Grafana Oss

Grafana Panels and Visualizations - Detailed Reference

What is a Panel?

A panel is the basic building block of a Grafana dashboard. Each panel combines:

• A query (or multiple queries) to a data source

• A visualization type to display the data

• Field configuration (units, thresholds, color mappings)

• Optional transformations to reshape the data before display

Panel Editor

Open the panel editor by clicking a panel's title > Edit, or clicking Add visualization for a new panel.

Panel Editor Layout

Top bar: Back to dashboard, Discard changes, Save dashboard

Center: Visualization preview (live update as you configure)

Toggle: "Table view" - shows raw query results as a table for debugging

Right sidebar tabs:

1. Query - configure data sources and write queries

2. Transform - apply data transformations

3. Alert - create alert rules from this panel

4. Below tabs: visualization-specific options and field config

Query Tab

• Data source selector: Choose which data source to query

• Query editor: Data-source-specific interface (PromQL for Prometheus, LogQL for Loki, SQL for databases)

• Query options:

  • Max data points: Limit data points fetched

  • Min interval: Minimum auto-calculated interval

  • Interval: Override the auto-calculated interval

  • Relative time: Override dashboard time range for this panel only

  • Time shift: Shift the time range (e.g., to compare to last week)

• + Query: Add multiple queries (labeled A, B, C...)

• Expression: Add server-side math expressions combining query results

Visualization Types

Time Series (default)

Best for: Metrics over time, continuous data

• Renders as lines, points, or bars

• Supports multiple series

• Configurable line width, fill, point size

• Supports thresholds as colored background regions

• Supports annotations overlay

• Graph styles: Lines, Bars, Points; can mix per series

• Stacking: None, Normal, 100%

• Axis: Left Y, Right Y, hidden

• Default visualization - supports alerting

Stat

Best for: Single important metric (KPI display)

• Shows one or more values as large text

• Supports sparkline background

• Color modes: value, background, none

• Can show last value, mean, sum, etc.

• Great for dashboards that need quick status overviews

Bar Chart

Best for: Comparing categorical data

• Horizontal or vertical orientation

• Grouped or stacked

• Supports labels on bars

Gauge

Best for: Showing a value relative to min/max range

• Circular gauge with arc

• Configurable thresholds set colors

• Shows current value prominently

Bar Gauge

Best for: Multiple metrics as horizontal/vertical bars

• Useful for comparing many items

• Supports thresholds for color coding

• Modes: gradient, retro LCD, basic

Table

Best for: Tabular data, multi-column metrics

• Supports sorting by column

• Column width customization

• Cell display modes: color text, color background, gradient gauge

• Pagination for large datasets

• Can embed sparklines in cells

Heatmap

Best for: Distribution over time, histogram-over-time

• X axis: time; Y axis: buckets; Color: density/value

• Supports pre-bucketed data (Prometheus histogram) and raw values

• Tooltip shows exact bucket counts

Histogram

Best for: Value distribution analysis

• Groups values into buckets

• Can combine multiple series

• Configurable bucket size

Pie Chart

Best for: Proportional data, parts-of-whole

• Pie or donut style

• Labels: name, value, percentage

Logs

Best for: Log data from Loki, Elasticsearch, etc.

• Displays raw log lines with timestamp

• Log level coloring (info/warn/error)

• Search/filter within results

• Deduplication and time wrapping

• Prettify JSON option

Traces

Best for: Distributed tracing visualization (Tempo)

• Renders trace spans as a waterfall/Gantt chart

• Shows service name, operation, duration

• Click to drill into trace details

Flame Graph

Best for: CPU profiling data (Pyroscope)

• Visualizes call stacks by CPU time

• Click to zoom into subtrees

Node Graph

Best for: Service dependency maps, network topology

• Renders nodes and edges

• Node color/size configurable by metric

Geomap

Best for: Geographic data visualization

• Layers: markers, heatmap, route

• Multiple base map options (OpenStreetMap, CARTO, etc.)

• Supports GeoJSON data

Canvas

Best for: Custom layouts, process diagrams, status boards

• Drag-and-drop element placement

• Elements: text, metric value, rectangle, ellipse, icon, image, connections

• Dynamic data binding per element

State Timeline

Best for: State changes over time (on/off, OK/warn/crit)

• Horizontal bands showing state duration

• Each series = one row

• Color per state value

Status History

Best for: Periodic state checks over time

• Grid: Y=services, X=time buckets

• Color per state

XY Chart

Best for: Correlation between two metrics

• Scatter plot

• X and Y axis from different fields

• Bubble size from a third field

Candlestick

Best for: Financial OHLC data

• Open/High/Low/Close representation

• Volume bars

Text

Best for: Documentation panels, headers

• Renders Markdown or HTML

Alert List

Best for: Dashboard overview of current alert states

Dashboard List

Best for: Navigation panels linking to other dashboards

Field Configuration (Standard Options)

Available for most visualizations under the visualization options panel.

Thresholds

Define color-coded boundaries:

• Absolute: Fixed numeric values (e.g., >90 = red, >70 = yellow, else green)

• Percentage: Relative to min/max

Example threshold config:

Base (default): Green
70: Yellow (warn)
90: Red (crit)

Value Mappings

Transform raw values into human-readable labels or colors:

• Value to text: e.g., 1 -> "OK", 0 -> "Down"

• Range to text: e.g., 0-50 -> "Low"

• Regex to text: Match patterns

Data Links

Create clickable links from panel values:

• Link to other dashboards with variable values interpolated

• Link to external systems (e.g., Kibana, PagerDuty)

• Use ${__value.raw} and ${__field.name} in URLs

Field Overrides

Apply specific field options to individual series/columns rather than all data:

1. Click + Add field override in the Overrides section

2. Choose override target:

   • Fields with name (exact match)

   • Fields with name matching regex

   • Fields with type (number, string, time)

   • Fields returned by query (A, B, C...)

3. Add properties to override (unit, color, alias, thresholds, etc.)

Example: In a table with columns cpu_idle and cpu_used, set cpu_used to show as percentage and color by threshold while leaving cpu_idle with default styling.

Transformations

Transformations reshape query data before rendering. Apply multiple in sequence.

Access: Panel editor > Transform tab > Add transformation

Most-Used Transformations

Enable "Debug" toggle on any transformation to see input/output for troubleshooting.

Query Options

Multiple queries

Add multiple queries (A, B, C...) to one panel. They are overlaid in the visualization. Use this to compare metrics or show multiple services on one graph.

Expressions (server-side)

Server-side expressions allow math across query results:

• Math: $A + $B, $A / $B * 100

• Reduce: Collapse a series to scalar

• Resample: Change time resolution of a series

• Classic conditions: Threshold logic (used in alerting)

Example - calculate error rate as percentage:

Query A: total_requests{job="api"}
Query B: error_requests{job="api"}
Expression C (Math): $B / $A * 100
Display C as percentage

Important query variables

These variables are available in queries:

Example PromQL using interval variable:

rate(http_requests_total[${__rate_interval}])

Panel Inspect

Click panel menu (3-dot) > Inspect to access:

• Data: Raw table view of the data powering the panel

• Stats: Query performance (time, row count)

• JSON: Panel JSON model

• Query: Equivalent of query inspector showing raw query and response

Performance Tips

1. Limit max data points to avoid over-fetching

2. Use recording rules in Prometheus for expensive queries

3. Set longer min intervals for historical dashboards

4. Use $__interval variable in queries to align with time resolution

5. Use $__rate_interval instead of hardcoded intervals for rate() queries

6. Avoid too many panels on one dashboard (aim for <20)