Explore charted data

This document describes how you can explore the data shown on a chart. For example, you can highlight specific time series and when you want more detail around a point of time, you can change the chart resolution. You can also view information about the chart—like legends and configuration data— which isn't shown by default.

Charts are used in many places in Cloud Monitoring. For example, dashboards contain charts, and individual charts appear in Metrics Explorer and in the interface for configuring alerting conditions. For information about creating charts, see the following documents:

About the chart toolbar

To display information about the chart, to download the chart to your local system, or to modify the chart, use an option in the chart toolbar. The specific options shown on the chart toolbar depend on the chart width and the chart type. Supported options that aren't shown on the chart toolbar are included in the Other options menu. You must use this menu when you want to do any of the following:

  • Download a PNG image or a CVS representation of the chart.
  • View associated logs in the Cloud Logging Viewer. For information about the Cloud Logging interface, see Viewing logs.
  • Edit the chart or change its mode. For example, you might change a chart from color mode to x-ray mode.
  • View the chart in Metrics Explorer.

When the dashboard toolbar contains the same option as a chart toolbar, the setting applied by using the chart toolbar overrides the dashboard toolbar setting.

Show the chart configuration

When you are viewing a chart on a dashboard, you might want to know exactly how the chart is configured. For example, you might want to know the details of the aggregation options or the exact Monitoring Query Language (MQL) query.

When you use Metrics Explorer, the chart configuration is always visible. However, when you view charts on dashboards, the configuration of those charts is hidden by default. To view the configuration of a chart on a dashboard, click Query stats when that button is shown in the chart toolbar. When that button isn't shown, place the dashboard in edit-mode and then select the widget.

The following example illustrates a tooltip shown by the Query stats button:

Example of a tooltip showing a chart configuration.

The previous example lists the metric type that is charted, the filters, the grouping options, and the alignment options.

For information about how to view the configuration controls for a chart, see Modify a widget's configuration.

Show the chart legend

To hide or show the legend, click Toggle Legend in the chart toolbar.

For more information, see Show and hide legends.

Show the chart fullscreen

To enlarge a single chart on a dashboard, click Fullscreen in the chart toolbar.

To exit full-screen mode, click Esc.

Show all charts at default resolution

To show all charts at the default resolution, click Reset zoom in the chart toolbar.

Show exemplars on a heatmap chart

To hide or show Cloud Trace exemplars on a heatmap chart, click Trace exemplars in the chart toolbar. Exemplars aren't always available. For information, see How to create Cloud Trace exemplars and Exemplar in the Cloud Monitoring API pages.

The following screenshot illustrates a heat map with Cloud Trace exemplars displayed. The light-blue circles on the chart show the exemplars. The data came from an OpenCensus application using the custom metric type custom.googleapis.com/opencensus/grpc.io/server/server_latency.

A heatmap with Cloud Trace exemplars displayed.

To view the details of a specific exemplar, select it. The displayed details include a graph that shows the trace spans. For more information, see Viewing trace details.

Show percentile lines on a heatmap chart

To hide or show the overlay of the 50th, 95th, and 99th percentile lines, on a heatmap chart, click Percentile lines in the chart toolbar. By default, the percentile lines are shown.

The following screenshot illustrates the chart with the percentile lines displayed:

A heatmap with Cloud Trace percentile lines displayed.

Show only percentile lines on a heatmap chart

To hide or show the heatmap chart, click Heatmap in the chart toolbar.

The following screenshot shows the chart when the percentile lines are shown but the heat map itself has been hidden:

A heatmap with Cloud Trace percentile lines displayed and heatmap hidden.

Highlight time series

You can examine individual time series by manipulating either the chart or its legend. This section describes how you can change the chart display so that one or more time series are highlighted while all other time series are dimmed.

Highlight a single time series

To highlight a single time series, do one of the following:

  • Place your pointer on the graph line at a specific point in time. As you move your pointer on the graph, each time it touches a graph line, that line is highlighted.
  • Click the selected checkbox in the corresponding row of the table legend or click the line in the graph. After you select a specific line, you can move your pointer without the selection changing.

    • To highlight a different line in the graph, select it.
    • To remove the highlight for a line, click in an unused area of the graph or expand the legend and then clear that line's checkbox.

For example, in the following screenshot, the halyard time series has been selected:

Display a rescaled chart with one line highlighted.

Highlight multiple time series

To highlight all lines between line-A and line-B, select line-A, press shift, and then select line-B.

To highlight multiple lines, do one of the following:

  • Press Control or Command, and then select the lines of interest from the graph.
  • In the legend, select the checkboxes for the lines of interest.

