GridFTP is a protocol defined by Global Grid Forum Recommendation GFD.020, RFC 959, RFC 2228, RFC 2389, and a draft before the IETF FTP working group. The GridFTP protocol provides for the secure, robust, fast and efficient transfer of (especially bulk) data. The Globus Toolkit provides the most commonly used implementation of that protocol, though others do exist (primarily tied to proprietary internal systems).

The Globus Toolkit provides:

While the Globus Toolkit does not provide an interactive client, the GridFTP User's Guide does provide information on at least one interactive client developed by other projects.

If you wish to make data available to others, you need to install a server on a host that can access that data and make sure that there is an appropriate Data Storage Interface (DSI) available for the storage system holding the data. This typically means a standard POSIX file system, but DSIs do exist for the Storage Resource Broker (SRB), the High Performance Storage System (HPSS), and NeST from the Condor team at the University of Wisconsin – Madison. A complete list of DSIs is available [here]. If you need an interface to a storage system not listed here, please contact us. While we certainly cannot offer to write DSIs for every storage system, we can assist in the development, or if a broad enough community can be identified that uses the system, we may be able to obtain joint funding to develop the necessary interface.

If you simply wish to access data that others have made available, you need a GridFTP client. The Globus Toolkit provides a client called globus-url-copy for this purpose. This client is capable of accessing data via a range of protocols (http, https, ftp, gsiftp, and file). As noted above this is not an interactive client, but a command line interface, suitable for scripting. For example, the following command:

globus-url-copy gsiftp://remote.host.edu/path/to/file file:///path/on/local/host

would transfer a file from a remote host to the locally accessible path specified in the second URL.

Finally, if you wish to add access to files stored behind GridFTP servers, or you need custom client functionality, you can use our very powerful client library to develop custom client functionality.

For more information about GridFTP, see:

While globus-url-copy and GridFTP in general are a very powerful set of tools, there are characteristics which may not always be optimal. First, the GridFTP protocol is not a web service protocol (it does not employ SOAP, WSDL, etc). Second, GridFTP requires that the client maintain an open socket connection to the server throughout the transfer. For long transfers this may not be convenient, such as if running from your laptop. While globus-url-copy uses the robustness features of GridFTP to recover from remote failures (network outages, server failures, etc), a failure of the client or the client's host means that recovery is not possible since the information needed for recovery is held in the client's memory. What is needed to address these issues is a service interface based on web services protocols that persists the transfer state in reliable storage. We provide such a service and call it the Reliable File Transfer (RFT) service.

RFT is a Web Services Resource Framework (WSRF) compliant web service that provides “job scheduler"-like functionality for data movement. You simply provide a list of source and destination URLs (including directories or file globs) and then the service writes your job description into a database and then moves the files on your behalf. Once the service has taken your job request, interactions with it are similar to any job scheduler. Service methods are provided for querying the transfer status, or you may use standard WSRF tools (also provided in the Globus Toolkit) to subscribe for notifications of state change events. We provide the service implementation which is installed in a web services container (like all web services) and a very simple client. There are Java classes available for custom development, but due to lack of time and resources, work is still needed to make this easier.

For more information about RFT, see the documentation.