Provided by: nn_6.7.2-1_i386 bug

NAME

       nnmaster - nn database manager

SYNOPSIS

       nnmaster -I [lmit]
       nnmaster -w
       nnmaster -v
       nnmaster -l [ "lock message" ]
       nnmaster [ options ] [ groups ]
       nnmaster -F [ options ] [ groups ]

DESCRIPTION

       nnmaster   is   the  daemon  which  is  responsible  for  building  and
       maintaining the database used by the nn(1) news reader.

       Normally, nnmaster is started when the system enters  multi-user  mode,
       and  runs  until system shutdown.  To facilitate this, you should place
       the following call in /etc/rc  (or  similar)  to  invoke  the  nnmaster
       daemon:
            $master/nnmaster -l -r -C
       where  $master  is the MASTER_DIRECTORY defined during configuration of
       nn.

       When nnmaster is started as specified above, it will first  unlock  the
       database  in  case  it  was locked (-l), perform a thorough consistency
       check on the database (-C).

       Then, every 10 minutes (-r), it will look at the time-stamp of the news
       active  file to see whether new articles have arrived on the system (or
       whether articles have been expired). (See -U)

       If the active file has been modified, nnmaster will collect the  header
       information  from the new articles and enter them into the database (or
       remove the headers of the expired articles from the database).

       If  it  detects  that  some  articles  have  been  expired,   it   will
       automatically  remove  the  header  information of the expired articles
       from the database.

ARTICLE COLLECTION OPTIONS

       Normally, nnmaster will collect all available news  groups  defined  in
       the  news  active  file.  The set of collected groups can be controlled
       via the argument line.  Groups can be either included or excluded:
       A group name, e.g. comp, will cause the group and all its subgroups  to
       be  collected.   Individual  groups, e.g. news.software.nn, can also be
       specified
       A group name preceded by an exclamation mark, e.g. !talk.politics, will
       cause the group and all its subgroups to be ignored.
       An  empty argument, i.e. "", will cause all groups that are not ignored
       to be collected.  For example, to collect everything but rec and  misc,
       use the following command:
            nnmaster -r !rec !misc ""
       If  the  empty  argument  had been omitted, nothing would be collected,
       since the presence of any groups arguments causes  nnmaster  to  ignore
       all groups which are not explicitly mentioned.
       Example  1:  The  following commands can be executed by cron to collect
       different sets of groups at  different  intervals  or  under  different
       conditions:
            nnmaster -B -O14 rec misc sci -LBO -u
            nnmaster !rec !misc !sci "" -u
       Example  2: The group arguments are used in the given sequence, e.g. to
       leave out comp.sys, but still collect comp.sys.ibm.pc, use the command:
            nnmaster -r comp.sys.ibm.pc !comp.sys ""
       The  use of the -u option in the first example is essential, since each
       of the commands will update the  active  file  time  stamp  which  will
       prevent  the  other  command  from  detecting  new  articles  that have
       arrived.
       Using this method to keep specific groups out of the database  must  be
       used  with  great caution; just a single invocation of nnmaster without
       any arguments will collect all the otherwise ignored groups!

COLLECTION OF ARTICLES

       The following options control how nnmaster performs the  collection  of
       new articles.

       -r [ min ]
              Daemon  mode.   The  nnmaster  will put itself in the background
              (unless -f is also specified), and will checks  for  arrival  of
              new  articles and expired articles every min minutes (and update
              the database accordingly).  If min is omitted, the default is to
              check every 10 minutes.
              Without  the  -r option, the nnmaster will just perform a single
              collection of new articles (if any) and then exit.  This can  be
              used  to  have  the  nnmaster  started  by  cron(8)  at  regular
              intervals instead of having it as a daemon which sleeps  between
              checking  for  new  articles.   Since  the  nnmaster  is  a  bit
              expensive to start up (it has to read a few files), it is up  to
              you  to  decide which mode is best on your system.  (I have also
              heard that it works to call nnmaster without -r  from  inews(1).
              I  cannot  recommend  this  unless  you  receive  batched  news;
              invoking  nnmaster  for  every  received  article   sounds   too
              expensive to me.)

