imapfeed(8)
NAME
innfeed, imapfeed - Multi-host, multi-connection, streaming NNTP feeder
SYNOPSIS
innfeed [-ChmMvxyz] [-a spool-dir] [-b directory] [-c config-file] [-d log-level] [-e bytes] [-l logfile] [-o bytes] [-p pid-file] [-s command] [-S status-file] [file]
DESCRIPTION
innfeed implements the NNTP protocol for transferring news between computers. It handles the standard IHAVE protocol as well as the CHECK/TAKETHIS streaming extension. innfeed can feed any number of remote hosts at once and will open multiple connections to each host if configured to do so. The only limitations are the process limits for open file descriptors and memory. As an alternative to using NNTP, INN may also be fed to an IMAP server. This is done by using an executable called imapfeed, which is identical to innfeed except for the delivery process. The new version has two types of connections: an LMTP connection to deliver regular messages and an IMAP connection to handle control messages.
MODES
innfeed has three modes of operation: channel, funnel-file and batch.
Channel mode is used when no filename is given on the command line, the
input-file keyword is not given in the config file, and the -x option
is not given. In channel mode, innfeed runs with stdin connected via a
pipe to innd. Whenever innd closes this pipe (and it has several
reasons during normal processing to do so), innfeed will exit. It
first will try to finish sending all articles it was in the middle of
transmitting, before issuing a QUIT command. This means innfeed may
take a while to exit depending on how slow your peers are. It never
(well, almost never) just drops the connection. The recommended way to
restart innfeed when run in channel mode is therefore to tell innd to
close the pipe and spawn a new innfeed process. This can be done with
"ctlinnd flush feed" where feed is the name of the innfeed channel feed
in the newsfeeds file.
Funnel-file mode is used when a filename is given as an argument or the
input-file keyword is given in the config file. In funnel-file mode,
it reads the specified file for the same formatted information as innd
would give in channel mode. It is expected that innd is continually
writing to this file, so when innfeed reaches the end of the file, it
will check periodically for new information. To prevent the funnel
file from growing without bounds, you will need to periodically move
the file to the side (or simply remove it) and have innd flush the
file. Then, after the file is flushed by innd, you can send innfeed a
SIGALRM, and it too will close the file and open the new file created
by innd. Something like:
innfeed -p <pathrun in inn.conf>/innfeed.pid my-funnel-file &
while true; do
sleep 43200
rm -f my-funnel-file
ctlinnd flush funnel-file-site
kill -ALRM `cat <pathrun>/innfeed.pid`
done
Batch mode is used when the -x flag is used. In batch mode, innfeed
will ignore stdin, and will simply process any backlog created by a
previously running innfeed. This mode is not normally needed as
innfeed will take care of backlog processing.
CONFIGURATION
innfeed expects a couple of things to be able to run correctly: a directory where it can store backlog files and a configuration file to describe which peers it should handle. The configuration file is described in innfeed.conf(5). The -c option can be used to specify a different file. For each peer (say, "foo"), innfeed manages up to 4 files in the backlog directory: * A foo.lock file, which prevents other instances of innfeed from interfering with this one. * A foo.input file which has old article information innfeed is reading for re-processing. * A foo.output file where innfeed is writing information on articles that could not be processed (normally due to a slow or blocked peer). * A foo file that is never created by innfeed, but if innfeed notices it, it will rename it to foo.input at the next opportunity and will start reading from it. This lets you create a batch file and put it in a place where innfeed will find it. You should never alter the foo.input or foo.output files of a running innfeed. The format of these last three files is one of the following: /path/to/article <message-id> @token@ <message-id> This is the same as the first two fields of the lines innd feeds to innfeed, and the same as the first two fields of the lines of the batch file innd will write if innfeed is unavailable for some reason. When innfeed processes its own batch files, it ignores everything after the first two whitespace separated fields, so moving the innd-created batch file to the appropriate spot will work, even though the lines have extra fields. The first field can also be a storage API token. The two types of lines can be intermingled; innfeed will use the storage manager if appropriate, and otherwise treat the first field as a filename to read directly. innfeed writes its current status to the file innfeed.status (or the file given by the -S option). This file contains details on the process as a whole, and on each peer this instance of innfeed is managing. If innfeed is told to send an article to a host it is not managing, then the article information will be put into a file matching the pattern innfeed-dropped.*, with part of the file name matching the pid of the innfeed process that is writing to it. innfeed will not process this file except to write to it. If nothing is written to the file, then it will be removed if innfeed exits normally. Otherwise, the file remains, and procbatch can be invoked to process it afterwards.
