                     Announcing CVSup 16.1h
		     ----------------------
Snap-16.1h of CVSup, the CVS-aware network file distribution
system, is now available.

What Has Changed Since the Previous Snapshot?
---------------------------------------------
  Implemented some fixes necessary to build and operate under
  glibc-2.3.2.  You will most likely need to use the new version
  1.1 of Ezm3 to build CVSup on platforms using glibc-2.3.2.

Where to Get CVSup
------------------
CVSup is free software.  It is available from:

  ftp://ftp.FreeBSD.org/pub/FreeBSD/development/CVSup/

and from the many FreeBSD FTP mirrors.

On the FTP sites, the source distribution can be found in
"snapshots/cvsup-snap-16.1h.tar.gz".

An updated port will appear soon in the "net" category of the FreeBSD
ports and packages collection:

  http://www.freebsd.org/ports/

What Is CVSup?
--------------
CVSup is a software package for distributing and updating collections
of files across a network.  It can efficiently and accurately
mirror all types of Unix files, including sources, binaries, hard
links, symbolic links, and even device nodes.  CVSup's streaming
communication protocol and multithreaded architecture make it most
likely the fastest mirroring tool in existence today.

In addition to being a great general-purpose mirroring tool, CVSup
includes special features and optimizations specifically tailored to
CVS repositories.  By taking advantage of the special properties of
the files contained in CVS repositories, CVSup is able to perform
updates much faster than traditional systems.  CVSup parses and
understands the RCS files making up a CVS repository.  When updates
occur, CVSup extracts new deltas directly from the RCS files on the
server and edits them into the client's RCS files.  Likewise, CVSup
notes the addition of new symbolic tags to the files on the server and
sends only the new tags to the client.

CVSup is able to merge new deltas and tags from the server with deltas
and tags added locally on the client machine.  This makes it possible
for the client to check local modifications into his repository
without their being obliterated by subsequent updates from the server.

In addition to distributing the RCS files themselves, CVSup is able to
distribute specific checked-out versions.  The client can specify a
symbolic tag, a date, or both and CVSup will extract the appropriate
versions from the server's CVS repository.  Checked-out versions do
not need to be stored on the server, since CVSup can extract any
version directly from the CVS repository.  If the client has an
existing checked-out tree, CVSup will apply the appropriate edits to
update the tree or transform it into the requested version.  Only the
differences between the existing version and the desired version are
sent across the network.

To update non-RCS files, CVSup uses the highly efficient rsync
algorithm, developed by Andrew Tridgell and Paul Mackerras.

CVSup uses lightweight processes (threads) to implement a streaming
protocol across the network.  This completely eliminates the delays
associated with the lock-step, request-reply form of communication
used by many existing protocols, such as sup and NNTP.  Information
is transferred at the full available speed of the network in both
directions at once.  Network latency and server response delays
are rendered practically irrelevant.

CVSup uses the "zlib" compression package to optionally compress all
communications.  This provides an additional 65-75% compression, on
top of the diff-based compression already built into CVSup.

For efficiency, all processing is built into the CVSup package
itself.  Neither the client nor the server execute any other
programs.

For further information about how CVSup works, see the (somewhat out
of date) "Blurb" document in the CVSup distribution.

Using CVSup to Maintain FreeBSD Sources
---------------------------------------
CVSup servers for the FreeBSD sources are currently running at about
85 mirror sites around the world.  For an up-to-date list of them,
see:

  http://www.freebsd.org/handbook/mirrors-cvsup.html

Using CVSup, you can easily receive or update any of the standard
FreeBSD source releases, namely, "cvs", "current", and "stable".
The manual page for cvsup(1) describes how to do that.  For more detailed
instructions, see the section on CVSup in the FreeBSD Handbook:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/cvsup.html

Installation
------------
See the file "Install" in the source distribution for installation
instructions.

Status of this Release
----------------------
CVSup was first released publicly in August of 1996.  Since then
it has seen heavy use, and it has been quite stable.  Like all
software, though, it is not perfect.  Please be prepared to find
bugs -- without a doubt, there are some.

Problems?
---------
Please report bugs to <cvsup-bugs@polstra.com>.

For More Information
--------------------
http://www.cvsup.org/


CVSup is a registered trademark of John D. Polstra.
John Polstra, <jdp@polstra.com>

Copyright 1996-2003 John D. Polstra
$Id: Announce,v 1.55 2003/04/12 17:52:14 jdp Exp $
