Zoomdata Version

Setting Up the Screenshot Feature (for CentOS)

OVERVIEW

The screenshot feature provides periodic snapshots of your saved dashboards on Zoomdata's Home page.


Figure 1

SETUP

The Screenshot functionality requires the Firefox browser and the Xvfb file installed within the Zoomdata Server.
The steps below have been tested on Firefox v45.x.

Zoomdata only supports 64-bit version of Firefox.
  1. Check the version of Firefox that is running on your machine.
    firefox -v
  2. If you don't have it installed, run the following command to install Firefox v45.7.0 with Xvfb service into your Zoomdata Server:
    sudo yum install -y xorg-x11-server-Xvfb.x86_64 firefox-45.7.0
  3. Modify zoomdata.properties file to enable and setup the Screenshot functionality.  In addition to enabling the Screenshot functionality, you can also set the time period for capturing screenshots of your visuals to be displayed on your Home page.
    • To create screenshots in the background, set the following option to true :
      screenshot.daemon.enabled
    • Specify which types of screenshots you want to enable:
      screenshots.dashboards.enabled - set this option to true if you want to enable capturing and displaying the screenshots for the dashboards.


Figure 2

  • Specify the frequency rate when the screenshots are refreshed by configuring the following property: screenshot.daemon.schedule.rate= # h The default timeframe is every 6 hours, but you can set your own time period (in hours) by replacing # with your desired timeframe.

If needed, you can configure the settings as follows:

screenshot.daemon.enabled

screenshots.dashboards.enabled

Result
true true
  • Screenshots are created in background.
  • Screenshots can also be created manually by sending cURL calls.
  • Screenshots are shown on the Home page
false true
  • Screenshots are created only one time, when the dashboard is saved.
  • Screenshots are not created in background.
  • Screenshots can be created manually by sending proper cURL calls.
  • Screenshots are shown on the Home page
false false
  • Screenshots are not created in background.
  • cURL calls to create screenshot on demand take no effect.
  • Screenshots are replaced by the default thumbnails
true

false

  • Screenshots are not created in background.
  • cURL calls to create screenshot on demand take no effect.
  • Screenshots are replaced by the default thumbnails
  1. Restart the Zoomdata service to ensure the changed Firefox program has been enabled.
    For the appropriate Linux command line (for CentOS v6, v7 or Ubuntu v14, v16), refer to the article Restarting Zoomdata Services .

Screenshots may not immediately populate your home screen, but is available based on the 'schedule.rate' that you set.

known issue

If you have updated your CentOS system,  the screenshot feature may stop working. This occurs due to the new Firefox versions that are not supported by Zoomdata. To ensure that this is the cause of the issue, check the current browser version:

firefox -v

If the Firefox version is 46+, you need to remove the current version and install an earlier one (Firefox v45.6.0). To do this, perform the following steps:

  1. Remove current version of Firefox:
    yum remove firefox
  2. Install Firefox:
    yum install firefox-45.7.0
  3. Check that Firefox has been installed correctly. The version of the installed Firefox will be returned.
    firefox -v

UPGRADE NOTES

After upgrade to v2.5, by default, the screenshots on the Home page may look different. This occurs due to the change of the screenshot aspect ratio. In v2.5 the default screenshot aspect ratio is 16:9, while in previous releases it was 3:4. To make the screenshots look correct, make sure that the screenshot.daemon.enabled property in the zoomdata.properties file is set to true. After this you can update the screenshots in one of the following ways:

  1. Modify the screenshot.daemon.schedule.rate property and set more frequent refresh rate.
  2. Execute the cURL call to update a screenshot for a specific dashboard.
  3. Execute the cURL call to upload a custom image for a specific dashboard. Otherwise, the screenshots will be updated when the refresh screenshot procedure runs according to the configured refresh rate.