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

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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 newsgroups for up to
           # a year, and retain moderated newsgroups for a bit longer.
           *:M:1:30:365

           # Keep local newsgroups for a long time and local project
           # newsgroups 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

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