Manual Pages for UNIX Darwin command on man flush

FLUSH(8) FLUSH(8)

NAME

flush - Postfix fast flush server

SYNOPSIS

fflluusshh [generic Postfix daemon options]

DESCRIPTION

The flush server maintains a record of deferred mail by destination.

This information is used to improve the performance of the SMTP EETTRRNN

request, and of its command-line equivalent, "sseennddmmaaiill -qqRR" or

"ppoossttqquueeuuee -ff". This program expects to be run from the mmaasstteerr(8)

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 trun-

cated when delivery is requested for the corresponding destination. A

destination is the part on the right-hand side of the right-most @@ in

an email address.

Per-destination logfiles of deferred mail are maintained only for eli-

gible destinations. The list of eligible destinations is specified with the ffaassttfflluusshhddoommaaiinnss configuration parameter, which defaults to

$$rreellaayyddoommaaiinnss.

This server implements the following requests: aadddd sitename queueid

Inform the fast flush server that the message with the specified

queue ID is queued for the specified destination. sseenndd sitename

Request delivery of mail that is queued for the specified desti-

nation. rreeffrreesshh

Refresh non-empty per-destination logfiles that were not read in

$$ffaassttfflluusshhrreeffrreesshhttiimmee hours, by simulating send requests (see

above) for the corresponding destinations.

Delete empty per-destination logfiles that were not updated in

$$ffaassttfflluusshhppuurrggeettiimmee days.

This request completes in the background.

ppuurrggee Do a rreeffrreesshh for all per-destination logfiles.

SSEECCUURRIITTYY

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. DIAGNOSTICS Problems and transactions are logged to ssyyssllooggdd(8).

BUGS

Fast flush logfiles are truncated only after a "send" request, not when

mail is actually delivered, and therefore can accumulate outdated or redundant data. In order to maintain sanity, "refresh" must be executed

periodically. This can be automated with a suitable wakeup timer set-

ting in the mmaasstteerr..ccff configuration file. Upon receipt of a request to deliver mail for an eligible destination, the fflluusshh server requests delivery of all messages that are listed in

that destination's logfile, regardless of the recipients of those mes-

sages. This is not an issue for mail that is sent to a rreellaayyddoommaaiinnss destination because such mail typically only has recipients in one domain. CCOONNFFIIGGUURRAATTIIOONN PPAARRAAMMEETTEERRSS

Changes to mmaaiinn..ccff are picked up automatically as flush(8) processes

run for only a limited amount of time. Use the command "ppoossttffiixx rreellooaadd" to speed up a change. The text below provides only a parameter summary. See postconf(5) for more details including examples.

ccoonnffiiggddiirreeccttoorryy ((sseeee ''ppoossttccoonnff -dd'' oouuttppuutt))

The default location of the Postfix main.cf and master.cf con-

figuration files. ddaaeemmoonnttiimmeeoouutt ((1188000000ss)) How much time a Postfix daemon process may take to handle a

request before it is terminated by a built-in watchdog timer.

ffaassttfflluusshhddoommaaiinnss (($$rreellaayyddoommaaiinnss))

Optional list of destinations that are eligible for per-destina-

tion logfiles with mail that is queued to those destinations. ffaassttfflluusshhrreeffrreesshhttiimmee ((1122hh))

The time after which a non-empty but unread per-destination

"fast flush" logfile needs to be refreshed.

ffaassttfflluusshhppuurrggeettiimmee ((77dd))

The time after which an empty per-destination "fast flush" log-

file is deleted. iippccttiimmeeoouutt ((33660000ss)) The time limit for sending or receiving information over an internal communication channel. mmaaxxiiddllee ((110000ss)) The maximum amount of time that an idle Postfix daemon process waits for the next service request before exiting. mmaaxxuussee ((110000))

The maximal number of connection requests before a Postfix dae-

mon process terminates.

ppaarreennttddoommaaiinnmmaattcchheessssuubbddoommaaiinnss ((sseeee ''ppoossttccoonnff -dd'' oouuttppuutt))

What Postfix features match subdomains of "domain.tld" automati-

cally, instead of requiring an explicit ".domain.tld" pattern.

pprroocceessssiidd ((rreeaadd-oonnllyy))

The process ID of a Postfix command or daemon process.

pprroocceessssnnaammee ((rreeaadd-oonnllyy))

The process name of a Postfix command or daemon process.

qquueeuueeddiirreeccttoorryy ((sseeee ''ppoossttccoonnff -dd'' oouuttppuutt))

The location of the Postfix top-level queue directory.

ssyyssllooggffaacciilliittyy ((mmaaiill)) The syslog facility of Postfix logging. ssyyssllooggnnaammee ((ppoossttffiixx)) The mail system name that is prepended to the process name in

syslog records, so that "smtpd" becomes, for example, "post-

fix/smtpd". FILES