NAME
Gearman::Worker - Worker for gearman distributed job system
SYNOPSIS
use Gearman::Worker;
my $worker = Gearman::Worker->new;
$worker->job_servers(
'127.0.0.1',
{
ca_certs => ...,
cert_file => ...,
host => '10.0.0.1',
key_file => ...,
port => 4733,
socket_cb => sub {...},
use_ssl => 1,
}
);
$worker->register_function($funcname => $subref);
$worker->work while 1;DESCRIPTION
Gearman::Worker is a worker class for the Gearman distributed job system, providing a framework for receiving and serving jobs from a Gearman server.
Callers instantiate a Gearman::Worker object, register a list of functions and capabilities that they can handle, then enter an event loop, waiting for the server to send jobs.
The worker can send a return value back to the server, which then gets sent back to the client that requested the job; or it can simply execute silently.
USAGE
Gearman::Worker->new(%options)
Creates a new Gearman::Worker object, and returns the object.
If %options is provided, initializes the new worker object with the settings in %options, which can contain:
job_servers
Calls job_servers (see below) to initialize the list of job servers. It will be ignored if this worker is running as a child process of a gearman server.
prefix
Calls prefix (see below) to set the prefix / namespace.
$client->prefix($prefix)
Sets the namespace / prefix for the function names. This is useful for sharing job servers between different applications or different instances of the same application (different development sandboxes for example).
The namespace is currently implemented as a simple tab separated concatenation of the prefix and the function name.
EXAMPLES
Summation
This is an example worker that receives a request to sum up a list of integers.
use Gearman::Worker;
use Storable qw( thaw );
use List::Util qw( sum );
my $worker = Gearman::Worker->new;
$worker->job_servers('127.0.0.1');
$worker->register_function(sum => sub { sum @{ thaw($_[0]->arg) } });
$worker->work while 1;See the Gearman::Client documentation for a sample client sending the sum job.
METHODS
reset_abilities
tell all the jobservers that this worker can't do anything
uncache_sock($ipport, $reason)
close TCP connection
work(%opts)
Endless loop takes a job and wait for the next one. You can pass "stop_if", "on_start", "on_complete" and "on_fail" callbacks in %opts.
$worker->register_function($funcname, $subref)
$worker->register_function($funcname, $timeout, $subref)
Registers the function $funcname as being provided by the worker $worker, and advertises these capabilities to all of the job servers defined in this worker.
$subref must be a subroutine reference that will be invoked when the worker receives a request for this function. It will be passed a Gearman::Job object representing the job that has been received by the worker.
$timeout is an optional parameter specifying how long the jobserver will wait for your subroutine to give an answer. Exceeding this time will result in the jobserver reassigning the task and ignoring your result. This prevents a gimpy worker from ruining the 'user experience' in many situations.
The subroutine reference can return a return value, which will be sent back to the job server.
unregister_function($funcname)
job_servers(@servers)
override Gearman::Objects method to skip job server initialization if defined $ENV{GEARMAN_WORKER_USE_STDIO}
Calling this method will do nothing in a worker that is running as a child process of a gearman server.
WORKERS AS CHILD PROCESSES
Gearman workers can be run as child processes of a parent process which embeds Gearman::Server. When such a parent process fork/execs a worker, it sets the environment variable GEARMAN_WORKER_USE_STDIO to true before launching the worker. If this variable is set to true, then the jobservers function and option for new() are ignored and the unix socket bound to STDIN/OUT are used instead as the IO path to the gearman server.