Ubuntu Manpage: expire.ctl - Configuration file for article expiration

Provided by: inn2_2.7.1~20230131-1build1_amd64

NAME

       expire.ctl - Configuration file for article expiration

DESCRIPTION

The file pathetc/expire.ctl is the default configuration file for expire and expireover,
which read it at start-up. It serves two purposes: it defines how long history entries
for expired or rejected articles are remembered, and it determines how long articles
stored on the server are retained.

Normally, if all of the storage methods used by the server are self-expiring (such as
CNFS), all lines except the "/remember/" setting (described below) are ignored. This can
be changed with the -N option to expire or expireover.

Blank lines and lines beginning with a number sign ("#") are ignored. All other lines
should be in one of two formats. The order of the file is significant, and the last
matching entry will be used.

The first format specifies how long to keep history entries for articles that aren't
present in the news spool. These are articles that have either already expired, or
articles which the server rejected (when remembertrash is set to true in inn.conf). There
should be one and only one line in this format, which looks like:

/remember/:<days>

where <days> is a decimal number that specifies the minimum number of days a history
record for a given Message-ID is retained (from its original posting time), regardless of
whether the article is present in the spool. (History entries for articles still present
in the spool are always retained.) Setting it to "never" means history records will be
retained forever, 0 means history records for articles not present in the spool will be
purged when expiry programs run. (This is notably useful in the case you need re-
injecting articles no longer present in your news spool but considered as duplicate,
because still present in history: you'll have to set "/remember/" to 0, run the expire
process for instance via news.daily called with the same parameters as in crontab plus
"notdaily", and undo the change in expire.ctl. All previously rejected or removed
articles will then not be considered as duplicate if their Message-ID is proposed.)

The primary reason to retain a record of old articles is in case a peer offers old
articles that were previously accepted but have already expired. Without a history record
for such articles, the server would accept the article again and readers would see
duplicate articles. Articles older than a certain number of days won't be accepted by the
server at all (see artcutoff in inn.conf(5) and the -c flag in innd(8)), and this setting
should probably match that time period to ensure that the server never accepts duplicates.
As the default value for artcutoff is 10 days, it means that "/remember/" should be set to
11 days in order to take into account articles whose posting date is one day into the
future.

Most of the lines in this file will be in the second format, which consists of either four
or five colon-separated fields:

if groupbaseexpiry is true in inn.conf (the default), and otherwise:

All lines must be in the correct format given the current setting of groupbaseexpiry, and
therefore the two formats cannot co-exist in the same file.

Normally, a rule matches a newsgroup through the combination of the <pattern> and <flag>
fields. <pattern> is a uwildmat-style pattern, specifying the newsgroups to which the
line is applied. Note that the last matching entry will be used, so general patterns
(such as defaults for all groups where <pattern> is "*") should appear at the beginning of
the file before more specific settings.

The <flag> field can be used to further limit newsgroups to which the line applies, and
should be chosen from the following set:

M Only moderated groups
U Only unmoderated groups
A All groups
X Remove the article from all groups it appears in

One of "M", "U", or "A" must be specified. "X" should be used in combination with one of
the other letters, not by itself.

An expiration policy is applied to every article in a newsgroup it matches. There is no
way to set an expiration policy for articles crossposted to groups you don't carry that's
different than other articles in the same group. Normally, articles are not completely
deleted until they expire out of every group to which they were posted, but if an article
is expired following a rule where <flag> contains "X", it is deleted out of all newsgroups
to which it was posted immediately. (If that behaviour is wanted for all rules, you may
want to give the -e flag to expireoverview.)

If groupbaseexpiry is instead set to false, there is no <pattern> and <flag> field and the
above does not apply. Instead, there is a single <classnum> field, which is either a
number matching the storage class number specified in storage.conf or "*" to specify a
default for all storage classes. All articles stored in a storage class will be expired
following the instructions in the line with a matching <classnum>, and when articles are
expired, they're always removed from all groups to which they were posted.

The remaining three fields are the same in either format, and are used to determine how
long an article should be kept from its original arrival time (unless the -p flag is
passed to expire(8) or expireover(8), in which case its original posting time is used).
Each field should be either a decimal number of days (fractions like 8.5 are allowed, but
remember that articles are only removed when expire or expireover is run, normally once a
day by news.daily) or the word "never".

The middle field, <default>, will be used as the expiration period for most articles. The
other two fields, <min> and <max>, only come into play if the article requests a
particular expiration date with an Expires header field. Articles with an Expires header
field will be expired at the date given in that header field, subject to the constraints
that they will be retained at least <min> days and no longer than <max> days.

If <min> is set to "never", no article matching that line will ever be expired. If
<default> is set to "never", no article matching that line without an explicit Expires
header field will ever be expired. If <max> is set to "never", Expires header fields will
be honored no matter how far into the future they are.

One should think of the fields as a lower bound, the default, and an upper bound. Since
most articles do not have an Expires header field, the second field is the most important
and most commonly applied.

Articles that do not match any expiration rule will not be expired, but this is considered
an error and will result in a warning. There should always be a default line (a line with
a <pattern> of "*" and <flag> of "A", or a line with a <classnum> of "*"), which can
explicitly state that articles should never expire by default if that's the desired
configuration. The default line should generally be the first line of the file (except
for "/remember/") so that other expiration rules can override it.

It is often useful to honor the Expires header field in articles, especially those in
moderated groups. To do this, set <min> to zero, <default> to whatever normal expiration
you wish, and <max> to "never" or some large number, like 365 days for a maximum article
life of a year.

To ignore any Expires header field, set all three fields to the same value.

EXAMPLES

       When groupbaseexpiry is true (the default):

           # Keep expired article history for 11 days, matching artcutoff plus one.
           /remember/:11

           # Most articles stay for two weeks, ignoring Expires header fields.
           *:A:14:14:14

           # Accept Expires header fields in moderated groups for up to a year and
           # retain moderated groups for a bit longer.
           *:M:1:30:365

           # Keep local groups for a long time and local project groups forever.
           example.*:A:1:90:90
           example.project.*:A:never:never:never

       When groupbaseexpiry is false, for class-based expiration:

           # Keep expired article history for 11 days, matching artcutoff plus one.
           /remember/:11

           # Set a default expiration of seven days and honour Expires header fields
           # within reasonable limits.
           *:1:7:35

           # Class 0 is retained for two weeks and honor Expires header fields
           # within reasonable limits.
           0:1:14:65

HISTORY

       Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews.  Converted to POD by Russ
       Allbery <eagle@eyrie.org>.

NAME

DESCRIPTION

EXAMPLES

HISTORY

SEE ALSO