Known Problems

If you use NIS (formerly Yellow Pages) on SunOS, you will need to add a ``domainname'' entry to your inn.conf file if your hosts do not contain fully-qualified domain names. The most common symptom of this is that inews will fail because it cannot generate a Message-ID. Another problem with NIS is that reverse name lookups do not return the fully-qualified domain name. If you know that none of your local clients have a period in their name, you can use a pattern like ``*[^.]*'' in your nnrp.access file.

SunOS4.1.1 has a bug where write(2) can return EINTR. The most common symptom is the following fatal error message from innd: Can't sync history, interrupted system call This is Sun bug 1052649. It is fixed in patch 100293-01. According to the release manual, it is also fixed in all releases of SunOS since 4.1.2.

If you have NOFILE_LIMIT set you should know that the standard I/O library in SunOS4.x has trouble with more than 127 descriptors. The most common symptom is the following fatal error message from innd: can't fopen /usr/local/news/history, invalid argument This occurs after doing a ctlinnd ``reload'' command. For a work-around, reboot your server instead of trying to ``reload.'' Another symptom is that innd will exit if you do a ctlinnd ``flush'' command while the server is paused or throttled. This is Sun bug 1045141. Sun does not plan to fix it for any 4.x release.

One site has reported the same error message happens after doing a sequence of ``throttle'' and ``go'' commands. It does not appear to be related to the bug mentioned above, although the symptom is the same. If you replace the body of INN's xfopena routine with the following, it will work: return fopen(p, "a+"); This is in the file lib/xfopena.c.

If you use Sun's unbundled compiler, acc, you must make sure to use the unbundled assembler, too. You might also get lots of ``left operand must be modifiable lvalue'' errors. Setting USE_CHAR_CONST to ``DONT'' will help.

There have been reports that the VAX Ultrix 4.2 malloc doesn't work well with innd, causing it to slowly fill up all swap space. I believe that all of the memory leaks in innd have been fixed, but you might want to look at using a different malloc package. The Kingsley/Perl malloc package is provided in the lib directory. Add ``malloc.c'' and ``malloc.o'' to the MISSING_SRC and MISSING_OBJ lines in config.data and rebuild.

I have been told that on SunSoft Interactive UNIX System V Release 3.2 Version 3.0 systems <errno.h> has been broken up into separate files. The easiest way to work around this problem is to add ``#include <net/errno.h>'' to include/clibrary.h.

If you use 386BSD (the Jolitz port, not the BSDI product) you will have to set ACT_STYLE to ``READ''. If you do not do this then the active file will not get updated. Another work-around is to set MMAP_SYNC parameter to ``DO.''

The default configuration of some Sequent kernels does not provide enough descriptors for innd to run. You might have to rebuild your kernel with the ``MAXNOFILE=128'' and ``NOFILEEXT=64'' options. You will also have to had a ``setdtablesize(nnn)'' call in the main routine of innd, and a ``setdtablesize(0)'' call in the Spawn routine.

I have been told that some older versions of the SCO opendir routine have file descriptor leaks. The most noticeable symptom is probably that innd will die while trying to renumber the active file. You might want to use a freely-redistributable ``dirent'' package such as one distributed by the Free Software Foundation. You should also make sure to set CLX_STYLE to ``FCNTL.'' Finally, you might also want to edit innd/innd.c where it calculates the ``MaxOutgoing'' parmater and increase the fudge number to four.

On some SVR4 systems, attempting to set the socket buffer size is either not supported or, even worse, might result in innd's data size growing. The most noticeable symptom is ``cant setsockopt(SNDBUF)'' messages in your syslog output. To fix this, you should make sure to set SET_SOCKOPT to ``DONT.''

I have heard that Sony SVR4 systems have lots of problems. You must set HAVE_UNIX_DOMAIN to ``DONT''; sockets in general seem to have problems, including kernel crashes and a blocked innd.

If you use the GNU sed in the _PATH_SED configuration parameter, make sure you get version 1.13; earlier versions have a bug that breaks the parsecontrol scripts. The most noticeable symptom is that all ``newgroup'' control messages result in mail saying that they are unparseable.

Some versions of the shell in HP-UX do not properly parse a quoted ``['' when it is in a pattern for a case statement. The most noticeable symptom is that news.daily does not properly expire articles if innwatch has throttled the server. Contact HP and get a fix for SR # 5003-009811.

