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Net::Server::PreForkSiUser(Contributed Perl DocumNet::Server::PreForkSimple(3)

NAME
       Net::Server::PreForkSimple - Net::Server	personality

SYNOPSIS
	   use base qw(Net::Server::PreForkSimple);

	   sub process_request {
	       #...code...
	   }

	   __PACKAGE__->run();

DESCRIPTION
       Please read the pod on Net::Server first.  This module is a
       personality, or extension, or sub class,	of the Net::Server module.

       This personality	binds to one or	more ports and then forks
       "max_servers" child processes.  The server will make sure that at any
       given time there	are always "max_servers" available to receive a	client
       request.	 Each of these children	will process up	to "max_requests"
       client connections.  This type is good for a heavily hit	site that can
       keep "max_servers" processes dedicated to the serving.  (Multi port
       accept defaults to using	flock to serialize the children).

       At this time, it	does not appear	that this module will pass tests on
       Win32 systems.  Any ideas or patches for	making the tests pass would be
       welcome.

SAMPLE CODE
       Please see the sample listed in Net::Server.

COMMAND	LINE ARGUMENTS
       In addition to the command line arguments of the	Net::Server base
       class, Net::Server::PreFork contains several other configurable
       parameters.

	   Key		     Value		     Default
	   max_servers	     \d+		     50
	   max_requests	     \d+		     1000

	   serialize	     (flock|semaphore
			      |pipe|none)  undef
	   # serialize defaults	to flock on multi_port or on Solaris
	   lock_file	     "filename"		     File::Temp->new

	   check_for_dead    \d+		     30

	   max_dequeue	     \d+		     undef
	   check_for_dequeue \d+		     undef

       max_servers
	   The maximum number of child servers to start	and maintain.  This
	   does	not apply to dequeue processes.

       max_requests
	   The number of client	connections to receive before a	child
	   terminates.

       serialize
	   Determines whether the server serializes child connections.
	   Options are undef, flock, semaphore,	pipe, or none.	Default	is
	   undef.  On multi_port servers or on servers running on Solaris, the
	   default is flock.  The flock	option uses blocking exclusive flock
	   on the file specified in lock_file (see below).  The	semaphore
	   option uses IPC::Semaphore (thanks to Bennett Todd) for giving some
	   sample code.	 The pipe option reads on a pipe to choose the next.
	   the flock option should be the most bulletproof while the pipe
	   option should be the	most portable.	(Flock is able to reliquish
	   the block if	the process dies between accept	on the socket and
	   reading of the client connection - semaphore	and pipe do not).  An
	   option of none will not perform any serialization.  If "none" is
	   passed and there are	multiple ports then a the default
	   serialization will be used insted of	"none."

       lock_file
	   Filename to use in flock serialized accept in order to serialize
	   the accept sequece between the children.  This will default to a
	   generated temporary filename.  If default value is used the
	   lock_file will be removed when the server closes.

       check_for_dead
	   Seconds to wait before checking to see if a child died without
	   letting the parent know.

       max_dequeue
	   The maximum number of dequeue processes to start.  If a value of
	   zero	or undef is given, no dequeue processes	will be	started.  The
	   number of running dequeue processes will be checked by the
	   check_for_dead variable.

       check_for_dequeue
	   Seconds to wait before forking off a	dequeue	process.  The
	   run_dequeue hook must be defined when using this setting.  It is
	   intended to use the dequeue process to take care of items such as
	   mail	queues.	 If a value of undef is	given, no dequeue processes
	   will	be started.

CONFIGURATION FILE
       "Net::Server::PreFork" allows for the use of a configuration file to
       read in server parameters.  The format of this conf file	is simple key
       value pairs.  Comments and white	space are ignored.

	   #-------------- file	test.conf --------------

	   ### server information
	   max_servers	 80

	   max_requests	 1000

	   ### user and	group to become
	   user	       somebody
	   group       everybody

	   ### logging ?
	   log_file    /var/log/server.log
	   log_level   3
	   pid_file    /tmp/server.pid

	   ### access control
	   allow       .+\.(net|com)
	   allow       domain\.com
	   deny	       a.+

	   ### background the process?
	   background  1

	   ### ports to	bind
	   host	       127.0.0.1
	   port	       localhost:20204
	   port	       20205

	   ### reverse lookups ?
	   # reverse_lookups on

	   #-------------- file	test.conf --------------

PROCESS	FLOW
       Process flow follows Net::Server	until the loop phase.  At this point
       "max_servers" are forked	and wait for connections.  When	a child
       accepts a connection, finishs processing	a client, or exits, it relays
       that information	to the parent, which keeps track and makes sure	there
       are always "max_servers"	running.

HOOKS
       The PreForkSimple server	has the	following hooks	in addition to the
       hooks provided by the Net::Server base class.  See Net::Server

       "$self->run_n_children_hook()"
	   This	hook occurs at the top of run_n_children which is called each
	   time	the server goes	to start more child processes.	This gives the
	   parent to do	a little of its	own accountting	(as desired).  Idea
	   for this hook came from James FitzGibbon.

       "$self->child_init_hook()"
	   This	hook takes place immeditately after the	child process forks
	   from	the parent and before the child	begins accepting connections.
	   It is intended for any addiotional chrooting	or other security
	   measures.  It is suggested that all perl modules be used by this
	   point, so that the most shared memory possible is used.

       "$self->child_finish_hook()"
	   This	hook takes place immediately before the	child tells the	parent
	   that	it is exiting.	It is intended for saving out logged
	   information or other	general	cleanup.

       "$self->run_dequeue()"
	   This	hook only gets called in conjunction with the
	   check_for_dequeue setting.

       "$self->idle_loop_hook()"
	   This	hook is	called in every	pass through the main process wait
	   loop.

HOT DEPLOY
       Since version 2.000, the	PreForkSimple server has accepted the TTIN and
       TTOU signals.  When a TTIN is received, the max_servers is increased by
       1.  If a	TTOU signal is received	the max_servers	is decreased by	1.
       This allows for adjusting the number of handling	processes without
       having to restart the server.

BUGS
       Tests don't seem	to work	on Win32.  Any ideas or	patches	would be
       welcome.

TO DO
       See Net::Server

AUTHOR
       Paul T. Seamons paul@seamons.com

THANKS
       See Net::Server

SEE ALSO
       Please see also Net::Server::Fork, Net::Server::INET,
       Net::Server::PreFork, Net::Server::MultiType, Net::Server::Single
       Net::Server::SIG	Net::Server::Daemonize Net::Server::Proto

perl v5.32.0			  2017-08-10	 Net::Server::PreForkSimple(3)

NAME | SYNOPSIS | DESCRIPTION | SAMPLE CODE | COMMAND LINE ARGUMENTS | CONFIGURATION FILE | PROCESS FLOW | HOOKS | HOT DEPLOY | BUGS | TO DO | AUTHOR | THANKS | SEE ALSO

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