Grafana: Dashboards & Panels

Grafana is the leading open-source observability platform for visualizing metrics, logs, and traces. It connects to dozens of data sources and organizes data into dashboards made of panels.

Core Concepts

• Dashboard: collection of panels arranged in a grid — each saved as JSON, can be version-controlled

• Panel: a single visualization unit — time series, stat, table, heatmap, bar chart, etc.

• Data source: connection to a backend (Prometheus, Loki, InfluxDB, PostgreSQL, CloudWatch, etc.)

• Variable: template variable that makes dashboards dynamic — dropdown to filter by host, service, namespace

• Annotation: mark a point in time on panels — e.g., "deployment happened here"

• Time range: global dashboard time picker — "Last 1h", "Last 24h", or custom

Panel Types

• Time series: line/bar chart over time — default for metrics (CPU, memory, request rate)

• Stat: single large number with sparkline — current value with optional threshold coloring

• Gauge: circular progress indicator — fill % relative to min/max

• Bar chart: compare values across categories at a point in time

• Table: raw data in tabular format — supports pagination, sorting, column mapping

• Heatmap: visualize distributions over time (e.g., request latency percentiles)

• Logs: log lines from Loki — supports regex filtering, log context

• Node Graph: visualize service dependency graphs (traces/APM)

• Geomap: world map with data points — for geographic metrics

Dashboard Variables

Variables make dashboards reusable across environments/services.

Types:
  Query     — values come from a data source query (e.g., all hostnames from Prometheus label)
  Custom    — comma-separated static values
  Interval  — time interval ($__interval resolves to auto step)
  Text box  — free text input
  Constant  — hidden value (e.g., data source name)
  Data source — select a data source dynamically

Example — Query variable for host selection:
  Name: host
  Query type: Label values
  Label: instance
  Data source: Prometheus
  → Creates a dropdown: $host = "web-01" | "web-02" | "db-01"

Using in panels: rate(http_requests_total{instance="${host}"}[5m])

Dashboard JSON & Import/Export

# Export dashboard JSON
# Dashboard → Share → Export → Save to file (dashboard.json)

# Import from JSON
# + → Import → Upload JSON file or paste JSON or use Grafana.com ID

# Grafana.com dashboard library (thousands of community dashboards)
# Popular IDs:
#   1860  — Node Exporter Full (Linux system metrics)
#   3662  — Prometheus 2.0 Overview
#  13659  — Loki & Promtail logs
#  15489  — PostgreSQL overview
#   6417  — Kubernetes cluster monitoring