Single Value Widget

The Single Value widget can either display a single number — errors per day or active connections to a system, for example — or string values, like for instance words e.g., "Success" or even symbols.

This widget can display any data with a single row and a single field, containing a number or a string.

See in Figure 144, “Single Value Widget” an example of how this widget may look like.

Single Value Widget

Figure 144. Single Value Widget


Because this widget can display any "single" value (regardless of whether it's a number or not), a row with multiple fields in it would not make sense as you would have multiple potential values to pick from; therefore, if there are multiple rows, or there are multiple fields in a row, the widget will present an error.

An exception to the above behaviour is possible by using the timeChart() function, in which case there can be multiple rows or data, used to calculate a trend — see Example: Displaying a Trend with a Timechart for more details.

Input Format

The Single Value widget is often used in conjunction with functions such as sum(), count(), or avg() which produce a single row with a single field, like _sum.

The widget can also be used on data where you have produced a single row with only one field. The select() and selectLast() functions are very useful for this.

Example: Displaying Number of Errors

To show the number of errors in a system, you could count them using:

logscale
loglevel = /error/i
| count()

This produces a single result with a field _count. The Single Value widget will automatically select the first numeric field it sees and use it as the value to display.

Example: Displaying Statistics from a Build

If you use LogScale to monitor how your software is building, your build pipeline might already output the numbers you want, like the number of failed tests. Instead of calculating this number based on the failed tests that have been logged, you can display the number the system has given you:

logscale
commit = 67686a1
| /Tests failed: (?<tests_failed>\d+)/
| select(tests_failed)

Assuming there is only one build per commit, this search extracts the number of tests that failed in the build, and uses the select() function to remove extraneous fields from the row. Without calling select(), the row might contain multiple numeric fields, and the Single Value widget would not know what to display.

Example: Displaying a Non-Numeric Value

The examples above described use cases with number values; instead, the following example shows how the Single Value widget can also display a non-numeric value; for example, you may set an emoji symbol to depict the state of a particular outcome from your events:

logscale
tail(1)
| case {
    fieldA = "true"
| emoji := "😀"
    *
| emoji := "😔"
}
| select(emoji)

This query produces a single result with a field called emoji and specifies that the emoji will be set to "😀" if a given fieldA is true, else it will be set to "😔":

Non-Numeric Single Value Widget

Figure 145. Non-Numeric Single Value Widget


Example: Displaying a Trend with a Timechart

The Single Value widget can be efficiently used in conjunction with the timeChart() function.

logscale
timeChart(span=1h)

This query produces a result containing the number of ingested events per hour. The result contains two fields: _bucket and _count. The _bucket field annotates each bucket with a timestamp, whereas the _count field is the value (number of events ingested).

Single Value Widget with timeChart()

Figure 146. Single Value Widget with timeChart()


When used with a timeChart() function in the search, specific styling options become available for the widget, allowing it to show the following:

  • A value — The main central number indicates the value, in this case _count, in the last bucket, depending on whether the Last Bucket property has been set to include it or not, see Widget Properties.

  • A trend — The difference in the value field, in this case _count, over the selected period. This is calculated by subtracting the value of the first bucket from the value of the last bucket.

  • A sparkline — Illustrates the value over time if the Sparkline property is toggled (see Widget Properties). Along with the trend, this is useful to give some context to the value that you're looking at. For example, it can indicate whether the value you're looking at is volatile, or if it's relatively stable.

Widget Properties

From the widget menu (see Figure 102, “Widget Menu”) click Widget to set the properties in the Styling panel. All the possible available properties are described in the list that follows.

There are some special properties that don't apply all the time, they are instead only available when the Single Value widget uses the timeChart() function in the search: in the list below, these special properties are highlighted with a note. Their use case is described at Example: Displaying a Trend with a Timechart.

  • Title

    The title of the widget as displayed in the dashboard.

  • Description

    The description of the 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.

  • Text

    • Label

      Provides a definition to be displayed along with the number or text. For example, Number of Errors.

  • Value

    • Format

      The available units that can be used to express values. Valid options are:

      • Raw shows the actual numbers (e.g., 4987).

      • Metric formats the value as a number with appropriate rounding (e.g., 4987 will be shown as 5k).

      • Time converts the value to a time span (years, months, days, hours, minutes, seconds...), depending on the input type selected.

    • Input type

      Enabled when the Time format is selected, gives the input units available to express values.

      Valid options are:

      • Milliseconds

      • Seconds

    • Decimal places

      Enabled when the Raw or Metric formats are selected, indicates the number of digits past the decimal point. It is possible to do number rounding by providing negative decimal places e.g., a decimal place of -2 would format the number 123 to 100.

    • Suffix

      Allows to provide any symbol or definition useful to describe the resulting value. For example, $ or ms.

  • Buckets

    Note

    This property is available only when the timeChart() function is used.

    Controls whether the first and last buckets that are currently receiving live data must be shown in the embedded timechart or not. Valid options are:

    • First Bucket

      The first bucket might be incomplete. If it's included, the trend and the sparkline will be affected. Options are:

      • Exclude

      • Include

    • Last Bucket

      The last bucket might be incomplete. If it's included, the trend, sparkline and actual value will be affected. Options are:

      • Exclude

      • Include

  • Trend

    Note

    This property is available only when the timeChart() function is used.

    When toggled, shows in the timechart the delta between the value of the first bucket and the value of the last bucket.

    • Show as

      Allows to choose the format of the trend value between two options:

      • Absolute value

      • Percentage

  • Sparkline

    Note

    This property is available only when the timeChart() function is used.

    When toggled, draws the timechart line or curve that estimates the relationship between the main single value and the trend.

    • Style

      Controls the appearance of the sparkline in the timechart. Options are:

      • Gradient applies gradient colors to the sparkline area fill.

      • Line draws just the sparkline without any fill.

    • Show line for zero checkbox

  • Colors

    Controls the colors of the widget for the different available methods.

    • Method

      Dropdown menu options are:

      • Static — controls the color of the number or string in the widget using the Text field; modifies the background color using the Background field.

      • By threshold allows to set thresholds for specific ranges in numeric value results, thus displaying the result in different colors.

      • By trend allows to customize the color profile of the displayed single value by trend (see this option explained at Example: Displaying a Trend with a Timechart).

      When the By threshold method is selected, the following properties allow to change the color of the resulting value.

      • Critical High — the result is displayed in red if it exceeds the value set in this box.

      • High — the result is displayed in yellow if it exceeds the value set in this box.

      • Low — the result is displayed in yellow if it is below the value set in this box.

      • Critical Low — the result is displayed in red if it is below the value set in this box.

      For example, a result of 600 turns red if you've set 500 as Critical High.

      The result is colored green by default when no thresholds are set, or in case it's in between the values set in Low and High boxes.

    When the By trend method is selected, the following properties allow to customize the colors of the different outputs in the widget, which can be:

    • Neutral — the default color is grey.

    • Positive — the default color is green.

    • Negative — the default color is red.

    For any of the above outputs, colors can be set for both Text and Background.

    In dark mode, the default text colors are a tad darker and the background is black.