SIGNALS
Upon receipt of a SIGALRM, innfeed will close the funnel file specified on the command line, and will reopen it (see funnel file description above). innfeed with catch SIGINT and will write a large debugging snapshot of the state of the running system. innfeed will catch SIGHUP and will reload both the config and the log files. See innfeed.conf(5) for more details. innfeed will catch SIGCHLD and will close and reopen all backlog files. innfeed will catch SIGTERM and will do an orderly shutdown. Upon receipt of a SIGUSR1, innfeed will increment the debugging level by one; receipt of a SIGUSR2 will decrement it by one. The debugging level starts at zero (unless the -d option it used), in which case no debugging information is emitted. A larger value for the level means more debugging information. Numbers up to 5 are currently useful.
SYSLOG ENTRIES
There are 3 different categories of syslog entries for statistics:
host, connection and global.
The host statistics are generated for a given peer at regular intervals
after the first connection is made (or, if the remote is unreachable,
after spooling starts). The host statistics give totals over all
connections that have been active during the given time frame. For
example (broken here to fit the page, with "vixie" being the peer):
May 23 12:49:08 news innfeed[16015]: vixie checkpoint
seconds 1381 offered 2744 accepted 1286 refused 1021 rejected 437
missing 0 accsize 8506220 rejsize 142129 spooled 990
on_close 0 unspooled 240 deferred 10/15.3 requeued 25
queue 42.1/100:14,35,13,4,24,10
The meanings of these fields are:
seconds
The time since innfeed connected to the host or since the statistics
were reset by a "final" log entry.
offered
The number of IHAVE commands sent to the host if it is not in
streaming mode. The sum of the number of TAKETHIS commands sent when
no-CHECK mode is in effect plus the number of CHECK commands sent in
streaming mode (when no-CHECK mode is not in effect).
accepted
The number of articles which were sent to the remote host and
accepted by it.
refused
The number of articles offered to the host that it indicated it did
not want because it had already seen the message-ID. The remote host
indicates this by sending a 435 response to an IHAVE command or a 438
response to a CHECK command.
rejected
The number of articles transferred to the host that it did not accept
because it determined either that it already had the article or it
did not want it because of the article's Newsgroups: or Distribution:
header fields, etc. The remote host indicates that it is rejecting
the article by sending a 437 or 439 response after innfeed sent the
entire article.
missing
The number of articles which innfeed was told to offer to the host
but which were not present in the article spool. These articles were
probably cancelled or expired before innfeed was able to offer them
to the host.
accsize
The number of bytes of all accepted articles transferred to the host.
rejsize
The number of bytes of all rejected articles transferred to the host.
spooled
The number of article entries that were written to the .output
backlog file because the articles either could not be sent to the
host or were refused by it. Articles are generally spooled either
because new articles are arriving more quickly than they can be
offered to the host, or because innfeed closed all the connections to
the host and pushed all the articles currently in progress to the
.output backlog file.
on_close
The number of articles that were spooled when innfeed closed all the
connections to the host.
unspooled
The number of article entries that were read from the .input backlog
file.
deferred
The first number is the number of articles that the host told innfeed
to retry later by sending a 431 or 436 response. innfeed immediately
puts these articles back on the tail of the queue.
The second number is the average (mean) size of deferred articles
during the previous logging interval
requeued
The number of articles that were in progress on connections when
innfeed dropped those connections and put the articles back on the
queue. These connections may have been broken by a network problem
or became unresponsive causing innfeed to time them out.
queue
The first number is the average (mean) queue size during the previous
logging interval. The second number is the maximum allowable queue
size. The third number is the percentage of the time that the queue
was empty. The fourth through seventh numbers are the percentages of
the time that the queue was >0% to 25% full, 25% to 50% full, 50% to
75% full, and 75% to <100% full. The last number is the percentage
of the time that the queue was totally full.
If the -z option is used (see below), then when the peer stats are
generated, each connection will log its stats too. For example, for
connection number zero (from a set of five):
May 23 12:49:08 news innfeed[16015]: vixie:0 checkpoint
seconds 1381 offered 596 accepted 274 refused 225
rejected 97 accsize 773623 rejsize 86591
If you only open a maximum of one connection to a remote, then there
will be a close correlation between connection numbers and host
numbers, but in general you cannot tie the two sets of number together
in any easy or very meaningful way. When a connection closes, it will
always log its stats.
If all connections for a host get closed together, then the host logs
its stats as "final" and resets its counters. If the feed is so busy
that there is always at least one connection open and running, then
after some amount of time (set via the config file), the host stats are
logged as final and reset. This is to make generating higher level
stats from log files, by other programs, easier.
There is one log entry that is emitted for a host just after its last
connection closes and innfeed is preparing to exit. This entry
contains counts over the entire life of the process. The "seconds"
field is from the first time a connection was successfully built, or
the first time spooling started. If a host has been completely idle,
it will have no such log entry.
May 23 12:49:08 news innfeed[16015]: decwrl global
seconds 1381 offered 34 accepted 22 refused 3 rejected 7
missing 0 accsize 81277 rejsize 12738 spooled 0 unspooled 0
The final log entry is emitted immediately before exiting. It contains
a summary of the statistics over the entire life of the process.
