Diagnosing¶

A diagnostic allows you to inspect the state of a Virtual DataPort Server in the past, by browsing graphically its logs. This can be extremely helpful when you have detected a malfunction in its behavior and want to find its cause.

The Diagnostic & Monitoring Tool displays the diagnostic information collected in logs using graphs and tables. As you will see, the interface is similar to the monitoring of a server, but with historical data instead of real-time data.

The figure below shows an example of a graph with three series. Besides the series data, the graph may contain information about Virtual DataPort startups (red milestones) and Denodo Monitor session startups (green milestones). These milestones are surrounded by blurred regions where there is no information to show, because either the Denodo Monitor or the Virtual DataPort were stopped.

Diagnostic information presented in a graph¶

The header of the graph contains its name and a set of icons to operate with it. You can click on the header and the graph will collapse. Moreover, you can zoom in on a region by selecting it with the mouse.

The icons in the header of a graph are:

• : Enabled after selecting a region in the graph, removes the zoom and displays all the data available for the graph.

• : Enabled after selecting a region in the graph, creates a new diagnostic interval for the selected period.

• : Displays a menu with options to configure the graph:

  • Enable tracking: If selected, you can pass the cursor anywhere in the graph and you obtain the current measure for all the series at this exact moment. If cleared, you only obtain the measure of one series when you place the cursor over it.

  • Show points: If selected, the series in the graph will show a point at every moment a data was registered in the log.

• : Unfolds a menu where you can choose which series the graph will display.

Some operations require that you select a specific date. You can do this by clicking directly in the graph. Take into account that if the Enable tracking option is selected, you can click everywhere you want in the graph. Otherwise, you should click on one of the series.

Diagnostic information presented in a table shows an example of diagnostic information displayed as a table. Blurred rows indicate that the logs do not contain enough information about the element to be sure if it has finished or not and, in case it contains an end time value, it will be an approximate one.

Diagnostic information presented in a table¶

Again, the header shows the name of the table and a set of icons to operate with it. You can click on the header and the table will collapse.

The icons in the header of a table are:

• : Unfolds a menu where you can choose which fields the table will display.

• : Displays a dialog to define a condition to filter the contents of the table. The section Monitoring explains how to create a filter.

Diagnostic tables also support sorting by a certain field or set of fields. Click on the name of a field to sort the content of the table by that field. Click on another field while pressing the CTRL key in your keyboard and you will add a second sorting field.

Double-click on a row, or right click and select View Row, to see all its fields. This is useful if you configured the table to display only some fields.

The information dialog shows the values for all the fields of a row¶

To open a diagnostic or a diagnostic interval, double-click its name in the tree area. The Diagnostic & Monitoring Tool will open a new tab in the working area with the diagnostic information of that node.

Diagnostic or diagnostic interval tab¶

The diagnostic information is displayed respecting the dates in the logs; no time zone transformation is performed. Thus, you will work as if you were in the time zone of the server you are diagnosing.

The tab of a diagnostic or diagnostic interval presents the following set of icons:

• : Shows information about the current diagnostic or diagnostic interval.

• : Reloads the whole tab as if it was opened again.

• : Opens the tab in a new window.

• : Closes the tab.

The tabs with diagnostic information about the whole server (resources, requests, threads…) are fixed and cannot be closed. However, you can open new tabs that display parameterized information, like the requests of a particular session for instance. Notice that these tabs count with the following icons:

• : Shows all the information about the parameter of the tab.

• : Allows you to change the name of the tab.