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Kurt Biery, 03/27/2016 04:39 PM

Screen Snapshot Service

Sample Installations


The Screen Snapshot Service is logically composed of three parts:

  • Producers that periodically capture snapshots of a specified computer desktop and send the snapshots to a server.
  • A server that receives the snapshots from the producers, converts them to image files in an easily accessible format, and serves them to consumers.
  • Consumers that periodically fetch updated images from the server and display them to a user.

In the initial version of the system, these pieces have the following implementations:

  • The producer is a Java application that runs on the host that has the display(s) that are interesting to remote users. It is deployed with Java Web Start.
  • The server is a web application that runs inside the Tomcat Java application server.
  • The consumer is a combination of JSP pages and Javascript that are accessed with a web browser.


Please see the "Files" area of this project for tar files with built versions of the Snapshot Service.


  • snapshotWebapp_v1.6b2_java1.7.0_67.tar.gz
    • 26-March-2015
    • Added exit confirmation and general tool-top text to the snapshot producer at the request of CMS.
  • snapshotWebapp_v1.6b1_java1.7.0_67.tar.gz
    • 29-Oct-2014
    • Added the option to specify "controls=<on|off>&fittowindow=<on|off>" to the ShowImage.jsp URL to disable the controls and force the fit-to-window choice when running the snapshot client from a program, such as the large displays in the remote operations center.
  • snapshotWebapp_v1.5b19_java1.7.0_67.tar.gz
    • 10-Oct-2014
    • Updated the version of Java used to compile the webapp and producer.
  • snapshotWebapp_v1.5b18_java1.7.0_21.tar.gz
    • 19-Sep-2014
    • Updated the version of Java used to compile the webapp and producer.


As mentioned above, the snapshot server runs inside of Tomcat, and the snapshot producer runs using Java Web Start. As such, the first steps for installing the snapshot service boil down to installing Tomcat on your server PC and enabling Java Web Start on your producer hosts. (We don't have instructions for those in this Wiki yet.) After that, deploying the S3 webapp in Tomcat is mainly all that needs to be done.

The following Wiki pages may provide some useful information. They are records of the steps that we used when installing S3 for LArIAT and NOvA.

The following links provide some older instructions for installing S3, and they don't go into details of Tomcat or Java installation.

Installation Instructions (Linux)
Tips for JWS on Windows


  • Introductory talk presented at the 08-May-2007 LAFS meeting: PPT PDF
  • Diagram prepared for Alan's RT07 poster: PPT PDF
  • Introductory talk presented at the 23-Jan-2007 SiTracker meeting: PPT PDF

Read-only Access to the Git Repository

git clone