Graph

Viewing Measurement Data

Data collected from Measurement Jobs can be plotted on graphs on demand. Users can configure their own graph settings for available time series, and can share these graphs with other users of Netsight.

Sources of Graphs

There are two ways to view data in Netsight either go to one of the pages with a graph list or use the Netsight Explorer to find an item that can be graphed.

There a five graph pages, these are all in the "Graphs" menu in the Menu Bar. These pages are:

To use explorer right click on a graphable item and use the context menu to graph the selected item. For:


Viewing Graphs

On the View Graphs page, you can see the data for your selected graphs plotted on one or more charts. Charts are plotted with time along the x-axis and the measurement value on the y-axis. All charts on the page are shown with the same x range. The x range can be changed with the controls at the top of the page:

The system automatically sets the scale for the y-axis for each graph. You can override this by entering minimum and maximum values in the box to the bottom-left of each graph and clicking the Apply button icon. Click Reset button to reset the graph to the default Y-range. You can also choose to use a logarithmic scale for the y-axis by checking the "Use logarithmic y-axis" box at the bottom left of each chart.

Summary statistics for the time series on a chart are shown in the box to the right of each chart. This shows maximum, minimum and average readings for each time series plotted. Also shown is the value of the last measurement included on the graph. Please note that this is the last actual measurement that is on the graph, and may not exactly equal the position that the interpolation line leaves the leading edge of the graph.

Many parts of the Netsight link to the View Graphs page to display one or more graphs. If you navigate to the page by the menu link you can select which graphs to show by selecting from your saved graphs in the list at the bottom of the page, and clicking "Add". A graph may be removed from the page by clicking the cross in the top right corner of the graph. The selection of graphs you put on the page will be restored when you next enter the view graphs page from the menu item.

Understanding the data plotted by Netsight

Whenever you view a graph, you may be viewing data that has Netsight has already collected and summarised over various time periods. If you are zoomed in sufficiently close enough, Netsight will plot raw data on the graphs. As you zoom out, Netsight may instead choose to plot summary data instead of the raw data. This is done for efficiency purposes — it would take too long to plot a graph over a timescale of a month using all that month's raw data.

This summary data is data that Netsight has averaged over certain time periods. These average values are pre-calculated as Netsight gathers the data. Netsight averages data over the following time periods:

This can cause surprising behaviour in some situations. Suppose you are investigating a short outage, and you are viewing a Ping Response graph that shows the Ping Response dropping to 0%. If you are zoomed in close enough to see the raw data, you will see the graph drop to zero. As you progressively zoom out, Netsight will at some point switch from plotting the raw data to plotting the 4-minute average data. If the outage was short (say, about a minute), the minimum Ping Response around the outage time may jump from 0% to about 75%.

Exporting Data

To see the data used to build the graph, you can export a CSV file of the data to your computer. To start this, click "Export" on the View Graphs page under the graph whose data you wish to export.

If the graph is showing raw data, the download to your browser will begin immediately. Otherwise, you will be given the option of exporting data at the same summary level, or one or two levels finer as are available. Downloading then begins once you select the desired summary level and click Export.

If an error has occurred during the measurement of a data point, the background of the graph is shaded red. For example if an SNMP request times out or a ping request gets dropped, this will show as an error on the graph. When you do an export, the details of the errors for the exported interval will be shown, but only if you are exporting raw data. If you can see an error region on your graph, but an export does not give you its details, try zooming in on the error and repeating the export.


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