       -h [ sec ]
              Hold  collection of new articles until next scan if new articles
              have arrived withing the last sec [60] seconds.  This is  useful
              to  prevent  nnmaster  from competing for disk i/o with an rnews
              process which is unbatching incoming news, or a  running  expire
              process.  It will have the side effect of limiting the number of
              C: entries in the log, since collection of incoming batches will
              typically be done in larger thunks.

       -f     Run  nnmaster  in foreground in daemon mode (see -r).  Useful if
              nnmaster is invoked from inittab.  (Notice that  if  you  use  a
              respawn  entry in inittab, you will not be able to stop nnmaster
              using the -k option, since init will immediately  start  another
              master.)

       -C     Perform  a  consistency  check  on the database on start-up, and
              rebuild corrupted database files.  This operation can  be  quite
              time-consuming since it reads through all the database files.

       -b     Normally,  articles without a proper news header (no Newsgroups:
              line) are ignored.  Specifying the -b option causes these  ‘bad’
              articles to be included in the database (normally with no sender
              or subject).

       -B     Remove ‘bad’ articles.  Sometimes,  articles  without  a  header
              ends  up  in  the  news spool directory.  These articles have no
              article id,  and  therefore,  they  will  never  be  expired  by
              expire(8).   This  option  will  allow  the nnmaster to silently
              remove these articles (a ‘B’ entry will occur in the log  file).

       -O days
              Ignore  articles  which are older than the given number of days.
              This may help keep old ’stray’ articles out of the database.  If
              the  -B  options  is  also  specified,  the old articles will be
              removed from the news spool directories.  Old ignored or removed
              articles  will  be  reported  with an ‘O’ entry in the log file.
              This option can be disable for individual groups by the  O  flag
              in the GROUPS file (see below).

       -R N   Specifies  how  the auto-recollect operation is performed on the
              groups having this option set in the GROUPS  file  (see  below).
              Four methods are available (default is method 1):
              1:  Run expire on the group when new articles arrive.
              2:  Run expire on the group on every scan.
              3:  Recollect all articles when new articles arrive.
              4:  Recollect all articles on every scan.

       -M mode
              Normally,  nnmaster  will  send  a  message via mail to the news
              administrator  (OWNER)  when  an  error  or  potential  problems
              (primarily  nntp related) occur.  This can be restricted to only
              fatal errors (nnmaster terminated) if mode is  1,  and  disabled
              completely if mode is 0.

       -Q     Normally, nnmaster will print a message on the system console or
              in the syslog if  a  fatal  error  happens.   This  option  will
              prevent  this,  so  only  a type ’E’ entry is written to the Log
              file.

DATABASE EXPIRATION

       Since articles does not stay forever in the news system,  the  database
       must  be  cleaned  up  regularly  to  remove the information stored for
       expired articles.  Expiration of the  database  is  normally  scheduled
       using  the nnadmin(1M) command executed by cron at a suitable time when
       expire on the news articles has completed.  The following command  will
       send  a  message to the nnmaster and cause it to initiate expire on all
       news groups:
            nnadmin =EYW

       Selective expiration of individual groups  can  be  done  from  nnadmin
       (interactive  mode).  It can also be done by invoking nnmaster with the
       -F option.  For example, the following command will run expire  on  all
       groups except the ‘rec’ groups:
            nnmaster -F -k !rec ""
       The  -k  option  is  required to terminate the currently running master
       since two daemons cannot be running at the  same  time.   Thus  to  run
       expire  (on  all  groups) in this way from cron, the following commands
       must be used:      nnmaster -Fk "" ; nnmaster -r ...

       It is also possible to have nnmaster  detect  expiration  automatically
       (see  -e).   This  requires  that  the  min field in the active file is
       updated by the news expire (this is not the default case when Cnews  is
       used).   However,  this is not always a safe indication since the first
       article may not have been expired, while a lot of other  articles  have
       been deleted.

