Sankey Diagram Widget

The Sankey widget can render results as a two-level Sankey diagram. It is good at displaying flows between entities, such as network flows from one IP to another.

The Sankey widget can also be triggered by calling the sankey() function.

See in Figure 171, “Sankey Widget” an example of how this widget may look like.

Sankey Widget

Figure 171. Sankey Widget


Input Format

The table below defines the required fields in incoming events for use with a Sankey widget.

Field Type Description
source string The ID of the source node (left side). This value will also be used as the label of the node.
target string The ID of the target node (right side). This value will also be used as the label of the node.
weight number The value that is used to determine the size of the edge between source and target, scaled automatically. This could be used to represent the traffic between two IP addresses.

The Sankey widget is most easily used with its companion query function sankey(), but can easily be used simply by ensuring the input fields are named as expected.

Sankey Example 1: Network Traffic

Here we are using the companion query function to visualize data flowing from src_ip to dst_ip. We use the sum() function to calculate the total number of bytes sent — where pkt_size is a field containing the packet size.

logscale
sankey(source=src_ip, target=dst_ip, weight=sum(pkt_size))
Sankey Example 2: Thread Usage

In some situations it might be easier to produce the input data manually instead of using the companion function.

logscale
rename(class, as=source)
| rename(thread, as=target)
| groupBy([source, target], function=count(as=weight))

In this case we want to visualize which classes use which threads in a service. We need to rename the class and thread fields to match the expected input; we do this using the groupBy() function, and to produce weight fields, we make sure that the function we use in the groupBy() names its result weight.

Widget Properties

Use the widget's Edit Style panel to configure the following properties.

  • Title

    The title of the widget as displayed in the dashboard.

  • Description

    The description of the time chart. This is free form text supporting markdown syntax.

    This same description appears in the dashboard as a tooltip by hovering over the question mark on top of the widget.

  • Axes

    • Show Y-axis

      Shows values in the vertical axis.

  • Stack Sorting

    Controls the order of the series in each stack.

    • Type arranges series by:

      • Label — sort by the series label name.

      • Size — sort by the series size.

    • Order

      Arranges series by ascending or descending order (alphabetical if sorted by label, numerical if sorted by size).

      Valid options are:

      • Ascending

      • Descending

  • Labels

    • Label position

      Choose where you want the labels to appear in the chart. Valid options are:

      • Inside — positions the labels within the chart area.

      • Outside — positions the labels external to the chart area.

    • Max Length

      Sets the length of the label — smaller values will show labels as truncated.

  • Series

    Allows to change the color and the displayed name of each series in the diagram.