On some versions of AIX on the RS/6000, using memory-mapping can eat up all the page space or crash the machine. This will be noticeable if you have ACT_STYLE set to ``MMAP'' and/or have ``-DMMAP'' in DBZCFLAGS. Ask your IBM representative for the ``U413090'' PTF and prerequisites to apply it; it is believed that this will fix it.

On some systems processes spawned by innd never exit. The most likely cause is that CLX_STYLE should be set to ``FCNTL.''

Appendix I: Differences from other News software

Administrators will find that INN is fairly incompatible with B and C News. This section tries to mention the most important places where INN differs from the other news systems. If you have not maintained B or C News, you should probably skip this section.

Users will generally only notice is that INN is faster; it should be 100% compatible with the other systems at the user level. If you had particular problems that aren't mentioned here, please let me know. Note, however, that this is not a tutorial on how to set up a new INN system, or convert older software to it; no such document exists except appendix II ``Converting from other News software''. Configuration Files

Below is a list of the data files used by B and C News, and the reference NNTP implementation, along with a short summary of how they map into INN configuration files. The syntax is always different: INN files are almost always a set of colon-separated fields where lines beginning with a poundsign are ignored.

explist
    This is replaced by the similar expire.ctl file. Archiving is done by a separate program.

mailpaths
    This is replaced by the moderators file. The ``default'' entry in mailpaths is replaced by either a full wildcard (``*'') entry in the moderators file, or by a ``moderatormailer'' entry in the inn.conf file.

nntp.access
    This is replaced by the hosts.nntp (for NNTP peers) and nnrp.access (for newsreading) files.

nntp.sys
    This is a password file used if NNTP is compiled with the ``AUTH'' option. It is replaced by the passwd.nntp file. Note that inews and rnews will also try to read passwd.nntp. Therefore, you will probably want to have one-line versions of it for your on-campus clients.

organization
    This is replaced by the ``organization'' entry in the inn.conf file.

rn/server
    This is replaced by the ``server'' entry in the inn.conf file.

whoami
    This is replaced by the ``pathhost'' and ``fromhost'' entries in the inn.conf file. Newsgroups, Active, Sys, and Newsfeeds

The biggest difference is how the newsfeeds file compares with the sys file. Newsgroup patterns like ``all.all.ctl'' are completely gone. All newsgroup patterns are shell-style wildcards, matched against the active file.

The active file is taken to be the definitive list of newsgroups that you want to receive. With B and C news, an article must match the subscription list of the local site as specified in the sys file. If it matches, each newsgroup is then looked up in the active file. If none of the newsgroups are found, then the article is filed into the newsgroup named ``junk''.

INN's behavior is much simpler. If a newsgroup does not appear in the active file, it is ignored. If none of the groups are mentioned, then the article is rejected: nothing is written to disk. This is a deliberate design decision: if you do not want a particular newsgroup to take up your disk space, remove it from the active file; if your neighbors have not gotten around to updating your newsfeed, then the only thing that will happen is that some network bandwidth will have been wasted when they send you the article.

You can change INN's behavior so that it resembles the other systems. To do this, compile with WANT_TRASH set to ``DO.'' Note that this will accept everything. Because there is no subscription list, you cannot say ``give me all of the foo hierarchy (filed into junk), but not the alt hierarchy.'' You must list the group in the active file.

INN strictly believes in distributions. If the site named ME has any distributions, then incoming articles must either have no Distribution header, or the header must match the distribution list. If you want to blindly accept all distributions, make sure you do not have a ``/distrib,...'' section in your ME entry. Distributions are fixed strings — there are no patterns or special wildcards like ``all.''

For more details on these items, see doc/newsfeeds.5. Control Messages

Like C News, INN implements all control messages other than cancel as shell scripts. The number and type of parameters is different from that of C News. All control messages consult the file control.ctl before acting on the message. If the sender's address matches with the list of authorized addresses (e.g., ``group-admin@isc.org'', ``*'', etc.), the control message is either acted upon, mailed to the news administrator, logged, or dropped. For example, messages from ``group-admin@isc.org'' are honored.

The ``control'', ``junk'', and ``to'' newsgroups can be explicitly sent or not sent. See doc/newsfeeds.5 and doc/innd.8.

