install.ms.2

早期freebsd实现

\fIinnd\fP will close and re-assign two descriptors every 10 or so articles.
.PP
A better alternative is to use funnels and an exploder.
Funnels, specified in the \fInewsfeeds\fP file, let multiple sites send
their output down a single stream.
The advantage of funnels is that this stream can be a channel; the primary
disadvantage is that the funnel specifies what data is to be written,
not the individual sites.
(Since most feeds will want either ``Wn'' or ``Wnm'' entries, this is
usually not a problem.)
.PP
In order for the funnel output to be useful, it usually must be split into
individual, per-site, files.
Programs that do this type of splitting are called ``exploders.''
INN provides two exploders, \fIfilechan\fP and \fIbuffchan\fP.
.PP
\fIFilechan\fP is the simplest, and most inefficient, exploder.
It does not keep any files open and is very system-call intensive.
It can be used to provide behavior (and performance!) that is similar to
B2.11 \fIinews\fP.
It can, however, be used as the funnel for an unlimited number of sites.
.PP
\fIBuffchan\fP keeps all its output files open all the time.
It should not be used for more sites then a single process can have open.
\fIBuffchan\fP also has flags to automatically flush its files, as well
as close and re-open them, every specified number of articles.
(The re-open capability is useful for things like \fInntplink\fP in its
\&``watch the batchfile'' mode.)
Using \fIbuffchan\fP with the ``\-l1\ \-c50'' flags will give behavior
that is similar to the C News \fIrelaynews\fP.
.PP
\fIBuffchan\fP can be run as a full exploder (``Tx'') in the
\fInewsfeeds\fP file.
This means that you can use \fIctlinnd\fP to send a command line down
\fIbuffchan\fP's input stream.
(\fIInnd\fP will also send a command whenever newsgroups are modified.)
The only useful message is ``flush'' which will close, and re-open, the
specified site files.
You should also note that the flow is one-way; full exploders cannot send
any acknowledgement back.
.NH 1
Master/slave replication
.PP
INN supports a simple model of replicated news databases:
a single master host pushes out updates to its slaves.
The master is the only host that receives articles \(em this includes
both outside newsfeeds and articles written by local users.
The slaves only receive articles from the master.
.PP
No special work is required to set up a master host.
.PP
A slave is set up by starting \fIinnd\fP with the ``\-S'' flag to specify
the name or IP address of the master host.
This should be done by modifying the ``FLAG'' variable in your
\fI_PATH_NEWSBOOT\fP script.
If \fIinnd\fP is started with the ``\-S'' flag it will pass this flag on
to \fInnrpd\fP.
This means that when anyone connects to the slave and does a ``POST'' command,
\fInnrpd\fP will connect to the master and offer the article.
.PP
Since the \fInnrpd\fP on the slave host will usually add its name to
the Path header, you should add ``Ap'' to the \fIflags\fP field of
the slave's entry on the master.
.PP
Once the slave has been set up it is necessary to have the master feed it.
This is done by using an extension to the NNTP protocol.
This extension, the ``XREPLIC'' command, is is documented in \fIinnd.8\fP.
In order to do this you will have to set up a \fInewsfeeds\fP entry for
the slave.
This should be a standard entry except that you will need to have both
the filename and the replication information written int the batchfile.
To do this, put ``WnR'' in the \fIflags\fP field of the entry.
.PP
When you want to actually send the articles to the slave site you will
have to specify the ``\-S'' flag in your \fIinnxmit\fP command.
Current versions of \fInntplink\fP use the ``\-x'' flag.
.PP
When running as a slave, \fIinnd\fP is very paranoid about staying synchronized
with its master.
Most noticeably, you should make sure that all newgroup and rmgroup control
messages are handled identically on both systems.
.\"
.bp
.SH
Appendix IV:  First-time Usenet or NNTP Installation
.PP
Since the needs and administration of systems varies so much, I can
only give some general guidelines and advice in this section.
Like 
.UX
system administration in general, it is unfortunately still true that
most of the job will be learned ``in the heat of the moment.''
Once you have INN set up, however, it should not require much attention.
For general problems, try posting to ``news.sysadmin'';
use ``news.software.nntp'' and ``news.software.b'' for installation problems.
