What is AFD?

The Automatic File Distributor provides a framework for very flexible, non-stop, log and debug-able delivery of an arbitrary amount of files to multiple recipients as expressed in URLs (mailto://user@domain, ftp://user:password@host, etc). AFD stands for Automatic File Distributor.

The most common technique used to distribute data is for each individual to fetch the data from one common place. This place can be a database, FTP-server or even the WWW (World Wide Web). However, this is not always the most user or customer friendly way for a company or organization to distribute its products. For this reason AFD (Automatic File Distributor) was developed, to provide a better service to users or customers in transporting the required data directly to the location where it is required.

When distributing files to a remote host it does so via the FTP, FTPS, SFTP or SMTP protocol. Local distribution is done by simply copying or if possible move files from one directory to another. To distribute files, the AFD has one (or more) central configuration file ( DIR_CONFIG), where the system administrator can specify which files are to be distributed and where they are to be sent.

Here follows a list of features of the AFD:

The AFD can send/retrieve any type of file, regardless of contents and the name of the file.
It supports the following protocols: FTP, SMTP, HTTP, SFTP, SCP and WMO socket protocol. TLS/SSL connections for FTP and HTTP are also possible. AWS4 S3 storage via HTTPS is supported.
Only the files are being distributed, no other additional information is send with the file.
The AFD has a very sophisticated and compact X11 interface to monitor and control the distribution of files (afd_ctrl). It has the ability to do extensive logging of all activities, even down to tracing each individual FTP/FTPS/SMTP/SFTP/SCP/HTTP command.
It is possible to run AFD without the X11 interface, command line tools allow you to do everything without the GUI.
Files can be send to places where no AFD is installed.
There can be more than one process distributing files to a single host. This has the advantage that when a large file is currently being distributed, other files don't have to wait until the large file is done.
Where net capacity is limited, it is possible to distribute files with priority and by limiting the bandwidth.
If the transfer gets interrupted, AFD can append files. So data that has already been transmitted will not be send again.
It is possible to setup a whole network of AFD's that can be monitored and controlled through a single interface (mon_ctrl).

The AFD requires X11R5 and Motif 1.2.x (or higher) for the GUI. Currently it has been ported to the following systems:

Linux (x86, x86_64) 1.3.x - 6.x
Solaris 2.x
HP-UX 10.x - 11.x
IRIX 5.3 6.x
AIX 4.3 - 5.3
MacOS 10.3
FTX 3.0.x 3.2.x
SCO OpenServer Release 5

I expected it to run on any kind of unix system, but due to the fact that I do not have access to all kinds of unixes, unable to test this other than the above mentioned systems.

The AFD is now for nearly thirty years in operational use at the DWD at over 240 installations distributing 100 million files (160 Tbytes) daily.

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