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Алексей Пастухов > Gearman > Gearman::Worker

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Module Version: 2.004.010   Source  

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',
      {
        host      => '10.0.0.1',
        port      => 4730,
        socket_cb => sub {...},
        use_ssl   => 1,
        ca_file   => ...,
        cert_file => ...,
        key_file  => ...,
      }
    );

    $worker->register_function($funcname => $subref);

    $worker->work(
      stop_if => sub {
        my ($is_idle, $last_job_time) = @_;
        # stop idle worker
        return $is_idle;
      }
    );

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:

Gearman::Worker is derived from Gearman::Objects

$worker->prefix($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.

NOTE ^

If you intend using UTF-8 data with SSL based connection, beware there is no UTF-8 support in underlying Net::SSLeay. "Forcing-Unicode-in-Perl-(Or-Unforcing-Unicode-in-Perl)" in perlunicode describes proper workarounds.

METHODS ^

reset_abilities

tell all the jobservers that this worker can't do anything

return true if reset_abilityes request successfully transmitted to job_servers

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.

return true if $funcname registration successfully transmitted to job_servers

unregister_function($funcname)

send cant_do $funcname request to job_servers

return true if CANT_DO $funcname request successfully transmitted to job_servers

job_servers(@servers)

Override Gearman::Objects method to skip job server initialization if working with Gearman::Server.

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

send_work_complete($job, $v)

notify the server (and listening clients) that job completed successfully

send_work_data($job, $data)

Use this method to update the client with data from a running job.

send_work_warning($job, $message)

Use this method to send a warning $message to the server (and any listening clients) with regard to the running job.

send_work_exception($job, $exception)

Use this method to notify the server (and any listening clients) that the job failed with the given $exception.

If you are using Gearman::Client, you have to set parameter exceptions properly to get worker exception notifications.

send_work_fail($job)

Use this method to notify the server (and any listening clients) that the job failed.

send_work_status($job, $numerator, $denominator)

Use this method to send periodically to the server status update for long running jobs to update the percentage complete.

_uncache_sock($js, $reason)

close TCP connection

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 job_servers 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.

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