Charts

Charts are the visual forms used by dashboard and overview widgets. Most users choose a widget type rather than a chart directly; this page helps template authors understand what each chart is good for.

Time Chart

Used by line dashboard widgets.

Best for metrics that change over time: throughput, latency, error rate, queue depth, JVM memory, CPU, and similar series.

Behavior:

  • Supports one or more lines.
  • Shows a legend when there is more than one series.
  • Supports a second y-axis for mixed units, such as throughput and latency.
  • Shares hover position with other time charts on the same page, so operators can compare the same moment across panels.

Use card instead when the MQE expression returns a single scalar.

Top List

Used by top dashboard widgets.

Best for ranked lists: slow endpoints, high-traffic services, worst error rates, busiest instances.

Behavior:

  • Shows rank, name, value, and a proportional background bar.
  • Supports tabs when the widget has multiple ranking expressions.
  • Rows can navigate to an entity page when the result carries an entity reference.

Use line instead when the expression returns a time series.

Alarms Timeline

Used on the Alarms page.

Best for triage during an incident. It buckets firing and recovered alarms over time and lets the operator select a time range for the alarm table below.

Behavior:

  • Shows firing and recovered alarms as stacked bars.
  • Clicking a busy minute narrows the alarm list to that minute.
  • Dragging a range narrows the alarm list to the selected window.

Sparkline

Used in compact places such as tiles, sidebars, and picker rows.

Best for small trend hints where a full chart would be too heavy.

Behavior:

  • Renders a tiny trend line.
  • Shows a single dot when there is only one usable sample.
  • Shares hover position with related sparklines when the page supports it.

Colors

Charts follow the active Horizon theme. Use the layer accent or the theme accent for normal metrics, and reserve explicit colors for semantic states such as severity or error.