Panels and Transformations

Panel Types

Each panel type serves a specific visualization purpose. Choosing the right panel type makes data easier to understand. Match the panel to the data shape and the question you are answering.

Time Series Panel

The time series panel is the most common Grafana panel. It displays metrics as lines, bars, or points over time. It supports multiple queries, legends, and fill modes.

{
  "targets": [
    {
      "expr": "sum by(endpoint) (rate(http_requests_total[5m]))",
      "legendFormat": "{{ endpoint }}",
      "refId": "A"
    }
  ],
  "fieldConfig": {
    "defaults": {
      "custom": {
        "drawStyle": "line",
        "lineWidth": 2,
        "fillOpacity": 10
      }
    }
  }
}

Stat Panel

The stat panel displays a single value prominently. It can show color based on thresholds and is ideal for KPIs, current values, and status indicators. Use it for the top row of a dashboard.

# Current request rate
sum(rate(http_requests_total[5m]))

# Active instances
count(up == 1)

# Error percentage
sum(rate(http_requests_total{status=~"5.."}[5m]))
  / sum(rate(http_requests_total[5m])) * 100

Heatmap Panel

The heatmap panel visualizes histogram distributions over time. Each column represents a time bucket, and color intensity shows the count of observations in each value range. Heatmaps reveal distribution shifts that line charts hide.

Thresholds and Overrides

Thresholds add color coding based on value ranges. Overrides apply specific settings to individual fields or series. Together they make dashboards scannable at a glance.

{
  "fieldConfig": {
    "defaults": {
      "thresholds": {
        "mode": "absolute",
        "steps": [
          { "color": "green", "value": null },
          { "color": "yellow", "value": 50 },
          { "color": "red", "value": 80 }
        ]
      }
    }
  }
}

Transformations

Transformations modify query results before rendering. They can join series, filter rows, rename fields, calculate derived values, and restructure data. Transformations are powerful for creating complex visualizations from multiple queries.

{
  "transformations": [
    {
      "id": "reduce",
      "options": {
        "reducers": ["mean", "max"],
        "fields": "/.*/"
      }
    },
    {
      "id": "sortBy",
      "options": {
        "sort": [{ "field": "Mean", "desc": true }]
      }
    }
  ]
}