence of customers served. I am interested to see the *difference* to the last value in the graphics of PRTG. Is this possible to define somewhere?

Thanks, Richard

Article Comments

Hello richard-lippmann,
thank you for your KB-Post.

What you're looking for is a Delta(counter) sensor/channel. However, this is currently not possible with the HTTP XML Rest Value sensor. I would advise you to measure/poll the /data/customers_served/today instead, this may give you the graph that you're looking for.

Best Regards,
Luciano Lingnau [Paessler Support]


Aug, 2017 - Permalink

The nearly same situation, 2 years later.

How can I show difference values with in Grapics? I can only find the absolute value shown.

I have a json-http-request which gives me some kind of counter-value

I call http://xxx.mydomain.local/customers/served

which gives me

    {
                "nr_of_accesses_ever": 14800

    }

I tried:

  • REST Custom Beta, with channelDiscovery.

The sensor found the channel $['nr_of_accesses_ever']. The values are shown as absolute values, but not as difference value like "accesses/minute".

I haven't found a difference-computation in the settings of the channel.

Greetings, Richard


Nov, 2019 - Permalink

We have the same issue. Our bandwidth counter value is only accessible through a REST API. (rx_octets, tx_octets) How to build a bandwidth (bits/s) graph with a counter value from a JSON object. Is this still not possible?

Thanks, Benno


Dec, 2019 - Permalink

Hi,

Maybe you can use the Rest Custom Sensor to monitor the desired information. You can find more information about the Rest Custom Sensor here.

Kind regards


Dec, 2019 - Permalink