Note
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The Grid Community Toolkit documentation was taken from the Globus Toolkit 6.0 documentation. As a result, there may be inaccuracies and outdated information. Please report any problems to the Grid Community Forums as GitHub issues. |
Component Overview
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.
Feature Summary
Features new in GCT 6.2:
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None.
Features that continue to be supported from previous versions
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Chrooting GridFTP server
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Synchronize datasets
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Improved failure restart capability in globus-url-copy
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Stall detection
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Load balancing in globus-url-copy
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GridFTP over UDT
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SSH security for GridFTP control channel
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Running the GridFTP server with GFork GridFTP
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Multicasting / Network overlays (EXPERIMENTAL)
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Netlogger’s bottleneck detection for GridFTP transfers (EXPERIMENTAL)
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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.
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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).
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Cluster-to-cluster data movement or Striping: GridFTP can do coordinated data transfer by using multiple computer nodes at the source and destination.
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Partial file access: Regions of a file may be accessed by specifying an offset into the file and the length of the block desired.
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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.
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Large file support: All file sizes, lengths, and offsets are 64 bits in length.
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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.
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Integrated instrumentation (Performance Markers).
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Logging/audit trail (Extensive Logging in the server).
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Parallel transfers (Multiple TCP streams between a pair of hosts).
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TCP Buffer size control (Protocol supports Manual and Automatic; Only Manual Implemented).
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Server-side computation (Extended Retrieve (ERET) / Extended Store (ESTO) commands).
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Based on Standards: RFC 959, RFC 2228, RFC 2389, IETF Draft MLST-16, GGF GFD.020.
Other Supported Features
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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.
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We also provide a set of development libraries and APIs for developers wishing to add GridFTP functionality to their application.
Deprecated Features
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None
Summary of Changes in GridFTP
New Features: GridFTP
-
Highlights
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None.
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-
Other New Features
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None
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Improvements: GridFTP
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None.
Fixed Bugs for GridFTP
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None.
Known Problems in GridFTP
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GRIDFTP-178: Hanging server processes with GT5.0.4 striped GridFTP servers
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GT-2: GUC will treat directory as if its a file for the purpose of sync comparison
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GT-4: Can’t build gridftp server with alternate CC, needed by LTA
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GT-5: globus-url-copy doesn’t pipeline url input from a file
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GT-6: GridFTP installation on OpenBSD 4.9
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GT-7: Issues with netlogger style logs
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GT-8: globus-url-copy -rst … -st … segfault if the options are not correctly synchronized
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GT-10: Problem checking directory permissions with MLST
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GT-11: globus-url-copy -rst segfault if the network is not working
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GT-12: GUC exits with zero when it hits a stall-timeout
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GT-273: can discover user names even with restrict path
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GT-284: GridFTP pipelining and reliability issues
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GT-374: Can’t share files in a path structure with symlinks: path not allowed error
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GT-397: gridftp doesn’t error if file with unrepresentable name is used (MLSC)
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GT-413: Clarify errors whenever sharing file operations fail
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GT-414: globus-gridftp-server closing connection before returning cksm value
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GT-450: extra newline in PASV error message
Technology dependencies
GridFTP depends on the following GCT components:
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Non-WS (General) Authentication & Authorization
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C Common Libraries
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XIO
GridFTP depends on the following 3rd party software:
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OpenSSL (version is included in release)
Tested platforms
Operating System | Distribution | Version(s) | Architecture(s) |
---|---|---|---|
Linux |
CentOS |
5, 6 |
i386, x86_64 |
7 |
x86_64 |
||
Fedora |
20, 21, 22 |
i386, x86_64 |
|
Red Hat Enterprise Linux |
5, 6 |
i386, x86_64 |
|
7 |
x86_64 |
||
Scientific Linux |
5, 6 |
i386, x86_64 |
|
7 |
x86_64 |
||
SUSE Linux Enterprise Server |
11SP3 |
x86_64 |
|
Debian |
6, 7, 8 |
i386, amd64 |
|
Ubuntu |
12.04LTS, 14.04LTS, 14.10, 15.04 |
i386, amd64 |
|
Mac OS X |
10.6-10.10 |
i386, x86_64 |
|
Solaris |
OmniOS |
r151006 |
x86_64 |
Windows 7 |
Cygwin |
i386, x86_64 |
|
MingW64 |
i386, x86_64 |
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.
Backward compatibility summary
Protocol changes since GT 6.0
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None
API changes since GT 6.0
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None
Exception changes since GT 6.0
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Not Applicable (GridFTP is not Java-based)
Schema changes since GT 6.0
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Not Applicable (GridFTP is not SOAP-based)
Associated Standards
Associated standards for GridFTP:
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RFC 2228 gssapi security extensions for FTP RFC 2389 FEAT, OPTS, etc.
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extensions to FTP (IETF FTP Working group draft) for structured directory listings, SIZE, MDTM commands.
For More Information
See GridFTP for more information about this component.