flush.8.html   [plain text]


<html> <head> </head> <body> <pre>
FLUSH(8)                                                 FLUSH(8)

<b>NAME</b>
       flush - Postfix fast flush server

<b>SYNOPSIS</b>
       <b>flush</b> [generic Postfix daemon options]

<b>DESCRIPTION</b>
       The  flush  server  maintains a record of deferred mail by
       destination.  This information is used to improve the per-
       formance of the SMTP <b>ETRN</b> request, and of its command-line
       equivalent, <b>sendmail</b> <b>-qR</b>.  This program expects to be  run
       from the <a href="master.8.html"><b>master</b>(8)</a> process manager.

       The  record  is  implemented  as a per-destination logfile
       with as contents the queue IDs of deferred mail. A logfile
       is   append-only,   and  is  truncated  when  delivery  is
       requested for the corresponding destination. A destination
       is  the part on the right-hand side of the right-most <b>@</b> in
       an email address.

       Per-destination logfiles of deferred mail  are  maintained
       only  for eligible destinations. The list of eligible des-
       tinations is specified with the <b>fast</b><i>_</i><b>flush</b><i>_</i><b>domains</b> config-
       uration parameter, which defaults to <b>$relay</b><i>_</i><b>domains</b>.

       This server implements the following requests:

       <b>FLUSH</b><i>_</i><b>REQ</b><i>_</i><b>ADD</b> <i>sitename</i> <i>queue_id</i>
              Inform  the  fast  flush  server that the specified
              message is queued for <i>sitename</i>. Depending  on  log-
              ging  policy,  the  fast  flush  server  stores  or
              ignores the information.

       <b>FLUSH</b><i>_</i><b>REQ</b><i>_</i><b>SEND</b> <i>sitename</i>
              Request delivery of mail that is queued  for  <i>site-</i>
              <i>name</i>.   If  the  destination is eligible for a fast
              flush logfile, this request  triggers  delivery  of
              messages  listed in that destination's logfile, and
              the logfile is truncated to zero length; if mail is
              undeliverable it will be added back to the logfile.

              If the destination is not eligible for a fast flush
              logfile,  this  request  is rejected (see below for
              status codes).

       <b>TRIGGER</b><i>_</i><b>REQ</b><i>_</i><b>WAKEUP</b>
              This wakeup request from the master is an  alterna-
              tive way to request <b>FLUSH</b><i>_</i><b>REQ</b><i>_</i><b>REFRESH</b>.

       <b>FLUSH</b><i>_</i><b>REQ</b><i>_</i><b>REFRESH</b> (completes in the background)
              Refresh  non-empty  per-destination  logfiles  that
              were not read in <b>fast</b><i>_</i><b>flush</b><i>_</i><b>refresh</b><i>_</i><b>time</b> hours,  by
              simulating send requests (see above) for the corre-
              sponding destinations.

              Delete empty per-destination logfiles that were not
              updated in <b>fast</b><i>_</i><b>flush</b><i>_</i><b>purge</b><i>_</i><b>time</b> days.

       <b>FLUSH</b><i>_</i><b>REQ</b><i>_</i><b>PURGE</b> (completes in the background)
              Refresh  all non-empty per-destination logfiles, by
              simulating send requests (see above) for the corre-
              sponding  destinations.   This  can  be  incredibly
              expensive when logging is enabled for many destina-
              tions, and is not recommended.

              Delete empty per-destination logfiles that were not
              updated in <b>fast</b><i>_</i><b>flush</b><i>_</i><b>purge</b><i>_</i><b>time</b> days.

       The server response is one of:

       <b>FLUSH</b><i>_</i><b>STAT</b><i>_</i><b>OK</b>
              The request completed normally.

       <b>FLUSH</b><i>_</i><b>STAT</b><i>_</i><b>BAD</b>
              The flush server rejected the request (bad  request
              name, bad request parameter value).

       <b>FLUSH</b><i>_</i><b>STAT</b><i>_</i><b>FAIL</b>
              The request failed.

       <b>FLUSH</b><i>_</i><b>STAT</b><i>_</i><b>DENY</b>
              The  request  was  denied  because  the destination
              domain is not eligible for fast flush  service,  or
              because the fast flush service is disabled.

<b>SECURITY</b>
       The  fast  flush server is not security-sensitive. It does
       not talk to the network, and it does  not  talk  to  local
       users.   The  fast  flush server can run chrooted at fixed
       low privilege.

<b>DIAGNOSTICS</b>
       Problems and transactions are logged to <b>syslogd</b>(8).

<b>BUGS</b>
       Fast  flush  logfiles   are   truncated   only   after   a
       <b>FLUSH</b><i>_</i><b>REQ</b><i>_</i><b>SEND</b>  request,  not when mail is actually deliv-
       ered, and therefore can accumulate outdated  or  redundant
       data.  In order to maintain sanity, <b>FLUSH</b><i>_</i><b>REQ</b><i>_</i><b>REFRESH</b> must
       be executed periodically. This can  be  automated  with  a
       suitable  wakeup timer setting in the <b>master.cf</b> configura-
       tion file.

       Upon receipt of a request to deliver all mail for an  eli-
       gible  destination,  the <b>flush</b> server requests delivery of
       all messages that are listed in  that  destination's  log-
       file, regardless of the recipients of those messages. This
       is not an issue for mail that is sent to  a  <b>relay</b><i>_</i><b>domains</b>
       destination  because  such mail typically only has recipi-
       ents in one domain.

<b>FILES</b>
       /var/spool/postfix/flush, location of "fast flush" logfiles.

<b>CONFIGURATION</b> <b>PARAMETERS</b>
       See the Postfix <b>main.cf</b> file for syntax  details  and  for
       default  values.  Use  the  <b>postfix</b> <b>reload</b> command after a
       configuration change.

       <b>fast</b><i>_</i><b>flush</b><i>_</i><b>domains</b>
              What destinations can have a "fast flush"  logfile.
              By default, this is set to <b>$relay</b><i>_</i><b>domains</b>.

       <b>fast</b><i>_</i><b>flush</b><i>_</i><b>refresh</b><i>_</i><b>time</b>
              Refresh  a  non-empty "fast flush" logfile that was
              not read in this amount of time (default time unit:
              hours), by simulating a send request for the corre-
              sponding destination.

       <b>fast</b><i>_</i><b>flush</b><i>_</i><b>purge</b><i>_</i><b>time</b>
              Remove an empty "fast flush" logfile that  was  not
              updated  in this amount of time (default time unit:
              days).

       <b>parent</b><i>_</i><b>domain</b><i>_</i><b>matches</b><i>_</i><b>subdomains</b>
              List of Postfix features that use  <i>domain.tld</i>  pat-
              terns   to  match  <i>sub.domain.tld</i>  (as  opposed  to
              requiring <i>.domain.tld</i> patterns).

<b>SEE</b> <b>ALSO</b>
       <a href="smtpd.8.html">smtpd(8)</a> Postfix SMTP server
       <a href="qmgr.8.html">qmgr(8)</a> Postfix queue manager
       syslogd(8) system logging

<b>LICENSE</b>
       The Secure Mailer license must be  distributed  with  this
       software.

<b>AUTHOR(S)</b>
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

                                                         FLUSH(8)
</pre> </body> </html>