This document should serve following purposes:

  • provide a hub for all documentation regarding running applications on the OSG
  • provide link to first step documents for storage and compute elements
  • provide links to advanced topics such as pilot based job submissions / glideinWMS factories
  • provide contact information for grid users developing grid applications

Developing Grid Applications

About this Document

hand This document is for grid users working with grid applications. Every user must be associated with a registered organization (called a VO). Many large VOs (such as ATLAS and CMS) already have extensive user documentation; these pages are primarily oriented at users of smaller VOs who might be porting their own or community applications to the OSG.

These pages first introduce the primary OSG concepts, then dives into the nuts and bolts of building (or porting) an application to the grid by showing demonstration applications of increasing complexity. Both job management and data management are covered.

About the Open Science Grid

  • What is OSG? This page introduces the "big-picture" concepts of what the OSG is, what it is not, and what it tries to achieve.
  • What are VOs? Virtual Organizations - "VOs" - are an important organizational concept for the OSG; this page introduces VOs for the end-user.

About Certificates and Security

How a user is authenticated (identified) and authorized to access Grid resources.

  • What is a certificate? A digital certificate is like a passport for the grid. This page introduces them to new users, and includes links for getting your own certificate.
  • Get a Certificate Instructions on how to get a certificate.
  • How do you get access to a site? The certificate provides you with an identity - but doesn't give you access rights to a site! This page describes how one gets authorized at an OSG site.

OSG Client Software

The following sections provide information on job and data management on the OSG and techniques used to develop and run grid application successfully. Please install the OSG Client Software before you proceed.

Running Jobs

There are many steps and questions about accessing Compute Elements to run jobs.

Data management

Data management is difficult on the grid. Unlike running jobs, where a consensus approach is beginning to appear, there are many techniques for data management. Some of them scale up well to hundreds of TBs a day, but scale poorly to opportunistic jobs.

The most common approach is to use a get/put method - they download input from a remote endpoint to the scratch area. The jobs run, and write output to the scratch area. After computation part of the job is finished, the result upload is uploaded to a remote endpoint.

Two common approaches to staging in data are via HTTP (many sites have local caches) or a protocol called SRM.

The de-facto way to save output is through SRM.

Advanced Topics

Beyond "traditional", basic job handling, there is a wide variety of specialized topics for using the OSG. Here are a few which may appeal to advanced users:

How to get Help?

References

Comments

A lot of content is similar to UsingTheGrid MarcoMambelli 13 Oct 2011 - 17:41

-- RobertEngel - 30 Aug 2011

Topic revision: r24 - 25 Aug 2017 - 16:46:27 - BrianBockelman
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