Feb 13 14:43:41 news innfeed[22344]: ME global
seconds 15742 offered 273441 accepted 45750 refused 222008
rejected 3334 missing 217 accsize 93647166 rejsize 7421839
spooled 10 unspooled 0
OPTIONS
innfeed takes the following options.
-a spool-dir
The -a flag is used to specify the top of the article spool tree.
innfeed does a chdir(2) to this directory, so it should probably be
an absolute path. The default is patharticles as set in inn.conf.
-b directory
The -b flag may be used to specify a different directory for
backlog file storage and retrieval, as well as for lock files. If
the path is relative, then it is relative to pathspool as set in
inn.conf. The default is "innfeed".
-c config-file
The -c flag may be used to specify a different config file from the
default value. If the path is relative, then it is relative to
pathetc as set in inn.conf. The default is innfeed.conf.
-C The -C flag is used to have innfeed simply check the config file,
report on any errors and then exit.
-d log-level
The -d flag may be used to specify the initial logging level. All
debugging messages go to stderr (which may not be what you want,
see the -l flag below).
-e bytes
The -e flag may be used to specify the size limit (in bytes) for
the .output backlog files innfeed creates. If the output file gets
bigger than 10% more than the given number, innfeed will replace
the output file with the tail of the original version. The default
value is 0, which means there is no limit.
-h Use the -h flag to print the usage message.
-l logfile
The -l flag may be used to specify a different log file from
stderr. As innd starts innfeed with stderr attached to /dev/null,
using this option can be useful in catching any abnormal error
messages, or any debugging messages (all "normal" errors messages
go to syslog).
-m The -m flag is used to turn on logging of all missing articles.
Normally, if an article is missing, innfeed keeps a count, but logs
no further information. When this flag is used, details about
message-IDs and expected path names are logged.
-M If innfeed has been built with mmap support, then the -M flag turns
OFF the use of mmap(); otherwise, it has no effect.
-o bytes
The -o flag sets a value of the maximum number of bytes of article
data innfeed is supposed to keep in memory. This does not work
properly yet.
-p pid-file
The -p flag is used to specify the file name to write the pid of
the process into. A relative path is relative to pathrun as set in
inn.conf. The default is innfeed.pid.
-s command
The -s flag specifies the name of a command to run in a subprocess
and read article information from. This is similar to channel mode
operation, only that command takes the place usually occupied by
innd.
-S status-file
The -S flag specifies the name of the file to write the periodic
status to. If the path is relative, it is considered relative to
pathlog as set in inn.conf. The default is innfeed.status.
-v When the -v flag is given, version information is printed to stderr
and then innfeed exits.
-x The -x flag is used to tell innfeed not to expect any article
information from innd but just to process any backlog files that
exist and then exit.
-y The -y flag is used to allow dynamic peer binding. If this flag is
used and article information is received from innd that specifies
an unknown peer, then the peer name is taken to be the IP name too,
and an association with it is created. Using this, it is possible
to only have the global defaults in the innfeed.conf file, provided
the peer name as used by innd is the same as the IP name.
Note that innfeed with -y and no peer in innfeed.conf would cause a
problem that innfeed drops the first article.
-z The -z flag is used to cause each connection, in a parallel feed
configuration, to report statistics when the controller for the
connections prints its statistics.
BUGS
When using the -x option, the config file entry's initial-connections field will be the total number of connections created and used, no matter how many big the batch file, and no matter how big the max- connections field specifies. Thus a value of 0 for initial-connections means nothing will happen in -x mode. innfeed does not automatically grab the file out of pathoutgoing. This needs to be prepared for it by external means. Probably too many other bugs to count.
ALTERNATIVE
An alternative to innfeed can be innduct, maintained by Ian Jackson and available at <http://www.chiark.greenend.org.uk/ucgi/~ian/git-manpage/innduct.git/innduct.8>. It is intended to solve a design issue in the way innfeed works. As a matter of fact, the program feed protocol spoken between innd and innfeed is lossy: if innfeed dies unexpectedly, articles which innd has written to the pipe to innfeed will be skipped. innd has no way of telling which articles those are, no useful records, and no attempts to resend these articles.
FILES
pathbin/innfeed
The binary program itself.
pathetc/innfeed.conf
The configuration file.
pathspool/innfeed
The directory for backlog files.
HISTORY
Written by James Brister <brister@vix.com> for InterNetNews. Converted to POD by Julien Elie. Earlier versions of innfeed (up to 0.10.1) were shipped separately; innfeed is now part of INN and shares the same version number. $Id: innfeed.pod 9588 2013-12-19 17:46:41Z iulius $
SEE ALSO
ctlinnd(8), inn.conf(5), innfeed.conf(5), innd(8), procbatch(8).
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