Manual Pages for UNIX Darwin command on man scache

SCACHE(8) SCACHE(8)

NAME

scache - Postfix shared connection cache server

SYNOPSIS

ssccaacchhee [generic Postfix daemon options]

DESCRIPTION

The ssccaacchhee(8) server maintains a shared multi-connection cache. This

information can be used by, for example, Postfix SMTP clients or other Postfix delivery agents.

The connection cache is organized into logical destination names, phys-

ical endpoint names, and connections. As a specific example, logical SMTP destinations specify (transport, domain, port), and physical SMTP endpoints specify (transport, IP address, port). An SMTP connection may be saved after a successful mail transaction. In the general case, one logical destination may refer to zero or more physical endpoints, one physical endpoint may be referenced by zero or more logical destinations, and one endpoint may refer to zero or more connections.

The exact syntax of a logical destination or endpoint name is applica-

tion dependent; the ssccaacchhee(8) server does not care. A connection is

stored as a file descriptor together with application-dependent infor-

mation that is needed to re-activate a connection object. Again, the

ssccaacchhee(8) server is completely unaware of the details of that informa-

tion.

All information is stored with a finite time to live (ttl). The con-

nection cache daemon terminates when no client is connected for mmaaxxiiddllee time units. This server implements the following requests: ssaavveeeennddpp ttl endpoint endpointproperties filedescriptor Save the specified file descriptor and connection property data under the specified endpoint name. The endpoint properties are

used by the client to re-activate a passivated connection

object. ffiinnddeennddpp endpoint Look up cached properties and a cached file descriptor for the specified endpoint. ssaavveeddeesstt ttl destination destinationproperties endpoint Save the binding between a logical destination and an endpoint under the destination name, together with destination specific connection properties. The destination properties are used by

the client to re-activate a passivated connection object.

ffiinnddddeesstt destination

Look up cached destination properties, cached endpoint proper-

ties, and a cached file descriptor for the specified logical destination. SSEECCUURRIITTYY

The ssccaacchhee(8) server is not security-sensitive. It does not talk to the

network, and it does not talk to local users. The ssccaacchhee(8) server can run chrooted at fixed low privilege. The ssccaacchhee(8) server is not a trusted process. It must not be used to store information that is security sensitive. DIAGNOSTICS Problems and transactions are logged to ssyyssllooggdd(8).

BUGS

The session cache cannot be shared among multiple machines. When a connection expires from the cache, it is closed without the appropriate protocol specific handshake. CCOONNFFIIGGUURRAATTIIOONN PPAARRAAMMEETTEERRSS Changes to mmaaiinn..ccff are picked up automatically as ssccaacchhee(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 ppoossttccoonnff(5) for more details including examples. RREESSOOUURRCCEE CCOONNTTRROOLLSS ccoonnnneeccttiioonnccaacchheettttlllliimmiitt ((22ss))

The maximal time-to-live value that the ssccaacchhee(8) connection

cache server allows. ccoonnnneeccttiioonnccaacchheessttaattuussuuppddaatteettiimmee ((660000ss)) How frequently the ssccaacchhee(8) server logs usage statistics with connection cache hit and miss rates for logical destinations and for physical endpoints. MMIISSCCEELLLLAANNEEOOUUSS CCOONNTTRROOLLSS

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.

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 an incoming connection before terminating voluntarily.

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. 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".