oracular (3) Mojo::Server::Prefork.3pm.gz
NAME
Mojo::Server::Prefork - Pre-forking non-blocking I/O HTTP and WebSocket server
SYNOPSIS
use Mojo::Server::Prefork;
my $prefork = Mojo::Server::Prefork->new(listen => ['http://*:8080']);
$prefork->unsubscribe('request')->on(request => sub ($prefork, $tx) {
# Request
my $method = $tx->req->method;
my $path = $tx->req->url->path;
# Response
$tx->res->code(200);
$tx->res->headers->content_type('text/plain');
$tx->res->body("$method request for $path!");
# Resume transaction
$tx->resume;
});
$prefork->run;
DESCRIPTION
Mojo::Server::Prefork is a full featured, UNIX optimized, pre-forking non-blocking I/O HTTP and WebSocket
server, built around the very well tested and reliable Mojo::Server::Daemon, with IPv6, TLS, SNI, UNIX
domain socket, Comet (long polling), keep-alive and multiple event loop support. Note that the server
uses signals for process management, so you should avoid modifying signal handlers in your applications.
For better scalability (epoll, kqueue) and to provide non-blocking name resolution, SOCKS5 as well as TLS
support, the optional modules EV (4.32+), Net::DNS::Native (0.15+), IO::Socket::Socks (0.64+) and
IO::Socket::SSL (1.84+) will be used automatically if possible. Individual features can also be disabled
with the "MOJO_NO_NNR", "MOJO_NO_SOCKS" and "MOJO_NO_TLS" environment variables.
See "DEPLOYMENT" in Mojolicious::Guides::Cookbook for more.
MANAGER SIGNALS
The Mojo::Server::Prefork manager process can be controlled at runtime with the following signals.
INT, TERM
Shut down server immediately.
QUIT
Shut down server gracefully.
TTIN
Increase worker pool by one.
TTOU
Decrease worker pool by one.
WORKER SIGNALS
Mojo::Server::Prefork worker processes can be controlled at runtime with the following signals.
QUIT
Stop worker gracefully.
EVENTS
Mojo::Server::Prefork inherits all events from Mojo::Server::Daemon and can emit the following new ones.
finish
$prefork->on(finish => sub ($prefork, $graceful) {...});
Emitted when the server shuts down.
$prefork->on(finish => sub ($prefork, $graceful) {
say $graceful ? 'Graceful server shutdown' : 'Server shutdown';
});
heartbeat
$prefork->on(heartbeat => sub ($prefork, $pid) {...});
Emitted when a heartbeat message has been received from a worker.
$prefork->on(heartbeat => sub ($prefork, $pid) { say "Worker $pid has a heartbeat" });
reap
$prefork->on(reap => sub ($prefork, $pid) {...});
Emitted when a child process exited.
$prefork->on(reap => sub ($prefork, $pid) { say "Worker $pid stopped" });
spawn
$prefork->on(spawn => sub ($prefork, $pid) {...});
Emitted when a worker process is spawned.
$prefork->on(spawn => sub ($prefork, $pid) { say "Worker $pid started" });
wait
$prefork->on(wait => sub ($prefork) {...});
Emitted when the manager starts waiting for new heartbeat messages.
$prefork->on(wait => sub ($prefork) {
my $workers = $prefork->workers;
say "Waiting for heartbeat messages from $workers workers";
});
ATTRIBUTES
Mojo::Server::Prefork inherits all attributes from Mojo::Server::Daemon and implements the following new
ones.
accepts
my $accepts = $prefork->accepts;
$prefork = $prefork->accepts(100);
Maximum number of connections a worker is allowed to accept, before stopping gracefully and then getting
replaced with a newly started worker, passed along to "max_accepts" in Mojo::IOLoop, defaults to 10000.
Setting the value to 0 will allow workers to accept new connections indefinitely. Note that up to half of
this value can be subtracted randomly to improve load balancing, and to make sure that not all workers
restart at the same time.
cleanup
my $bool = $prefork->cleanup;
$prefork = $prefork->cleanup($bool);
Delete "pid_file" automatically once it is not needed anymore, defaults to a true value.
graceful_timeout
my $timeout = $prefork->graceful_timeout;
$prefork = $prefork->graceful_timeout(15);
Maximum amount of time in seconds stopping a worker gracefully may take before being forced, defaults to
120. Note that this value should usually be a little larger than the maximum amount of time you expect
any one request to take.
heartbeat_interval
my $interval = $prefork->heartbeat_interval;
$prefork = $prefork->heartbeat_interval(3);
Heartbeat interval in seconds, defaults to 5.
heartbeat_timeout
my $timeout = $prefork->heartbeat_timeout;
$prefork = $prefork->heartbeat_timeout(2);
Maximum amount of time in seconds before a worker without a heartbeat will be stopped gracefully,
defaults to 50. Note that this value should usually be a little larger than the maximum amount of time
you expect any one operation to block the event loop.
pid_file
my $file = $prefork->pid_file;
$prefork = $prefork->pid_file('/tmp/prefork.pid');
Full path of process id file, defaults to "prefork.pid" in a temporary directory.
spare
my $spare = $prefork->spare;
$prefork = $prefork->spare(4);
Temporarily spawn up to this number of additional workers if there is a need, defaults to 2. This allows
for new workers to be started while old ones are still shutting down gracefully, drastically reducing the
performance cost of worker restarts.
workers
my $workers = $prefork->workers;
$prefork = $prefork->workers(10);
Number of worker processes, defaults to 4. A good rule of thumb is two worker processes per CPU core for
applications that perform mostly non-blocking operations, blocking operations often require more and
benefit from decreasing concurrency with "max_clients" in Mojo::Server::Daemon (often as low as 1).
METHODS
Mojo::Server::Prefork inherits all methods from Mojo::Server::Daemon and implements the following new
ones.
check_pid
my $pid = $prefork->check_pid;
Get process id for running server from "pid_file" or delete it if server is not running.
say 'Server is not running' unless $prefork->check_pid;
ensure_pid_file
$prefork->ensure_pid_file($pid);
Ensure "pid_file" exists.
healthy
my $healthy = $prefork->healthy;
Number of currently active worker processes with a heartbeat.
run
$prefork->run;
Run server and wait for "MANAGER SIGNALS".
SEE ALSO
Mojolicious, Mojolicious::Guides, <https://mojolicious.org>.