5.2 Working with Globus

The Globus software provides a well-defined set of protocols that allow authentication, data transfer, and remote job submission.

Authentication is a mechanism by which an identity is verified. Given proper authentication, authorization to use a resource is required. Authorization is a policy that determines who is allowed to do what.

5.2.1 Globus Protocols

Condor uses the following Globus protocols. These protocols allow Condor to utilize grid machines for the execution of jobs.

GSI

The Globus Toolkit's Grid Security Infrastructure (GSI) provides essential building blocks for other Grid protocols and Condor-G. This authentication and authorization system makes it possible to authenticate a user just once, using public key infrastructure (PKI) mechanisms to verify a user-supplied grid credential. GSI then handles the mapping of the grid credential to the diverse local credentials and authentication/authorization mechanisms that apply at each site.

GRAM

The Grid Resource Allocation and Management (GRAM) protocol supports remote submission of a computational request (for example, to run program P) to a remote computational resource, and it supports subsequent monitoring and control of the resulting computation.

GASS

The Globus Toolkit's Global Access to Secondary Storage (GASS) service provides mechanisms for transferring data between a remote HTTP, FTP, or GASS server. Condor-G uses GASS to transfer the executable, stdin, stdout, and stderr between the submission local and the remote resource.