The ctlinnd program is what really directs the server to create or remove newsgroups. This results in a semi-recursive process: the control message arrives, and a script is invoked to process the message. If approved, the script invokes ctlinnd to send a message back to the server telling it to create or remove the group. Locking

A running news system has many open files. These files can be divided into two groups. The first group includes the history database and active file. The second group includes the logfiles and batch files used to send articles to your feeds.

B news uses an internal protocol for the first group. For the second group, since inews does ``atomic appends,'' no locking is necessary. C news uses the locknews and newslock scripts for the first group, and provides no fine-grain mechanism for the second group.

With INN, the server is running all the time and all locking is done under the direction of ctlinnd. The first group is generally handled by using the ``throttle,'' ``pause,'' and ``go'' commands (sometimes ``reload'' will be necessary). The second group is handled by the ``flushlogs'' and ``flush'' commands. See the doc/ctlinnd.8 manpage; examples of their use can be found in various scripts in the samples directory.

Appendix II: Converting from other News software

INN is a complete news transport and expiration system. Since some people will be installing INN from scratch on top of an older news system, this section should help you determine what you can ``throw out'' from your earlier news setups. It is also compatible with much of the existing news software, so you can create a mixed environment if you want to, and if you are careful. C News Expire

The expire program that is distributed with INN does not do any archiving. Since the history databases currently have the same format, it is possible to use the C News expire if you want to. (The INN history database may change, however, so you should only do this if you really have to — you really should use INN's expire.) There are three ways to do this.

The first way is to change your doexpire script so that it calls ctlinnd to ``throttle'' innd just before expire runs. It should then issue a ctlinnd ``go'' command after expire is done. The drawback to this method is that no incoming news is accepted until all expiration is finished.

The second way is to compile lib/lock.c and add it to your C News library libcnews.a, replacing the provided lock functions. You should then remove expire and relink it. This method has not been tested very thoroughly, but it is rather simple.

The third way is to teach the C News expire to talk to innd and tell it to cancel articles that it would remove. To do this, apply the patch file expire/expire.pch to your C News expire.c sources. You will also have to add lib/inndcomm.o to libcnews.a and then rebuild expire. Standard NNTP daemon

You can use the ``standard'' nntpd server. You should only have to do this if you have hosts that feed you news, and where the users on that machine also want to read news on your machine.

Make sure that you configure nntpd so that it is using DBZ, and have it feed each individual article to inews; don't use the ``batched input'' option. It should also be set up so that it acts as if it is running under inetd. You should also make sure that inetd does nothing with the NNTP port, number 119. NNTP-based newsreaders

If you already have your NNTP-using newsreaders installed and running, you do not have to do anything. This includes xvnews, xrn, rrn and so on. INN implements the standard NNTP protocol, with some extensions. INN does not provide the extensions used by trn, tin or other newsreaders. (INN will not implement all the different indexing systems because the right solution is to have a generic interface that all readers can use.)

For administrative convenience, however, you might wish to have all your newsreaders use the INN library and configuration files to talk to the server. The next section describes how to do that for rn. It is provided as an example, to help you convert other programs you might have. INN does not provide, nor fully support, any newsreaders. Remote rn

The ``remote'' version of rn (also called rrn) uses a set of routines in the NNTP ``clientlib'' file. INN can emulate these routines; see doc/clientlib.3. If you need to build rn for client machines that don't have the entire INN distribution available, use the MakeLib script to build a distribution directory of the necessary routines. Use this script the same way you use the MakeInews script.

Rn, rrn, and trn are constantly changing so these instructions might be out of date. The maintainers have agreed to officially support INN, however.

There are two ways to build rn so that it uses the INN library. If you don't have the NNTP distribution installed you will have to use the first way.

The first way is to apply a patch to the latest rn Configure script and then execute it and rebuild the program. To do this, type the following: cd rn_source patch <$inn/frontends/rn.pch ./Configure make At some point, Configure will ask you if you want to use the InterNetNews library; answer yes. You can then use either the full sources, or a special library that contains just the needed header and sources files. Tell Configure the appropriate pathnames, and then proceed with the rest of the rn installation.

