Line chart

A line chart plots data points connected by lines, making it ideal for visualizing trends and changes over time. You can compare multiple series on the same time axis and use a secondary Y-axis to correlate metrics with different scales.

Creating a line chart

The following examples build on each other, starting with a basic chart and adding complexity. They use the sample web log dataset. Before you begin, complete the prerequisites.

Basic line chart

Start with an aggregation query that counts events over time:

source = opensearch_dashboards_sample_data_logs | stats count() by SPAN(@timestamp, 1h)

After running this query, the visualization editor automatically selects a Line chart and maps the fields:

• The X-Axis displays the SPAN(@timestamp, 1h) field.
• The Y-Axis displays the count() field.

The result is a single line showing the event count per hour, as shown in the following image.

Multi-series line chart

Add a third dimension to your query to split the data into multiple series by category:

source = opensearch_dashboards_sample_data_logs | stats count() by SPAN(@timestamp, 1h), response

This query groups the count by both time and the response field (HTTP status codes). Select response as the Color field to render a separate line for each status code value (for example, 200, 404, 503).

The result is a multi-series line chart where each HTTP response code is displayed in a distinct color, as shown in the following image.

Multiple Y-Axis fields

When your query computes multiple metrics, you can plot them all on the same chart:

source = opensearch_dashboards_sample_data_logs | stats avg(bytes), max(bytes) by SPAN(@timestamp, 1h)

This query returns two numeric fields: avg(bytes) and max(bytes). Select avg(bytes) and max(bytes) in the Y-Axis field list to plot them as separate lines on the same scale.

The result shows both the average and maximum byte values over time, as shown in the following image.

Secondary Y-Axis (dual axis)

When two metrics have significantly different scales, plotting them on the same axis can make one appear flat. Use the Y-Axis (2nd) field to give the second metric its own scale on the right side of the chart.

Using the same query as the previous example:

source = opensearch_dashboards_sample_data_logs | stats avg(bytes), max(bytes) by SPAN(@timestamp, 1h)

This time, assign avg(bytes) to the Y-Axis and max(bytes) to the Y-Axis (2nd).

The result is a dual-axis chart. The left axis scales to avg(bytes) and the right axis scales to max(bytes), as shown in the following image.

Configuring a line chart

You can configure the following settings in the configuration panel.

Fields

In the Fields section, configure the fields displayed on each axis.

Split

In the Split by dropdown list, select a field to split the chart into separate elements by value. For more information, see Split.

Line

The following table describes the line style settings.

Thresholds

For information about configuring thresholds, see Thresholds.

Axes

The X-axis and Y-axis share the same configuration options. For more information, see Axes.

Tooltip

Toggle the Show tooltip selector to enable or disable tooltips.