Bar chart with color by threshold

Grafana Dashboards
1

  • What Grafana version and what operating system are you using?
    10.2.0

  • What are you trying to achieve?
    I want a bar chart with a different color for any bar which exceeds a threshold.

  • How are you trying to achieve it?
    I made a bar chart with color scheme “from thresholds (by value)”.
    I set decimals to 1.
    I set the base color to blue and a threshold to red.
    I set the soft min/max to 115 and 125 to make it easier to see.

With the threshold set at 123 all bars are red:

image
image1786×620 29.3 KB

With the threshold set at 124 all bars are blue:

image
image1782×624 29.1 KB

The data comes from Prometheus query: voltageLC1{site="$site", room="$room", job="PDU 1"} / 100. The raw numbers look like 12171 so I divide by 100 to get the voltage.

  • Can you copy/paste the configuration(s) that you are having problems with?
{
  "datasource": {
    "uid": "fcdbb9cf-3c1a-4fe7-ae16-f58d776c91ff",
    "type": "prometheus"
  },
  "fieldConfig": {
    "defaults": {
      "custom": {
        "lineWidth": 1,
        "fillOpacity": 80,
        "gradientMode": "none",
        "axisPlacement": "auto",
        "axisLabel": "",
        "axisColorMode": "text",
        "axisBorderShow": false,
        "scaleDistribution": {
          "type": "linear"
        },
        "axisCenteredZero": false,
        "hideFrom": {
          "tooltip": false,
          "viz": false,
          "legend": false
        },
        "thresholdsStyle": {
          "mode": "line"
        },
        "axisSoftMax": 125,
        "axisSoftMin": 115
      },
      "color": {
        "mode": "thresholds"
      },
      "mappings": [],
      "thresholds": {
        "mode": "absolute",
        "steps": [
          {
            "color": "blue",
            "value": null
          },
          {
            "color": "red",
            "value": 124
          }
        ]
      },
      "unit": "volt",
      "decimals": 1
    },
    "overrides": []
  },
  "gridPos": {
    "h": 6,
    "w": 12,
    "x": 12,
    "y": 16
  },
  "id": 10,
  "interval": "1m",
  "options": {
    "orientation": "auto",
    "xTickLabelRotation": 0,
    "xTickLabelSpacing": 100,
    "showValue": "auto",
    "stacking": "none",
    "groupWidth": 0.7,
    "barWidth": 0.97,
    "barRadius": 0,
    "fullHighlight": false,
    "tooltip": {
      "mode": "single",
      "sort": "none"
    },
    "legend": {
      "showLegend": true,
      "displayMode": "list",
      "placement": "bottom",
      "calcs": [
        "min",
        "max"
      ]
    }
  },
  "targets": [
    {
      "datasource": {
        "type": "prometheus",
        "uid": "fcdbb9cf-3c1a-4fe7-ae16-f58d776c91ff"
      },
      "disableTextWrap": false,
      "editorMode": "code",
      "expr": "voltageLC1{site=\"$site\", room=\"$room\", job=\"PDU 1\"} / 100",
      "fullMetaSearch": false,
      "includeNullMetadata": true,
      "instant": false,
      "legendFormat": "{{job}}",
      "range": true,
      "refId": "A",
      "useBackend": false
    }
  ],
  "title": "PDU Voltage",
  "type": "barchart",
  "description": ""
}
2

Ah I figured it out! I just had to change the gradient mode to “scheme”

image
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3

In case anyone is struggling like me to get this to work, make sure your visualisation type is “Bar chart” and not “Time series”.

For time series I was getting parts of the bar in different colours, not the whole bar. When I switched to bar chart it worked exactly as above.