The second way is to edit a couple of files after you have run Configure and set it up to build the remote rn. First, replace the rn file server.h with the INN file include/myserver.h. The next step is to edit the rn Makefile to remove the ``clientlib'' file from the source and object file lists. This can probably be done by commenting out the definitions of the c5 and obj5 variables. You must also edit the Makefile to add the INN library to the list of libraries that are linked in. This can probably be done by editing the line that defines the libs variable so that the full pathname to libinn.a is the first item after the equal sign. Removing the Other Stuff

The names below assume a ``standard'' news setup; things might be different on your machine. Also, many programs have alternate names and links; make sure you chase down and remove all of them.

You might find it easiest to rename your /usr/lib/news (and /usr/lib/newsbin) directories to something else and start with a clean slate, copying over the files as they are needed. Make sure that your news processing is completely stopped before you begin this process. That includes any cron jobs that may be running.

The /usr/lib/news directory can become cluttered — that's why C News split everything up into separate directories. The following files are compatible with C News and B2.11 News, and should be kept:
active    active.times
If you are running C News keep these files, otherwise delete them and use makehistory to rebuild them: history history.dir history.pag

Rn does not have to be modified so leave this directory alone (or copy it back if you moved your original): /usr/local/lib/rn If you set up rn to use the INN library, remove this file: /usr/local/lib/rn/server

The input system is completely replaced. Remove the following programs and their manpages: /bin/cunbatch /bin/inews, /usr/lib/news/inews, etc... /bin/rnews, /usr/bin/rnews, etc... /usr/lib/news/rnews.stall /etc/nntpd, /usr/etc/nntpd, etc... Also remove the following directories and everything within them: /usr/lib/news/bin/input /usr/lib/news/bin/relay /usr/lib/news/bin/ctl /usr/lib/news/bin/inject /usr/lib/news/nntp (mkgrdates, nntp_access, shlock, etc)

The transmission facility is completely replaced. You may keep your current feed subsystem if you want to, but it will require some changes to make sure that batchfiles are properly flushed; see the send-xxx scripts for examples. Remove these files and programs: /usr/lib/news/batchparms /usr/man/man8/newsbatch.8 Remove the following directory and everything within it: /usr/lib/news/bin/batch You can continue to use nntplink, newsxd, and the like, subject to the caveat just mentioned.

Article expiration and maintenance of the history and active files is completely replaced. Remove this file: /usr/lib/news/explist Remove the following directories and everything within them: /usr/lib/news/bin/expire /usr/lib/news/bin/maint If you do not remove the expire directory, you will probably have problems installing INN's expire, which is a program that often has the same name as the C News directory.

The following programs in /usr/lib/newsbin are not needed and can be deleted. Keeping them around is harmless, and if you find them useful don't delete them:
canonhdr    newshostname
ctime    newslock
dbz    queuelen
getabsdate    sizeof
getdate    spacefor
gngp Note that ctime, getabsdate, and getdate are replaced by convdate. More importantly, newslock does not lock innd; it is best to remove it.

The following files are replaced by INN configuration files. You should delete them, just to avoid confusion:
mailname    sys
mailpaths    whoami
organization If you have other software that uses them (except sys), you can keep them. The following will be rebuilt (or overwritten) by innd and scanlogs so you should remove them:
errlog    log

In addition to the manpages for the programs listed above, the following manual pages should be removed:
active.times.5    newsmail.8
expire.8    newsmaint.8
mkgrdates.8c    nntpd.8c
news.5    nntpxmit.1
newsaux.8

Any other files and directories can probably also be discarded.

Appendix III: Setting up different feeds

This section gives some notes and advice on how to set up different types of outgoing news feeds. It duplicates and expands upon the information in the manual pages. Ihave/sendme feed

For a standard UUCP newsfeed, a site batches up all the articles it receives and sends them to the downstream site, which unpacks the batch and processes each article. If the downstream site has multiple feeds, however, it might want to ``filter'' the articles that get sent. This is done by having the feeding site send a list of Message-ID's as an ``ihave'' control message. The receiving site examines the list to see which articles it does not currently have, and sends it back to the upstream site as a ``sendme'' message. The original site receives this message and prepares a batch in the standard way.

Note that this has nothing to do with NNTP. It is a specialized type of batched feed that is not used very often. To do ihave/sendme with a site named remote, the local site must either have a ``to.remote'' newsgroup or be compiled with MERGE_TO_GROUPS set to ``DO.''

