Explore charted data

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.

This page describes how to use the chart toolbar and how to interact with the charted data.

For information about creating charts, see the following:

The chart toolbar

The chart toolbar, when available, provides a set of options that apply only to the chart. When the dashboard toolbar contains the same option, a setting applied by using the chart toolbar overrides the dashboard toolbar setting:

  • Toggle Legend

    Click this button to hide or display the legend. For more information, see Show and hide legends.

    When the chart width isn't sufficient to display the legend toggle in the chart's toolbar, this option is accessible by using chart's Other options menu.

  • Fullscreen

    To enlarge a single chart on a dashboard, click Fullscreen.

    To exit full-screen mode, click Esc.

  • Reset zoom

    Click this button to revert a chart's zoom operation. The reset applies to all charts on a dashboard.

  • Other options

    The context determines options available for a particular chart. For example, the edit option isn't available for charts on a predefined dashboard.

    Click this button to do any of the following:

    • Change the Chart mode.
    • Edit the chart.
    • Download a PNG image of the chart.
    • View the chart in Metrics Explorer.
    • View associated logs in the Cloud Logging Viewer. See Viewing logs for information about using the Cloud Logging interface.

      This option is available when an alerting policy is configured to monitor any of the metrics shown by the chart.

For distribution charts, the chart toolbar might include additional buttons that you can use to change the view of the chart.

  • Trace exemplars

    Click this button to hide or show Cloud Trace exemplars. This button is displayed only when the data can contain an exemplar. 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.

    When Cloud Trace exemplars are displayed, select a specific trace to open the trace details pane. The details include a waterfall graph that illustrates the trace spans and a table. For more information, see Viewing trace details.

  • Percentile lines

    Click this button to enable or disable the overlay of the 50th, 95th, and 99th percentile lines. By default, the percentile lines are displayed.

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

    A heatmap with Cloud Trace percentile lines displayed.

  • Heatmap

    Click this button to hide or show the heatmap.

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

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

Highlight chart data

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 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. If you want 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. If you click Auto-Refresh, then the new data is gathered and all charts are redrawn.

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. If you click Auto-Refresh, then the new data is gathered and all charts are redrawn.

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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