Teragrid is the National Science Foundation terascale computing infrastructure. It consists of over a dozen clusters all over the US, numerous web resources and consulting services. (UMBC's clusters are not part of Teragrid.) Researchers can get access to those resources by submitting a Teragrid allocation request, which is processed much like a grant application. The best explanation of Teragrid's purpose and capabilities is given on its about page:

TeraGrid is an open scientific discovery infrastructure combining leadership class resources at eleven partner sites to create an integrated, persistent computational resource.

Using high-performance network connections, the TeraGrid integrates high-performance computers, data resources and tools, and high-end experimental facilities around the country. Currently, TeraGrid resources include more than 750 teraflops of computing capability and more than 30 petabytes of online and archival data storage, with rapid access and retrieval over high-performance networks. Researchers can also access more than 100 discipline-specific databases. With this combination of resources, the TeraGrid is the world's largest, most comprehensive distributed cyberinfrastructure for open scientific research.

TeraGrid is coordinated through the Grid Infrastructure Group (GIG) at the University of Chicago, working in partnership with the Resource Provider sites: Indiana University, the Louisiana Optical Network Initiative, the National Center for Atmospheric Research, National Center for Supercomputing Applications, the National Institute for Computational Sciences, Oak Ridge National Laboratory, Pittsburgh Supercomputing Center, Purdue University, San Diego Supercomputer Center, Texas Advanced Computing Center, and University of Chicago/Argonne National Laboratory,

For more information about Teragrid, see these links:

• http://www.teragrid.org – the main website for Teragrid.
• http://www.teragrid.org/userinfo/getting_started.php – the "Getting Started Guide" for those new to Teragrid
• http://www.teragrid.org/userinfo/access/allocations.php – the step-by-step guide to getting an allocation, target towards first-time users.
• http://www.teragrid.org/userinfo/hardware/index.php – details about all Teragrid resources. For resources on a specific cluster, see the two pull-down menus under "Allocatable Resources."
• help@teragrid.org – possibly the most useful Teragrid resource. Teragrid users and potential users should send any questions to this email address.
• https://pops-submit.teragrid.org/ – the website of the Partnerships Online Proposal System (POPS) to which one submits Teragrid resource allocation requests
• http://www.teragrid.org/userinfo/access/pops_guide.php – the website that describes how to submit resource allocation requests.

The rest of this section describes the steps in the process of obtaining an account on Teragrid clusters, and CPU time on those clusters. This information is not intended to replace the information on the Teragrid website, but rather to supplement it based on the experiences of UMBC researchers who have received allocations. If you have received an allocation, please send an email to user support informing us of your experiences so that we can add to this webpage and help future users.

Getting Access to Teragrid

In order to get an account on a Teragrid cluster, one must submit an allocation request, which is something much like a grant application. There are three different types of allocation requests, and they differ in the maximum size and the delay before you receive the allocation. The size of the allocation is given in Service Units (SUs) which are essentially cpu-core-hours, though the definition varies slightly between clusters:

See this page for the most recent version of that chart and for more details:

http://www.teragrid.org/userinfo/getting_started.php?level=new_to_teragrid

Writing your Allocation Request

This section will give you a broad overview of the process of submitting an application and it will describe some techniques and tactics that may help you. Submitting your allocation request is done via the Teragrid Partnerships Online Proposal System (POPS):

https://pops-submit.teragrid.org/

and for details of the process of getting a POPS account, creating an allocation request and submitting it, see this page:

http://www.teragrid.org/userinfo/access/pops_guide.php

This section will not cover the exact details of submission, but the above linked websites will.

When you write your allocation request, you must specify which clusters you wish to have an account on, and how many SUs you wish to have on each cluster. Instead, if you want, you can ask for a wide roaming allocation which gives you CPU-hours that you can apply to any Teragrid cluster. Wide roaming developmental allocations are limited to 30,000 SUs. Larger wide roaming allocations are highly unusual, but wide roaming developmental allocations up to 30,000 SUs are fairly common.

If you apply for a large allocation, you are more likely to have it awarded if you provide good support for your estimate of the number of SUs you say you will need. The best way to provide support is to run scaled-down test versions of your program on the clusters on which you will request access. In order to do that, you first need to get a developmental allocation. Thus, the most reliable path to a large Teragrid grant is the following:

1. Apply for a wide roaming developmental allocation of up to 30,000 SUs.
2. Use that allocation to test your program on a variety of Teragrid clusters, and find out which ones will run your program, and which ones make the best use of SUs.
3. Determine the number of SUs full-scale runs of your programs will take. Depending on your program, there may be no perfect way of doing this, but try to give the most objective estimate you can.
4. Write a Research Allocation Request that establishes the scientific value of your research, and provides a well-supported estimate of the number of SUs you need on each cluster.

Depending on your application, you may find that splitting various aspects of your calculation between several Teragrid clusters will make better use of your Service Units. If the difference is substantial, you may want to consider writing an application that requests a certain number of SUs from each of several clusters.

Using your Allocation

The process of starting to use your allocation varies from year to year, and also varies from cluster to cluster. The Teragrid personnel at help@teragrid.org can answer any of your questions. In addition, you can inquire about or access most aspects of your allocated Teragrid resources using the Teragrid User Portal. Detailed information about the user portal can be found here:

http://www.teragrid.org/userinfo/portal.php

and that page includes a good description of the user portal:

The TeraGrid User Portal is a Web interface for making TeraGrid account management easier, for getting information about TeraGrid resources, and for accessing many of the existing TeraGrid services in a single place. All new users will receive a "New User Form" via U.S. postal mail that contains a portal username and password along with their other TeraGrid system account usernames and passwords.

That same webpage also contains instructions on how to perform various actions on the user portal. The process of setting up your initial account on the clusters varies wildly from cluster to cluster. There are a few commonalities, though.

You can log in to any Teragrid cluster via the Teragrid User Portal. To do that:

1. Log in to the Teragrid User Portal.
2. Click on the "My Teragrid" tab.
3. Click on "Accounts" (just below and to the right of "My Teragrid").

You should see a list of the Teragrid clusters.

In the Teragrid User Portal, clicking on blue text will bring you to a page that logs you in to the corresponding cluster. It logs you in using an SSH program that runs in your web browser (via a Java applet). Some of the lines may say "no account." If you don't have an account on a cluster that you should be able to access, or if you have any other troubles, contact help@teragrid.org.