trusty (3) Gearman::Worker.3pm.gz

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');
           $worker->register_function($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.

   $worker->job_servers(@servers)
       Initializes the worker $worker with the list of job servers in @servers.  @servers should contain a list
       of IP addresses, with optional port numbers.  For example:

           $worker->job_servers('127.0.0.1', '192.168.1.100:7003');

       If the port number is not provided, 7003 is used as the default.

       Calling this method will do nothing in a worker that is running as a child process of a gearman server.

   $worker->register_function($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.

   $client->prefix($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 concatentation of the prefix and the
       function name.

   Gearman::Job->arg
       Returns the scalar argument that the client sent to the job server.

   Gearman::Job->set_status($numerator, $denominator)
       Updates the status of the job (most likely, a long-running job) and sends it back to the job server.
       $numerator and $denominator should represent the percentage completion of the job.

   Gearman::Job->work(%opts)
       Do one job and returns (no value returned).  You can pass "on_start" "on_complete" and "on_fail"
       callbacks in %opts.

WORKERS AS CHILD PROCESSES

       Gearman workers can be run 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.

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.