AMirD Demonstration

AMirD comes with a demonstration setup that allows you to verify that it is working properly and to show how it works. The demo1 directory contains all files needed to run the demonstration.

What it Does

The demonstration allows you to set up a server (the exporter) and a client (the importer) such that all files on the exporter's file system will be mirrored on the importer's file system. To better illustrate what is happening, the files being transferred are images (jpeg files), and a browser is run at the client and server to show the current state of the files.

When started, the server will show a web page with a matrix of balls. Every 20 seconds a random ball will be modified to a random color:

Server Initialized One Ball Changed

These changes will be reflected in the client's file system and shown on the client's web browser:

Client Gets Change

Due to latencies in transmission and display, the client display will always lag the server's.

Running the Web Browser

Note that it is not necessary to run a web browser to run this demonstration. The browser only provides a visual aid to see that files are changing. A directory listing of the client's and server's files will provide essentially the same information but with less visual impact.

This demonstration uses the Opera web browser, which is run automatically at startup. If you would like to use a different browser, modify the amird-2.0.7/demo1/server/run_server and amird-2.0.7/demo1/client/run_client scripts to do so. This browser was chosen because it automatically re-loads images referenced by the html code. If you use a different browser it may be necessary to set options or re-start it to refresh the screen properly.

Set Up and Execution

The client and server must be run in different windows. They may be run on the same machine or different machines.
  1. ANTI_HOME

    The ANTI_HOME environment variable must be set up prior to starting the server or client. Details on setting this up are in the installation instructions.

  2. Starting the Server

    To run the server, change directory to amird-2.0.7/demo1/server, and execute the following command:

    % ./run_server The server will start the web browser to show the files that it is exporting. It will also start the Antigone scope, which allows a more detailed monitoring and control of Antigone. The graphical user interface looks like this:

    It is not necessary to run the scope for the sake of this demonstration, and the window may be ignored or shut down.

  3. Starting the Client

    In a different window, possibly on a different machine where AMirD has been installed, start the client by changing directory to amird-2.0.7/demo1/client and executing the following command: % ./run_client The client will start another browser window reflecting the state of its file system. It will also start another Antigone Scope.

Troubleshooting

  1. No Web Browser or Scope

    If neither the web browser nor scope appear, it may be because the DISPLAY environment variable is not set up. Try running xclock (a standard X-Window program) to verify that you have access to the windowing system.

  2. No Web Browser

    Try running the web browser from the command line. Errors it reports should indicate the nature of the problem. Again, it is not necessary to run a browser for this demonstration, you can instead use a directory listing program such as ls to observe the files changing.

  3. No Scope

    Make sure that the ANTI_HOME environment variable is set up. If it is, then there is probably a problem with the tcl/Tk installation on your machine.

  4. Client Does not Get Files

    Try running one of the Antigone programs such as simple or a2pipe to verify basic Antigone functionality. By default, this demonstration uses multicast uses symmetric multicast for communications between the client and server. Make sure that your system is configured to support symmetric multicast.