       There  are  several  strategies  available  in  the nnmaster to do this
       clean-up, each having their strengths and weaknesses.

       Method 1 (default):  Rebuilds the database from the  existing  database
       information  by  comparing  the  current  database  contents  with  the
       contents of the news group directories, eliminating entries whose  file
       no  longer  exists.  This method is guaranteed to eliminate all expired
       articles from the database, and it is reasonably fast because  it  only
       has to read the directories, not each article file.
         If  news is accessed remotely via nntp, the list of existing articles
       cannot efficiently be fetched by reading a local directory.  Instead an
       XHDR request is sent to the nntp server to get a list of articles.

       Method  2:   Eliminates  only  the  expired  articles  before the first
       article in the group.  This is very fast since only the active file and
       the  database  itself  is  accessed,  but  it will obviously leave some
       expired articles in the database.  This method requires  that  the  min
       field in the active file is updated by expire.

       Method  3:  Discard the current database information and recollects all
       articles.  This is obviously very time consuming, and it  is  therefore
       not recommended, especially not with nntp.

       The options related to database expiration are:

       -E N   Select expire method N.  (If N is omitted, the default method is
              used).

       -e [N] Automatically run expire in the database on groups where the min
              number  in  the  active  file  has increased by N (1 if omitted)
              articles.  This is disabled by default (since the min  field  is
              often unreliable).

       -F     Run  expire  once and exit.  If a list of groups is specified on
              the command line, the matched groups (see the rules above)  will
              be  marked for expiration.  If no groups are specified, only the
              groups  already  scheduled   for   expire   will   be   expired.
              Consequently,   to  expire  all  groups,  a  blank  argument  ""
              (matching all groups) must be specified.

DATABASE LOCKING

       The database can be locked centrally, which will normally disallow  all
       access   to   the   database,   and  even  block  nnmaster  from  being
       (accidentally) started.  When a  lock  is  set  on  the  database,  all
       currently  running  clients  will  terminate  the next time they try to
       access the database.  Setting a lock on the database can thus  also  be
       used to force running clients to terminate.

       The following options set and clear locks on the database:

       -l message
              Locks  the database with the given message.  The message will be
              displayed every time a program tries to access the database.

       -l     Unlock the database if it was locked.

       -i     Ignore a possible lock and continue.  This can be used  to  have
              nnmaster operate on a database which is blocked from normal user
              access.

       Since only one nnmaster can operate on the database at any one time,  a
       running nnmaster daemon must be stopped before a lock can be set on the
       database.  If neither -f nor -r is specified with  the  -l  option  (in
       both  forms),  nnmaster  will  terminate  after setting or clearing the
       lock.

DATABASE INITIALIZATION

       The following options are used to initialize  and  update  the  central
       database files:

       -I [limit]
              Initialize   database.   This  option  will  erase  an  existing
              database, and create an empty database  containing  entries  for
              the  currently  known groups.  nnmaster will offer you to use an
              existing GROUPS file when initializing the database.
              The optional limit can be used to put a limit on the  number  of
              articles  that  will be collected in each group during the first
              collection of articles following  the  database  initialization.
              This  is  useful  on systems where the ’min’ field in the active
              file is unreliable or not maintained (Cnews  doesn’t)  to  limit
              the  work  done  to  do the initial collection of news after the
              initialization of the database.  If news  is  accessed  remotely
              from  an  NNTP server, this is even more important!  If limit is
              omitted, or is zero, nnmaster  will  trust  the  min  field  and
              collect all articles in the range min..last.

       -G     Reread  the  GROUPS  file.   This  option  is  used  to instruct
              nnmaster to parse the GROUPS file after it has been edited.  See
              the section on the GROUPS file below.

MISCELLANEOUS OPTIONS

       The  following  options  controls  various  details  of  the nnmaster’s
       behaviour:

       -D [ N ]
              Run nnmaster in "debug mode".  If N is omitted, or equals  1  or
              3,  this will produce a compact but still very informative trace
              of the collection or expire process directly  on  the  terminal.
              This  is most useful when doing the first collection of articles
              after initializing the database with -I.  If N  is  2  or  3,  a
              trace  of  the NNTP traffic is written to a file nnmaster.log in
              the TMP directory. This option disables -r.

