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7FLUSH(8)                                                              FLUSH(8)
8
9<b>NAME</b>
10       flush - Postfix fast flush server
11
12<b>SYNOPSIS</b>
13       <b>flush</b> [generic Postfix daemon options]
14
15<b>DESCRIPTION</b>
16       The <a href="flush.8.html"><b>flush</b>(8)</a> server maintains a record of deferred mail by destination.
17       This information is used to improve the performance of  the  SMTP  <b>ETRN</b>
18       request,   and  of  its  command-line  equivalent,  "<b>sendmail  -qR</b>"  or
19       "<b>postqueue -f</b>".  This program expects to  be  run  from  the  <a href="master.8.html"><b>master</b>(8)</a>
20       process manager.
21
22       The record is implemented as a per-destination logfile with as contents
23       the queue IDs of deferred mail. A logfile is append-only, and is  trun-
24       cated  when  delivery is requested for the corresponding destination. A
25       destination is the part on the right-hand side of the right-most  <b>@</b>  in
26       an email address.
27
28       Per-destination  logfiles of deferred mail are maintained only for eli-
29       gible destinations. The list of eligible destinations is specified with
30       the  <b><a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a></b>  configuration  parameter,  which  defaults  to
31       <b>$<a href="postconf.5.html#relay_domains">relay_domains</a></b>.
32
33       This server implements the following requests:
34
35       <b>add</b> <i>sitename queueid</i>
36              Inform the <a href="flush.8.html"><b>flush</b>(8)</a> server that the message with  the  specified
37              queue ID is queued for the specified destination.
38
39       <b>send_site</b> <i>sitename</i>
40              Request delivery of mail that is queued for the specified desti-
41              nation.
42
43       <b>send_file</b> <i>queueid</i>
44              Request delivery of the specified deferred message.
45
46       <b>refresh</b>
47              Refresh non-empty per-destination logfiles that were not read in
48              <b>$<a href="postconf.5.html#fast_flush_refresh_time">fast_flush_refresh_time</a></b> hours, by simulating send requests (see
49              above) for the corresponding destinations.
50
51              Delete empty per-destination logfiles that were not  updated  in
52              <b>$<a href="postconf.5.html#fast_flush_purge_time">fast_flush_purge_time</a></b> days.
53
54              This request completes in the background.
55
56       <b>purge</b>  Do a <b>refresh</b> for all per-destination logfiles.
57
58<b>SECURITY</b>
59       The  <a href="flush.8.html"><b>flush</b>(8)</a> server is not security-sensitive. It does not talk to the
60       network, and it does not talk to local users.  The  fast  flush  server
61       can run chrooted at fixed low privilege.
62
63<b>DIAGNOSTICS</b>
64       Problems and transactions are logged to <b>syslogd</b>(8).
65
66<b>BUGS</b>
67       Fast flush logfiles are truncated only after a "send" request, not when
68       mail is actually delivered, and therefore can  accumulate  outdated  or
69       redundant data. In order to maintain sanity, "refresh" must be executed
70       periodically. This can be automated with a suitable wakeup  timer  set-
71       ting in the <a href="master.5.html"><b>master.cf</b></a> configuration file.
72
73       Upon  receipt of a request to deliver mail for an eligible destination,
74       the <a href="flush.8.html"><b>flush</b>(8)</a> server requests delivery of all messages that  are  listed
75       in  that  destination's  logfile, regardless of the recipients of those
76       messages. This is not an issue for mail that is sent to a <b><a href="postconf.5.html#relay_domains">relay_domains</a></b>
77       destination  because  such  mail  typically  only has recipients in one
78       domain.
79
80<b>CONFIGURATION PARAMETERS</b>
81       Changes to <a href="postconf.5.html"><b>main.cf</b></a> are picked up automatically  as  <a href="flush.8.html"><b>flush</b>(8)</a>  processes
82       run for only a limited amount of time. Use the command "<b>postfix reload</b>"
83       to speed up a change.
84
85       The text below provides only a parameter summary. See  <a href="postconf.5.html"><b>postconf</b>(5)</a>  for
86       more details including examples.
87
88       <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
89              The  default  location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a> con-
90              figuration files.
91
92       <b><a href="postconf.5.html#daemon_timeout">daemon_timeout</a> (18000s)</b>
93              How much time a Postfix daemon process  may  take  to  handle  a
94              request before it is terminated by a built-in watchdog timer.
95
96       <b><a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a> ($<a href="postconf.5.html#relay_domains">relay_domains</a>)</b>
97              Optional list of destinations that are eligible for per-destina-
98              tion logfiles with mail that is queued to those destinations.
99
100       <b><a href="postconf.5.html#fast_flush_refresh_time">fast_flush_refresh_time</a> (12h)</b>
101              The time after which  a  non-empty  but  unread  per-destination
102              "fast flush" logfile needs to be refreshed.
103
104       <b><a href="postconf.5.html#fast_flush_purge_time">fast_flush_purge_time</a> (7d)</b>
105              The  time after which an empty per-destination "fast flush" log-
106              file is deleted.
107
108       <b><a href="postconf.5.html#ipc_timeout">ipc_timeout</a> (3600s)</b>
109              The time limit for sending  or  receiving  information  over  an
110              internal communication channel.
111
112       <b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
113              The  maximum  amount of time that an idle Postfix daemon process
114              waits for an incoming connection before terminating voluntarily.
115
116       <b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
117              The maximal number of incoming connections that a Postfix daemon
118              process will service before terminating voluntarily.
119
120       <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> (see 'postconf -d' output)</b>
121              What Postfix features match subdomains of "domain.tld" automati-
122              cally, instead of requiring an explicit ".domain.tld" pattern.
123
124       <b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
125              The process ID of a Postfix command or daemon process.
126
127       <b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
128              The process name of a Postfix command or daemon process.
129
130       <b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
131              The location of the Postfix top-level queue directory.
132
133       <b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
134              The syslog facility of Postfix logging.
135
136       <b><a href="postconf.5.html#syslog_name">syslog_name</a> (see 'postconf -d' output)</b>
137              The  mail  system  name that is prepended to the process name in
138              syslog records, so that "smtpd"  becomes,  for  example,  "post-
139              fix/smtpd".
140
141<b>FILES</b>
142       /var/spool/postfix/flush, "fast flush" logfiles.
143
144<b>SEE ALSO</b>
145       <a href="smtpd.8.html">smtpd(8)</a>, SMTP server
146       <a href="qmgr.8.html">qmgr(8)</a>, queue manager
147       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
148       <a href="master.5.html">master(5)</a>, generic daemon options
149       <a href="master.8.html">master(8)</a>, process manager
150       syslogd(8), system logging
151
152<b>README FILES</b>
153       <a href="ETRN_README.html">ETRN_README</a>, Postfix ETRN howto
154
155<b>LICENSE</b>
156       The Secure Mailer license must be distributed with this software.
157
158<b>HISTORY</b>
159       This service was introduced with Postfix version 1.0.
160
161<b>AUTHOR(S)</b>
162       Wietse Venema
163       IBM T.J. Watson Research
164       P.O. Box 704
165       Yorktown Heights, NY 10598, USA
166
167                                                                      FLUSH(8)
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