Accepting an ihave/sendme feed is easy. Suppose an ``ihave'' message is received from a site named remote. When innd processes the message it will invoke the appropriate control script, /usr/local/news/bin/control/ihave. The script will filter the body using grephistory, creating a list of Message-ID's not found in the history database. It uses this output to create a ``sendme'' control article which is posted to the ``to.remote'' newsgroup using inews. This article will then be queued and sent to remote in the normal way. The remote site will then send the desired articles back.

Providing an ihave/sendme feed is a bit more complicated. First, you must create two entries in your newsfeeds file. The first should be named remote.ihave. Make this a ``Tf,Wm'' feed that contains the remote's subscription list. This entry results in a a file that accumulates the Message-ID's of all articles that remote might want. The other entry should be named remote. This should be a ``Tf,Wn'' feed that only subscribes to the ``to.remote'' newsgroup. (Actually, if you feed some groups as a standard feed, you can put them on the remote entry, rather then the remote.ihave entry.)

The next step is to have the ``ihave'' control messages sent out. To do this, review the send-ihave script and make sure it is invoked as needed (usually out of cron). It splits the batchfile from the remote.ihave newsfeeds entry and posts ``ihave'' control messages into the ``to.remote'' newsgroup. These messages will get queued for the remote entry.

The next step is to send out any articles queued for the remote entry. Treat this as a standard UUCP feed, invoking send-uucp or sendbatch as appropriate, typically a few minutes after send-ihave runs.

When the remote site receives the ``ihave'' message it will filter it and send back a ``sendme'' message whose body is the list of desired Message-ID's. When innd processes this message it will invoke the appropriate control script, /usr/local/news/bin/control/sendme. This script will call grephistory to turn the list into a list of files appended to the batchfile for remote. Examine this script (the filename should probably match the filename in the remote newsfeeds entry) and send the batch to the remote site (using batcher, often called by send-uucp or sendbatch). Feeding a large number of sites

Innd tries to keep as many batchfiles open for as long as possible. It will normally open as many as it can, using all the available descriptors minus a fixed number for internal use (log files, etc.). You can explicitly set the number of files to open by using the ``-o'' flag.

If you have more outgoing feeds than available descriptors, innd will recycle the files on a a ``least recently used'' basis. If most of your feeds get most articles (or you have vastly more feeds then available descriptors), this will lead to ``file thrashing,'' closing and opening all the excess feeds on each article. To reduce this, you can have innd use an internal buffer for a site by using the ``I'' parameter in the newsfeeds file. If a site does not have its batchfile open, the server will not try to open it until there is more data to be written then will fit in the buffer. For example, suppose innd was started with ``-o10'' and there are 12 sites, all with ``I512'' in their newsfeeds entry. If each article generates 50 bytes (a pathname and a Message-ID), then innd will close and re-assign two descriptors every 10 or so articles.

A better alternative is to use funnels and an exploder. Funnels, specified in the newsfeeds 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.)

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, filechan and buffchan.

Filechan 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 inews. It can, however, be used as the funnel for an unlimited number of sites.

Buffchan keeps all its output files open all the time. It should not be used for more sites then a single process can have open. Buffchan 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 nntplink in its ``watch the batchfile'' mode.) Using buffchan with the ``-l1 -c50'' flags will give behavior that is similar to the C News relaynews.

Buffchan can be run as a full exploder (``Tx'') in the newsfeeds file. This means that you can use ctlinnd to send a command line down buffchan's input stream. (Innd 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. Master/slave replication

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 — this includes both outside newsfeeds and articles written by local users. The slaves only receive articles from the master.

No special work is required to set up a master host.

A slave is set up by starting innd 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 _PATH_NEWSBOOT script. If innd is started with the ``-S'' flag it will pass this flag on to nnrpd. This means that when anyone connects to the slave and does a ``POST'' command, nnrpd will connect to the master and offer the article.

You must make sure that the slave's entry in the master's newsfeeds file sends all articles (e.g., don't have any exclusions). Since the nnrpd on the slave host will usually add its name to the Path header, you should add ``Ap'' to the flags field of the slave's entry on the master.

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 documented in innd.8. In order to do this you will have to set up a newsfeeds 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 flags field of the entry.

When you want to actually send the articles to the slave site you will have to specify the ``-S'' flag in your innxmit command. Current versions of nntplink use the ``-x'' flag.

When running as a slave, innd 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.