       -H     Identifies the host which nnmaster is running on  as  the  nntp-
              server  for  its clients, i.e. that it can access the news spool
              directory locally without using NNTP.  Normally,  nnmaster  will
              detect this by itself by comparing the host name to the contents
              of the  nntp_server  file,  so  this  option  should  really  be
              superfluous.

       -y retries
              In  some  networked environment, opening an article (shared from
              another machine via NFS) may fail for no obvious reason.   Using
              this option, it is possible to cause nnmaster to perform retries
              attempts to open an article before marking the article  as  non-
              existing in the database.

       -L types
              Exclude  the  specified  entry types from the log file.  This is
              normally used to exclude the ’C’ollecting and  e’X’pire  entries
              (-LCXO).

       -t     Trace  the  collection  process.   This  will  place  a  lot  of
              information into the log file (T: entries).

       -u     Normally, nnmaster will  just  compare  the  time-stamp  on  the
              active  file  with  a time-stamp saved in the database to see if
              new articles have arrived.  The -u option forces the nnmaster to
              read  the  active  file  on start-up to see if new articles have
              arrived.

       -U     Some SVR4 systems (and maybe SunOS)  have  a  useful  "feature".
              Writing  files  with  mmap()  may  not  update  the last-changed
              timestamp on the file.  Since INN uses mmap()  for  writing  the
              active file, this becomes a problem for nnmaster.  The -U option
              causes nnmaster to unconditionally read  the  active  file  each
              time the repeat delay (-r) time expires.

       -v     Print  the  release and version identification for nnmaster, and
              exit.

       -w     Wakeup the real nnmaster.  Send a signal to the nnmaster  daemon
              to have it check for new articles immediately.

       -k     Kill  the already running nnmaster daemon before proceeding with
              the operation specified by the other options (or terminate if no
              other operation is requested).

THE GROUPS FILE

       The  primary  purpose  of  the GROUPS file is to store the names of the
       news groups represented  in  the  database.   Each  line  in  the  file
       corresponds  to  an entry in the (binary) MASTER file, and the sequence
       of the lines in the GROUPS  file  must  never  be  changed  unless  the
       database is reinitialized afterwards.

       However,  the contents of the lines in the GROUPS file can be edited to
       control how the nnmaster should handle each individual group.

       The format of each line is:
            news.group.name [ timestamp ] [ flags ]

       The news group name is the name of the group, and must not  be  changed
       in  any  way.   If  the group is no longer in the news active file, and
       consequently the group does no longer exist, group name can be replaced
       by  a  ‘@’  character which will instruct nnmaster to ignore this entry
       without having to rebuild the entire database.

       The optional time stamp indicates when the line was added to the GROUPS
       file  and  is used by nn to detect new groups.  When the GROUPS file is
       built initially from the active file, the time stamps are omitted which
       simply means that they are "old".

       One  or  more of the following flags can be added to the GROUPS line to
       control nnmaster’s handling of the group:

       D      Causes nnmaster to treat all articles in the group  as  digests,
              even  when  they  don’t  initially  look like digests.  Articles
              which are found not to be  digests  after  all,  are  still  not
              digested.

       N      Instructs nnmaster to never digest any articles in the group.

       O      Disables  the  -O  option  for  this  group,  i.e.  all existing
              articles will be included in the database (and they will not  be
              removed if the -B option is specified).  This flag should be set
              on groups which you never expire, or have  a  very  long  expire
              time!

       R      Causes nnmaster to recollect all available articles in the group
              whenever a new article is received.  This is said to  be  useful
              is   some  high-traffic  clarinet  groups  with  many  cancelled
              articles.

       >file  Instructs nnmaster to append all new articles to  the  specified
              file.  This makes it possible to keep specific groups out of the
              way of expire.  The archive file can be access directly from the
              nn client using the goto-group command.  The file name must be a
              full path name to a file in an existing, writeable directory.