To highlight multiple time series, click the corresponding rows in the table or press shift while selecting the time series of interest.

To remove the highlight on a time series, select its row in the legend.

To remove all highlights, click in an unused area of the graph.

Set a reference time

To select a reference time on a graph, you set a pin at the reference time. An unset pin appears on the graph when you place your pointer on the numbers along the X-axis. The unset pin is a dim line with an oval at its base that displays a time and a pin symbol.

When you set a pin the following occur:

  • A blue line with an oval at its base appears on the graph. The base displays the reference time and a Dismiss button. To remove the pin, click Dismiss.
  • The legend field Value displays the value of the time series at the reference time.
  • When the chart is on a dashboard, a pin is set on every chart on the dashboard.

You can only set one pin on a chart and you can either set the pin at the current time or at a specific time:

  • To set the pin at the current time, click Value in the legend heading of the chart.

  • To set the pin at a specific time, place your pointer along the X-axis at that time, and then click the oval.

For example, the following screenshot illustrates a chart with a pin at 3:30 PM and a pointer at time 3:42 PM. The tooltip displays the timestamp that corresponds to the pointer position. The tooltip displays 440ms, which is the value of the time series server_latency at 3:42 PM. The legend displays 1.505ms, which is the value of the time series server_latency at 3:30 PM:

Display a chart with a time pin.

Change the graph resolution

There are multiple ways that you can change the resolution of a chart. For information about how to change the resolution of all charts on a dashboard, see Set the display period.

Expand a specific time interval

To magnify the graph in a specific time interval, do the following:

  1. Place your pointer in the graph area at one end of the time interval that you want to view in more detail.
  2. Drag your pointer horizontally to the other end of the interval. The drag action creates a dim region between two time selectors.

    After you release the pointer button, the graph is redrawn using the range of X-axis values that you selected. The Y-axis range is automatically adjusted based on the values in the time period you selected.

  3. Optional: Change the vertical resolution of the chart.

When you select a time period for any chart on a dashboard, auto-refresh is automatically disabled. To refresh all charts, click Auto-Refresh.

Expand the time resolution around a point in time

To magnify the graph around a specific point in time, do the following:

  1. Place your pointer in the graph area at the point in time that you want to view in more detail.
  2. To expand, or contract, the time axis, press Control or Command, and then use two fingers on a trackpad pointer or the scroll wheel on a traditional pointer.

Shift the time range

To shift the range of times being displayed, do the following:

  1. Place your pointer in the graph area at the point in time interval that you want to view in more detail.
  2. To display earlier or later data, press Control or Command and then select and drag your pointer.

Expand the vertical resolution

To magnify an interval of values, follow these steps:

  1. Place your pointer in the graph area at one end of the value range that you want to view in more detail.
  2. Drag your pointer vertically to the other end of the range to create. The drag action creates a dim region between two values on the Y-axis.

    After you release the pointer button, the graph is redrawn using the Y-axis range that you selected.

  3. Optional: Change the horizontal resolution of the chart.

When you select a range of values for any chart on a dashboard, auto-refresh is automatically disabled. To refresh all charts, click Auto-Refresh.

Reset the resolution

To reset a chart to its original state, click Reset zoom on the chart toolbar. The reset applies to all charts on a dashboard.

You can also click Reset zoom on the dashboard toolbar.

Set the display period

The chart can display data for a range of periods, typically from 1 hour to 6 weeks.

On a dashboard, you can also specify a custom display period on the dashboard toolbar. This display period applies to all the charts on the dashboard. You can set the display period for isolated charts, like those in Metrics Explorer, as well.

Changing the time range on a chart changes the range of data shown and can result in realignment of the time-series. For more information, see Alignment period.

To change the range, select one of the Time options:

Show the dashboard toolbar.

For a new project, data may not be available for all parts of the range.

The following screenshot shows two charts from a dashboard. The display period, on the X-axis, is shared across charts on a dashboard.

Show that all dashboard charts have the same X-axis.

Select dynamic or static data

Charts display data within a window of time. By default, this window advances, with “now” always at the right edge of the chart. The time selection determines the window into the past, for example, 1 hour. The data on the chart is dynamic; as new data is generated, it appears at “now”, and old data moves out of the window. By default, this behavior is enabled.

You can keep the time window from changing by turning off auto-refresh. This static option is useful when you want to study a past event. If you turn off Auto-Refresh, the button turns dim and is labeled OFF.

Dashboards provide a single Auto-Refresh button that applies all charts on the dashboard. When building a chart on the Metrics Explorer page, auto-refresh is always on.

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