Table of Contents
GridFTP is a high-performance, secure, reliable data transfer protocol optimized for high-bandwidth wide-area networks. The GridFTP protocol is based on FTP, the highly-popular Internet file transfer protocol. We have selected a set of protocol features and extensions defined already in IETF RFCs and added a few additional features to meet requirements from current data grid projects.
Features new in GT 4.0
- A new, complete reimplementation of the server.
- Support for striping.
- This new implementation will greatly ease new feature additions and modifications of the server (new commands, new data sources such as mass storage devices, etc.), maintainability, and resolves a licensing issue that was discovered.
Features that continue to be supported from previous versions
- GSI security: This is the PKI based, de facto standard security system used in Grid applications. Kerberos is also possible but is not supported and can be difficult to use due to divergence in the capabilities of GSI and Kerberos.
- Third-party transfers: Very common in Grid applications, this is where a client mediates a transfer between two servers (both likely at remote sites) rather than between the server and itself (called a client/server transfer).
- Partial file access: Regions of a file may be accessed by specifying an offset into the file and the length of the block desired.
- Reliability/restart: The receiving server periodically (the default is 5 seconds, but this can be changed) sends “restart markers” to the client. This marker is a messages specifying what bytes have been successfully written to the disk. If the transfer fails, the client may restart the transfer and provide these markers (or an aggregated equivalent marker), and the transfer will pick up where it left off. This can include “holes” in the file.
- Large file support: All file sizes, lengths, and offsets are 64 bits in length.
- Data channel reuse: Data channel can be held open and reused if the next transfer has the same source, destination, and credentials. This saves the time of connection establishment, authentication, and delegation. This can be a huge performance difference when moving lots of small files.
- Integrated instrumentation (Performance Markers).
- Logging/audit trail (Extensive Logging in the server).
- Parallel transfers (Multiple TCP streams between a pair of hosts).
- TCP Buffer size control (Protocol supports Manual and Automatic; Only Manual Implemented).
- Server-side computation (Extended Retrieve (ERET) / Extended Store (ESTO) commands).
- Based on Standards: RFC 959, RFC 2228, RFC 2389, IETF Draft MLST-16 , GGF GFD.020.
Other Supported Features
- On the client side we provide a scriptable tool called globus-url-copy. This tool can take advantage of all the GridFTP protocol features and can also do protocol translation between FTP, HTTP, HTTPS, and POSIX file IO on the client machine.
- We also provide a set of development libraries and APIs for developers wishing to add GridFTP functionality to their application.
Deprecated Features
- None
- Bug 1883: globus_ftp_control server does not decode ADAT properly.
- Bug 1928: Strange problems: Busy wait and address in use.
- Bug 2036: New gridftp, globus-gridftp-server, does not use globus_gss_assist_map_and_authorize
- Bug 2128: gridftp server checks ownership of hostcert after setuid
- Bug 2129: Gridftp logging levels (is 7>10?)
- Bug 2132: Server responds with "Valid credentials could not be found..."
- Bug 2452: non-striped gridFTP not working w/ round robin
- Bug 2463: striped server, small partial transfers hang
- Bug 2464: striped server to non-striped server doesn't work
GridFTP Server
- There are some small memory leaks, though they should not grow much.
- Threaded builds should work, but increased pollers may produce hangs (please report these).
- Some error responses are unclear.
- Bug 2547: gridftp config detach option doesn't work
- See the known issues section of source-trees/gridftp/server/src/TODO in the source installer for other issues.
GridFTP depends on the following GT components:
- Pre-WS Authentication / Authorization
- C Common Libraries
- XIO
GridFTP depends on the following 3rd party software:
- OpenSSL (version included in release)
Tested platforms for GridFTP
- i386 Linux
- ia64 Linux (TeraGrid)
- AIX 5.2
- Solaris 9
- PA-RISC HP/UX 11.11
- ia64 HP/UX 11.22
- Tru64 Unix
- Mac OS X
While the above list includes platforms on which we have tested GridFTP, it does not imply support for a specific platform. However, we are interested in hearing reports of success or bug reports on any platform.
Protocol changes since GT 3.2
- None
API changes since GT 3.2
- None
Exception changes since GT 3.2
- Not Applicable (GridFTP is not Java-based)
Schema changes since GT 3.2
- Not Applicable (GridFTP is not SOAP-based)
Click here for more information about this component.