Finally, note that postings made on the slave (via nnrpd) are actualy sent to the innd on the master, so the slave must be treated as a sending host, not a newsreading host.

Appendix IV: First-time Usenet or NNTP Installation

Since the needs and administration of systems varies so much, I can only give some general guidelines and advice in this section. Like 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.admin.misc''; use ``news.software.nntp'' and ``news.software.b'' for installation problems.

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 nntpget 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.)

If you already have Usenet access, you could post a note to ``news.admin.misc'' 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 <nntp-managers@colossus.apple.com> 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, not nntp-managers!)

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. The location of the active file is system-dependent, but the manpage should tell you (or the other administrator) where it is, often within the first paragraph. If your feed can't send you their active file, then you might want to find a more competent feed! The following command will zap an active file, setting up the article numbers for a new site: sed <active.old >active.new \
   -e 's/^\([^ ]*\) [0-9]* [0-9]* \([^ ]*\)$/\1 0000000000 0000000001 \2/'

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. Innd will accept the connection, receive the articles, and queue them up for any sites that you feed.

The next step is to set it up so that your articles are sent back to your newsfeed. To do this, create a newsfeeds 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.

When someone at your site writes an article, innd will record the filename in the batch file for your upstream site. Either send-nntp or nntpsend will flush and lock the batchfile, and then call innxmit 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 cron to run this script on a regular basis. You can run it as often as you like, but 10 minutes is a common interval.

If you want to feed any sites via UUCP, then you will have to set up file feed entries for them in the newsfeeds file, and arrange to have cron run the send-uucp script as desired. (UUCP batches are typically only done every few hours.)

Once you have news flowing in and out of the system, you will have to expire it or your disks will fill up. The news.daily script should be run by cron in the middle of the night. It will summarize that day's log files, and then call expire to purge old news. You might also want to have cron run rnews 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 innd does not currently time-out DNS entries.

You will generally want to set up the cron jobs so that they are run as the news administrator, and not as root. A good version of cron that makes it easy to do this can be found on gatekeeper.dec.com in pub/misc/vixie/cron.tar.Z. Use this if needed.

You will also need to get one or more programs to read news. There are several freely-available programs around. Rn is popular, and is probably the best place to start. The official distribution is available for anonymous FTP at tmc.edu in the rn directory.

Welcome to Usenet, and have fun!

Appendix V: News overview database

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 nn, trn, and gnus, 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.

In late 1992, Geoff Collyer <geoff@world.std.com> released the nov, or ``news overview,'' package. This included database tools 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 _PATH_OVERVIEWDIR parameter.

INN includes full support for creating and expiring news overview databases. To do this, add an entry like the following to your newsfeeds file: overview:*:Tc,WO:/path/to/bin/overchan (Make sure to replace /path/to/bin with the value of your _PATH_NEWSBIN parameter.) Then reload the newsfeeds file or restart your server. To create the initial database, run the following command after you have started overchan: expireover -a -s You will also need to expire the overview data. The easiest way to do this is to add the ``expireover'' keyword to the cron job that runs news.daily.

The nnrpd server includes two command extensions to access the database; they are documented in the ``PROTOCOL DIFFERENCES'' part of doc/nnrpd.8. 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 reader.dist.tar.Z.

Appendix VI: Limited MIME Support

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 nnrpd can add MIME headers to all local postings that do not have them.

In addition, there are patches available for nntplink that allow it to do MIME transport. The patches are not (yet) part of the official release; if you need them, contact Christophe Wolfhugel <Christophe.Wolfhugel@hsc-sec.fr>; he did most of the INN work, too.

You should be very careful if you have nnrpd add MIME headers. To do this, edit inn.conf as indicated in doc/inn.conf.5. Once this is done, all 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 inn.conf are these: mime-version: 1.0 mime-contenttype: text/plain; charset=us-ascii mime-encoding: 7bit An internationalized site might want to use these values: mime-version: 1.0 mime-contenttype: text/plain; charset=iso-8859-1 mime-encoding: 8bit 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 nnrpd is not a Mime-compatible reader. You must have software to extract the data and present it appropriately.

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. Nnrpd 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.

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 nnrpd does not do any conversion.

In general, be very cautious.

MIME articles can only be sent using innxmit. 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 forwarded in ``quoted-printable'' format (the ``base64'' format is not supported yet). 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.