Internet Sharing

The iShare Project

About iShare

The iShare project develops Internet-sharing middleware and collaboration technology.
The overall motivation for iShare is to facilitate the interactions of computing resources, especially programs. These resources are geographically and organizationally dispersed on the Internet. iShare will build an infrastructure that allows dynamic and seamless resource sharing "on the net". It provides many features of systems that are also know as Information or Computer "Grids". iShare's distinguishing features are
  • it builds on an existing, widely-used Network Computing System - an operational Grid - the the Purdue University Network Computing Hubs. PUNCH has served its user community (with a focus on the Nanotechnology community) since 1995 and has over 1000 users in a dozen countries. Accordingly,
  • iShare's focus is on the user model of Global Information Sharing Systems, rather than on implementation technology. iShare uses existing standards, such as Web services and the NSF Middleware Initiative.
To the simple user, iShare appears as an environment that continually learns about software tools (computer applications), information sources (databases), and computers (or general information systems) that are available world-wide. It helps the user learn about these resources and facilitates access.

To the provider of the resource and the advanced user, iShare appears in the form of four basic concepts, shown in the following figure.


The iPublish capability allows the provider to post the availability of the resources and define access rules. iDiscover is capable of detecting iPublished resources and make the information available to the iRun function. iRun can remotely execute a program on an available machine, thereby mapping programs to machine resources. iCompose is able to use published resources as components and compose them into new entities, creating collaborative programs, machine cluster or coordinated databases.

iShare Release

This release provides a GUI and is portable for various platforms with J2SE 1.4.2 JRE/SDK installed. Download and try it. You can untar the package into any directory. An ishare_demo subdirectory will be created. Go to the directory and start "ishare.bat" on Windows or "ishare.sh" on Unix/Linux. Detailed instuctions could be found here. Features of the GUI-based iShare release include:

Try iShare in Java Web Start

Java Web Start is a framework developed by Sun Microsystems which allows Java applications to be started directly from the Internet using a web browser. Unlike Java applets, Web Start applications do not run inside the browser, and the sandbox in which they run does not have to be as restricted, although this can be configured. Using Web Start, users can easily access applications much as they would a web page--without a separate installation step. And, once a Java Web Start based application is installed, users simply click to run the application whenver needed. Users do not need to manually update applications because each time they launch an application, it is transperantly updated from the web--so they always use the most recent version available.

Before you try iShare in Java Web Start, please make sure that J2SE 1.4.2 JRE/SDK is already installed. (Since J2SE verion 1.4, Web Start has been included by default with the JRE and does not have to be installed separately.) Simply click here to start iShare. Java web start will automatically download all the jar files. The resources used by iShare, e.g., images and configurations, are downloaded and saved to a ".ishare_webstart" directory at the user's home directory. A script for starting iShare will also be downloaded to this home directory.

For first-time use, it takes about one minute to download the application and verify the Java code. For the verification, it will pop up a dialog asking if the user wants to trust the signed application distributed by "ParaMount Research Group". Please click on trust/accept the certificate. (The message is created by Java Web Start itself, since we do not use a publicly-issued certificate. We use our own certificate for flexibility in release management.) The download and verification only happen for the first time. After that, users can start the application via three different methods: The first two methods will check the latest updates automatically when lauching iShare. For the third method, users can check the updates through iShare's menu: "Help--->Update iShare".

  FAQ

1. How to set up my own publish web site?

Step 1. Choose a url as the publish site, e.g. http://www.abc.edu/iShare/.

Step 2. Download and untar the cgi script. It will create a "cgi-bin" directory. Put this directory under your own url, e.g. http://www.abc.edu/iShare/cgi-bin.

Step 3. Enter the cgi-bin directory and change the privilege with " chmod a+s * ".
   
Step 4. Establish a new directory with the name "publish" under your url and put an empty file "list" under this new created directory, e.g. http://www.abc.edu/iShare/publish/list.

Now, you have set up your own publish site. When you use iShare to publish your own script, a dialog will pop up asking to choose the descriptor file and  a url. Here, you could input your own publish site, e.g. "http://www/abc.edu/iShare/" , or use the default iShare web site.

2. How to publish and run interactive applications?

Currently, iShare supports interactive applications with VNC-4.0 and SSH. When publishing an interactive application, set the "application interface" as "graphic interface" or "command-line" and a VNC server should be available on the execution platform. You could download VNC from the RealVNC web site. Remember to include the required path to start VNC server as "environment variables" when publishing the application. iShare already includes a VNC viewer. So, there is no need to install that on an iShare client.

3. When I tried to run iApply the first time, it asked me to input a passphrase for a public key. What does that mean?

In iShare, SSH is used to communicate with a remote machine. It uses public key for authentication. A pair of private/public keys is generated when you  ran iApply the first time. The passphrase is to encrypt your private key, so that even if others get your private key, they can't use it.

4.  When using iRun, I had to input the password or passphrase several times...

This happens because iApply fails to set up the public key authentication. To solve this problem, you can try the following commands in your unix shell,
eval `ssh-agent`
ssh-add
Apply -d
iApply

5. When will I be asked to input the passphrase again?

When you reboot your machine and logon again, you'll be asked to enter the passphrase. If your machine is on NSF and you have the same home directories on several machines, you may be asked to input your passphrase only once for each machine. (This is because a ssh-agent will be started on your account at each machine.)

Refrences

Contact us

Thanks for trying iShare. If you have any question, suggestion and comment, send me an email.

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