.PP
Once all the software has been compiled and installed, you must now
get a newsfeed.
This involves having one (or more) sites pass along to you all the
articles that they have received.
Getting articles is a passive action, because it is generally more
efficient that way.
(The \fInntpget\fP program is primarily a debugging aide and utility
program.
It is not the recommended way to get a newsfeed, and most sites will
prefer you not to use it for that.)
.PP
If you already have Usenet access, you could post a note to ``news.admin''
asking for a feed.
Make sure to say that you are looking for an NNTP connection!
If you are a member of an NSFNet regional network, or subscribe to
a commercial IP network, ask your contact there at the network center.
If they do not provide feeds directly, they can probably help you find
one.
You also might try writing to the <[e-mail]>
mailing list.
This will reach the news administrators of many NNTP sites on the Internet.
(If you want to join the list, remember to send it to
nntp-managers-request, \fBnot\fP nntp-managers!)
.PP
Once have a site willing to give you a feed, you need to get the
list of groups that they will give you.
You also need to create those groups on your machine.
The easiest way to do this is usually to ask them for a copy of
their active file, and for you to add the entries of the groups that
you're interested in.
.PP
Once the groups are set up, your newsfeed will periodically connect to
your NNTP server and offer it any new articles that have arrived since the
last connection.
\fIInnd\fP will accept the connection, receive the articles, and
queue them up for any sites that you feed.
.PP
The next step is to set it up so that your articles are sent back to
your newsfeed.
To do this, create a \fInewsfeeds\fP entry, using the same name that shows
up in the Path header that you see.
(If you use a different name, then use the ``excludes'' sub-field to avoid
offering back everything they offer you.)
This is usually done by giving them all non-local articles as a file
feed.
For example, ``Foo, Incorporated'' does not give any foo.* articles to
anyone else.
.PP
When someone at your site writes an article, \fIinnd\fP will record the
filename in the batch file for your upstream site.
Either \fIsend-nntp\fP or \fInntpsend\fP will flush and lock the batchfile,
and then call \fIinnxmit\fP to connect to the remote site and send these
queued articles out.
You should edit the script to list the sites you want, and arrange for
\fIcron\fP to run this script on a regular basis.
You can run it as often as you like, but 10 minutes is a common interval.
.PP
If you want to feed any sites via UUCP, then you will have to set
up file feed entries for them in the \fInewsfeeds\fP file, and arrange
to have \fIcron\fP run the \fIsend-uucp\fP script as desired.
(UUCP batches are typically only done every few hours.)
.PP
Once you have news flowing in and out of the system, you will have
to expire it or your disks will fill up.
The \fInews.daily\fP script should be run by \fIcron\fP in the middle
of the night.
It will summarize that day's log files, and then call \fIexpire\fP to
purge old news.
You might also want to have \fIcron\fP run \fIrnews\fP hourly to pick
up any stalled batches.
Finally, if your feeds change IP address, you might want a daily job
that does ``ctlinnd reload hosts.nntp "flush cache"''.
This is because \fIinnd\fP does not currently time-out DNS entries.
.PP
You will generally want to set up the \fIcron\fP jobs
so that they are run as the news administrator, and not as root.
A good version of \fIcron\fP that makes it easy to do this can be found
on gatekeeper.dec.com in pub/misc/vixie/cron.tar.Z.
.PP
You will also need to get one or more programs to read news.
There are several freely-available programs around.
\fIRn\fP is popular, and is probably the best place to start.
The official distribution is available for anonymous FTP at tmc.edu
in the \fIrn\fP directory.
.PP
Welcome to Usenet, and have fun!
.\"
.bp
.SH
Appendix V:  News overview database
.PP
There are now many newsreaders available that are able to do ``threading.''
This is the ability to track a discussion within a newsgroup by using
the References header (or other data), regardless of changes in headers
like the Subject line.
Examples of these readers include \fInn\fP, \fItrn\fP, and \fIgnus\fP,
and more are becoming available.
Until recently, a major problem with these readers is that they all
required a specialized external database that contained the threading
data.
.PP
In late 1992, Geoff Collyer <[e-mail]> released the \fInov\fP,
or ``news overview,'' package.
