Server::Starter(3) User Contributed Perl Documentation Server::Starter(3)NAMEServer::Starter - a superdaemon for hot-deploying server programs
SYNOPSIS
# from command line
% start_server --port=80 my_httpd
# in my_httpd
use Server::Starterqw(server_ports);
my $listen_sock = IO::Socket::INET->new(
Proto => 'tcp',
);
$listen_sock->fdopen((values %{server_ports()})[0], 'w')
or die "failed to bind to listening socket:$!";
while (1) {
if (my $conn = $listen_sock->accept) {
....
}
}
DESCRIPTION
It is often a pain to write a server program that supports graceful
restarts, with no resource leaks. Server::Starter solves the problem
by splitting the task into two. One is start_server, a script provided
as a part of the module, which works as a superdaemon that binds to
zero or more TCP ports or unix sockets, and repeatedly spawns the
server program that actually handles the necessary tasks (for example,
responding to incoming commenctions). The spawned server programs
under Server::Starter call accept(2) and handle the requests.
To gracefully restart the server program, send SIGHUP to the
superdaemon. The superdaemon spawns a new server program, and if (and
only if) it starts up successfully, sends SIGTERM to the old server
program.
By using Server::Starter it is much easier to write a hot-deployable
server. Following are the only requirements a server program to be run
under Server::Starter should conform to:
- receive file descriptors to listen to through an environment variable
- perform a graceful shutdown when receiving SIGTERM
A Net::Server personality that can be run under Server::Starter exists
under the name Net::Server::SS::PreFork.
METHODS
server_ports
Returns zero or more file descriptors on which the server program
should call accept(2) in a hashref. Each element of the hashref
is: (host:port|port|path_of_unix_socket) => file_descriptor.
start_server
Starts the superdaemon. Used by the "start_server" script.
AUTHOR
Kazuho Oku
SEE ALSO
Net::Server::SS::PreFork
LICENSE
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.2 2012-09-25 Server::Starter(3)
