Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.mel.connect.com.au!news.mira.net.au!news.vbc.net!samba.rahul.net!rahul.net!a2i!news.PBI.net!news.mathworks.com!newsfeed.internetmci.com!swrinde!news.uh.edu!bonkers!not-for-mail
From: John Polstra <jdp@polstra.com>
Newsgroups: comp.unix.bsd.freebsd.announce
Subject: CVSup release 13.3 is now available
Date: 23 Aug 1996 17:01:10 -0500
Organization: FreeBSD Project
Lines: 198
Sender: daemon@taronga.com
Approved: peter@taronga.com
Message-ID: <4vl9n6$scg@bonkers.taronga.com>
NNTP-Posting-Host: localhost.taronga.com
Announcing CVSup 13.3
---------------------
Release 13.3 of CVSup, the CVS-aware network distribution system, is now
available.
Where to Get CVSup
------------------
CVSup is free software. It is available from the following FTP sites:
ftp://freefall.freebsd.org/pub/CVSup/
ftp://ftp.freebsd.org/pub/FreeBSD/incoming/
ftp://ftp.polstra.com/pub/FreeBSD/CVSup/ (slow; avoid if possible)
Full sources as well as FreeBSD binaries are available:
cvsup-bin-13.3.tar.gz FreeBSD binaries for the client
cvsupd-bin-13.3.tar.gz FreeBSD binaries for the server
cvsup-13.3.tar.gz Sources **
The MD5 signatures for these files are:
MD5 (cvsup-bin-13.3.tar.gz) = 63e7a4cdf60973a8660486ab3d67680c
MD5 (cvsupd-bin-13.3.tar.gz) = 221c98c87841fbaf1dc3a6740d0571c4
MD5 (cvsup-13.3.tar.gz) = c4c4ac290e53206a15b3645f1e173284
** If you wish to build CVSup from the sources, be sure to read the
discussion further on in this announcement.
What Has Changed Since the Previous Release?
--------------------------------------------
Implement a passive mode for establishing the data connection,
to help people who live behind firewalls. Passive mode is similar
to ftp's passive mode: all TCP connections are initiated from
the client. See the "-P -" option in cvsup(1).
Make the system much more resiliant in the face of errors in the
server's CVS repository, such as unreadable files and garbled
RCS files. Almost all such situations now lead to simple warnings,
rather than fatal errors.
Make it a warning rather than a fatal error when the client
specifies an invalid collection.
Fix the broken "refuse" file handling.
Make the server refuse to run as root, for security reasons.
Fix a bug that could cause a fatal error to occur in certain
situations involving local check-ins to RCS files in the CVS
repository.
Fix a server bug encountered during SOCKS testing. Note: This
release of CVSup still does not work with SOCKS.
Enable TCP keepalives on the server.
What Is CVSup?
--------------
CVSup is a software package for distributing and updating collections
of files across a network. CVSup is specifically tailored to
distributing 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. It is
especially valuable for people with slow Internet connections.
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.
Note: Although this feature is fully implemented in CVSup, it will
probably not be practical to use it until some small changes have been
made to CVS.
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.
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 executes any other
programs.
For further information about how CVSup works, see the "Blurb" document
in the CVSup distribution.
Using CVSup to Maintain FreeBSD Sources
---------------------------------------
CVSup servers are currently running at the following FreeBSD mirror
sites:
cvsup.freebsd.org
cvsup2.freebsd.org
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.
If all goes well, additional servers will come on-line soon.
Building CVSup from the Sources
-------------------------------
CVSup is written in Modula-3, a modern, compiled, object-oriented
language. Modula-3 integrates threads, exceptions, and garbage
collection, providing an ideal vehicle for this sort of application.
Without Modula-3, CVSup would almost certainly not exist today.
If you wish to build CVSup from the sources, you will first need
to install the free Modula-3 compiler and runtime libraries from
DEC SRC. A port is available in the FreeBSD ports collection, in
"lang/modula-3". The corresponding package is, of course, available
in the packages collection.
You will also need version 1.0.4 or later of the "zlib" library.
In recent versions of FreeBSD-2.2-current, this library has been
incorporated into the system sources, in "src/sys/lib/libz". Prior
to that, a FreeBSD port was available in "devel/libz" of the FreeBSD
ports collection. For other sources of this library, see the "Install"
file. Do not try to use versions earlier than 1.0.4.
There is no conceptual problem with installing the Modula-3
distribution and building CVSup from source. However, it is rather
inconvenient at present because the DEC SRC distribution contains
several separate, large software projects that were developed using
it. This makes the installation very large -- about 60 MB. Worse
yet, one of the extraneous components requires a tremendous amount
of swap space to build. You'll need at least 64 MB of swap and,
even then, you'd better kill your X server during the build.
Again, the problem lies not with Modula-3 itself but rather with
the extra software that is included with it. I am working on
splitting the FreeBSD Modula-3 port into several smaller ports in
order to make it more convenient to install and use.
Meanwhile, for convenience, I am providing binary releases for
CVSup.
Portability Issues
------------------
I intend for CVSup to be portable to most POSIX systems. The
present release has only been tested under FreeBSD versions 2.1
and later. Primarily because of packaging problems, this release
of CVSup probably won't build out-of-the-box on other systems.
Among other things, it relies on Poul-Henning Kamp's "libmd"
encapsulation of the MD5 subroutines. The library itself appears
to be quite portable, but its Makefiles are BSD-specific. There
are probably some other FreeBSD-specific things in CVSup that have
not been found yet.
Also, CVSup relies on a couple of patches and enhancements to the
Modula-3 system. These changes have been submitted to DEC SRC and
accepted by them, but they have not yet appeared in an official release
from SRC. The FreeBSD port of Modula-3 includes these enhancements.
Anybody who succeeds in porting CVSup to other systems is encouraged
to send his changes to <cvsup-bugs@polstra.com>. As long as the
changes are reasonably palatable, they will be incorporated into
future CVSup releases.
CVSup uses several POSIX-specific functions which may make it more
of an effort to port the package to non-POSIX systems such as Win32.
These functions include mmap, fork, syslog, stat, and chmod, among
others.
Status of this Release
----------------------
CVSup has been in alpha testing since mid-May. This should be
considered a beta release. Please be prepared to find bugs --
without a doubt, there are some. Please report bugs to
<cvsup-bugs@polstra.com>.
--
John Polstra jdp@polstra.com
John D. Polstra & Co., Inc. Seattle, Washington USA
"Self-knowledge is always bad news." -- John Barth