This included database tools and, and client access routines,
that let the current threaded newsreaders use a common, textual,
database.
An overview database typically adds adds about 7-9% to your storage
requirements.
By default, the overview files are stored in the spool directory;
you can change this to use an alternate tree that mirrors the spool
hierarchy by changing the \fI_PATH_OVERVIEWDIR\fP parameter.
.PP
INN includes full support for creating and expiring news overview databases.
To do this, add an entry like the following to your \fInewsfeeds\fP file:
.DS
overview:*:Tc,WO:/path/to/bin/overchan
.DE
(Make sure to replace \fI/path/to/bin\fP with the value of your
\fI_PATH_NEWSBIN\fP parameter.)
Then reload the \fInewsfeeds\fP file or restart your server.
To create the initial database, run the following command after you have
started \fIoverchan\fP:
.DS
expireover -a -s
.DE
You will also need to expire the overview data.
The easiest way to do this is to add the ``expireover'' keyword to
the \fIcron\fP job that runs \fInews.daily\fP.
.PP
The \fInnrpd\fP server includes two command extensions to access the database;
they are documented in the ``protocol extensions'' part of \fIdoc/nnrpd.8\fP.
INN does not include any client code or modifications to any newsreaders
to use the overview data.
Most maintainers have agreed to support the overview database, including
the INN extensions for remote access.
You can find prototype versions of many readers (work done by Geoff) on
world.std.com in the directory src/news; look for files named
\fIreader\fP.dist.tar.Z.
.\"
.bp
.SH
Appendix VI:  Limited MIME Support
.PP
This version of INN includes limited support for MIME, the Multipurpose
Internet Mail Extensions, described in RFC 1341.
The support is the ability to do limited transport of arbitrary
MIME messages, and \fInnrpd\fP can add MIME headers to all local postings
that do not have them.
.PP
In addition, there are patches available for \fInntplink\fP that
allow it to do MIME transport.
The patches are not (yet) part of the official release; if you need them,
contact Christophe Wolfhugel <[e-mail]>; he did
most of the INN work, too.
.PP
You should be very careful if you have \fInnrpd\fP add MIME headers.
To do this, edit \fIinn.conf\fP as indicated in \fIdoc/inn.conf.5\fP.
Once this is done, \fBall\fP articles posted will get MIME headers added.
Existing MIME headers will not be modified, but missing ones will be added.
The default values to add to \fIinn.conf\fP are these:
.DS
mime-version: 1.0
mime-contenttype text/plain; charset=us-ascii
mime-encoding: 7bit
.DE
An internationalized site might want to use these values:
.DS
mime-version: 1.0
mime-contentType: text/plain; charset=iso-8859-1
mime-encoding: 8bit
.DE
It is possible to use these values because INN provides a clean eight-bit
data path.
Unless you make special arrangements with your peers, however, you
must transmit seven-bit data.
Doing this will require special transmit agents.
Note that \fInnrpd\fP is not a Mime-compatible reader.
You must have software to extract the data and present it appropriately.
.PP
If you configure your site to use seven-bit data, then you must also
make sure that none of your software creates eight-bit articles.
\fINnrpd\fP does not verify this.
If you configure your site to use eight-bit data, then ASCII works fine,
but remember that in quoted-printable long lines are cut and
that the equal sign (``='') is quoted; this is really bad for source code
postings, among others.
.PP
The character set can also cause problems.
If you use ``iso-8859-1'' you must make sure that your posting software
uses this character set (e.g., not CP-437 under MS-DOS) because \fInnrpd\fP
does not do any conversion.
.PP
In general, be very cautious.
.PP
MIME articles can only be sent using \fIinnxmit\fP; work on \fIbatcher\fP
is in progress.
Unless the ``\-M'' flag is used, no MIME conversions are done.
If the flag is used, the following happens:
Articles with a Content-Transfer-Encoding header of ``8bit'' or ``binary''
are forwaded in ``quoted-printable'' format (the ``base64'' format will
be available soon).
All other articles -- in particular, those without MIME headers, those of
type ``message'' or ``multipart,'' those with Content-Transfer-Encoding
header of ``7bit'' -- are forwarded without any change.