       @      Instructs nnmaster to completely ignore this  group  -  this  is
              equivalent  to setting the group name to ‘@’ as described above.

       ! or X Causes nnmaster to ignore the group and not collect the  group’s
              articles in the database.

       Comments  (starting  with  ‘#’  and  continuing to the end of line) and
       empty  lines  are  allow  in  the  GROUPS  file,  but  it  is  strongly
       recommended  to  keep  the  changes  to  the  GROUPS  file  as small as
       possible, because of the implicit correspondence with the binary MASTER
       file.

       It is not recommended to edit the GROUPS file while nnmaster is running
       because it may add new groups to the file.  After  editing  the  GROUPS
       file, the command
            nnmaster -G
       must  be run before restarting the nnmaster to parse and verify the new
       GROUPS file.

NNTP SUPPORT

       The nnmaster can access the news  articles  from  a  local  news  spool
       directory  as  well  as  from  an NNTP server.  When compiled with NNTP
       enabled, nnmaster will compare the name of the NNTP server and the name
       of the local host; if they are identical, nnmaster will bypass NNTP and
       access the articles directly.

       When it has to access the news articles via NNTP, it cannot  time-stamp
       the  active  file,  so instead it transfers the entire active file from
       the NNTP server and compares it with a local copy of  the  last  active
       file fetched from the NNTP server.  This is not very expensive in terms
       of cpu-cycles, disk-load, or net-bandwidth, but  to  stay  on  friendly
       terms  with  the NNTP server administrator, you should probably not use
       shorter update intervals than the standard 10 minutes.

       Setting a much higher update interval than the standard 10  minutes  is
       not  really  recommended  either,  since  an  update  normally  implies
       fetching a burst of news articles from the NNTP server, so setting  the
       interval  too  long  may imply that the load on the NNTP server will be
       more un-even.

       In expire method 1, the use of XHDR just to  get  a  list  of  existing
       articles  in  a  group  is  definitely a waste of resources on the nntp
       server (but still lower than using method 3).  Before  using  the  XHDR
       request,  nnmaster will send a non-standard "LISTGROUP" request; if the
       nntp server supports this request, it should return an  OK_HEAD  status
       followed  by  an  (unordered)  list  of  article numbers (one per line)
       terminated by a ‘.’ line.  The nntp  servers  supporting  this  request
       will be much less loaded during expire.

       The  -O  option  does not work with NNTP.  The -B option will only work
       with NNTP if the nnmaster is running on the NNTP server.

FILES

       The $db, $master, and $news names  used  below  are  synonyms  for  the
       DB_DIRECTORY,  MASTER_DIRECTORY,  and NEWS_LIB_DIRECTORY defined during
       configuration.

       $db/MASTER          Database master index
       $db/GROUPS          News group names and flags in MASTER file order
       $db/DATA/nnn.[dx]   Database files for group number nnn
       .../.nn[dx]         Database files if located in the group directories
       $master/GATE        Message channel from nnadmin to nnmaster
       $master/MPID        The process id of the nnmaster daemon.
       $Log                The  log  file  (the  location   is   configuration
       dependent)
       $news/active        Existing articles and groups
       /usr/lib/nntp_serverContains the name of the NNTP server.

       The MASTER file contains a record for each news group, occurring in the
       same sequence as the group names in the GROUPS file.  The sequence also
       defines  the group numbers used to identify the files in the database’s
       DATA directory.

       The GATE file will be created by nnadmin when needed,  and  removed  by
       nnmaster  when  it  has  read  it.  Therefore, to send a message to the
       nnmaster requires  that  you  are  allowed  to  write  in  the  $master
       directory.

       The contents of the Log file are described in the nnadmin manual.

SEE ALSO

       nn(1), nncheck(1), nngrep(1), nntidy(1)
       nnadmin(1M), nnspew(8), nnusage(1M)

AUTHOR

       Kim F. Storm, Texas Instruments A/S, Denmark
       E-mail: storm@texas.dk