Userfaq

From UC Grid Wiki
Jump to: navigation, search

FAQ

Why should I use the UC Grid?

The UC Grid provides a place where you can sign on once to use any of the clusters that you have access to. From within a web browser you can:

  • Submit jobs without writing script files
  • Access any cluster from anywhere (no installing SSH programs on a borrowed computer)
  • View and move data files graphically
  • Use some graphical X-windows applications from a web browser.

Do I get access to all of the machines listed under resources?!

No, you can only submit jobs to machines you have an account on.

However, there are some shared resources available in the 'Pools'. These are open to anybody on UC Grid.

What are the URLs (web site addresses) of the various Grid Portals in the University of California System?

  • UC System Wide -- portal.ucgrid.org
  • UCLA -- grid.ucla.edu
  • UCSB -- grid.ucsb.edu
  • UCI -- grid.nacs.uci.edu

How do I apply for Grid access?

You can apply to use the Grid only at your Campus Grid Portal. You cannot apply at the UC Grid Portal. Go home page for the Grid at your campus and click either on the "Apply for Grid Access" link in the bottom or the Login box in the upper right on the "Apply" link under the "Welcome" tag in the upper left. Each campus Grid Portal has its own way of validating new users. For those campuses with campus-wide authentication, that authentication will be used; for those campuses without campus-wide authentication you might have to prove that you have a login id on a cluster that is participating in the Grid by entering your login id and password for that cluster.

What kinds of Grid users are there?

There are two kinds of Grid users, Cluster Users and Pool-Only Users. A Cluster user has a login id on at least one cluster that is participating in the Grid. A Cluster user may directly use any cluster that user has access to and may additionally use the resource pools. A Pool-Only user can use cluster resources that have been contributed by the various clusters to a resource pool. Work performed by a Pool-Only user can happen on any of a number of clusters.

What if I am a Cluster User and my login ids differ on the various clusters

This isn't a problem, you just choose a Grid username you want, and it will be automatically mapped to your login id on a specific cluster whenever you use that cluster. Having a single Grid Username and password is very convenient, especially if you have multiple login id/password combinations on the clusters themselves.

How do I get around in the Grid Portal?

You navigate via the tabs on the top. Each tab usually provides a number of related services. These are listed in the bar immediately below the tab. Click on the one you want.

What resources are available on the clusters in the Grid?

Click on the resource tab to find out! Also, check out JobServices -> Applications for precompiled applications that you can start directly. For X-based programs, look under the Interactive tab.

How about if I still need/want a command line?

You can open a SSH window (without having SSH installed even!) under the "Interactive" tab or click on "Interactive Apps" under the "Interactive" tab and then request an XTerm. In order to use these interactive services, you will have to have a Java plug in installed in your web browser.

How do I submit a job?

To run your own program, click on "Job Services" tab, and then on "Generic Jobs". Pick a cluster from the pull down menu to run it on, give it a name, executable (you can click on the Folder icon to use the Grid Data Browser), select if it's a serial or an MPI job, specify the number of CPUs and max CPU time, and click submit! That's it! How to submit your job?

To run a commonly-used application, click on the "Job Services" tab and then on "Applications" and select the application from the list at the left. Most of the information you have to supply is similar to the "Job Services" form. How to submit an application job? Some applications also include an "Input Generator" form which will allow you to create an input file. If your application does not have an "Input Generator" you will need to have an input file for the application and supply appropriate arguments for the application. For more information on the "Input Generator", see AppForm FAQ.

How do I monitor a job's status?

Click on the "Job Services" tab and then "Job Status". This shows your submitted, running, and completed jobs. You can look at the std.out and std.err files produced by the jobs from here too. Note that it may take a minute for a job that's been submitted to show up under "Job Status".

How do I use the Data Manager?

There are currently two Data Managers available: the Data Manager and the AJAX Data Manager. Both of them have the same functionality. While the AJAX Data Manager is more seamlessly interactive and has a user interface which more resembles a PC desktop, it does not work on all browsers (it will not work with Opera). For the Data Manager, click on the name of a file to select that file or on the folder icon next to a directory name to select a directory and then click on the function from the list at the top that you want to perform on that file or directory. For the AJAX Data Manager use the menu's at the top to perform functions on selected files. Icons appear below the menu bar for commonly used functins.

I can't change directory into a directory with the Data Manager!?

You need to click on the icon of the folder to 'cd' into it, don't click on the directory name.

How about visualizing files?

Once you select a file in the Data Manager, you will get additional options up near the top, e.g. view, edit, etc. Click on "Visualize". If it knows what kind of file it is, it will open another window with a visualizer, otherwise it will ask what kind of file it is. Your web browser must be Java enabled for the visualitions to work.

Depending on your Grid Portal, you may also be able to start X-based applications from the Interactive tab.

Can I use the UC-wide Grid Portal?

Yes - once you have a Campus Grid Username, you can also use the UC-wide Grid Portal. Not all University of California campuses have joined the UC Grid yet, but ultimately we hope you will be able to access resources at any of the ten campuses from there!

Where can I get more help?

There is a help button shaped like a question mark in the left side of the frame on every Grid Portal page. Click on the question mark for a brief help about using that page. Additional documentation is linked to from the links on the right side of the Grid Portal Home page. You can get to the complete University of California Grid documentation at www.ucgrid.org.