NAME¶
TheSchwartz::Job - jobs for the reliable job queue
SYNOPSIS¶
my $client = TheSchwartz->new( databases => $DATABASE_INFO );
my $job = TheSchwartz::Job->new_from_array('MyWorker', foo => 'bar');
$client->dispatch_async($job);
$job = TheSchwartz::Job->new(
funcname => 'MyWorker',
uniqkey => 7,
arg => [ foo => 'bar' ],
);
$client->dispatch_async($job);
DESCRIPTION¶
"TheSchwartz::Job" models the jobs that are posted to the job queue by
your application, then grabbed and performed by your worker processes.
"TheSchwartz::Job" is a "Data::ObjectDriver" model class.
See Data::ObjectDriver::BaseObject.
FIELDS¶
"TheSchwartz::Job" objects have these possible fields:
"jobid"¶
The unique numeric identifier for this job. Set automatically when saved.
"funcid"¶
The numeric identifier for the type of job to perform. "TheSchwartz"
clients map function names (also known as abilities and worker class names) to
these numbers using "TheSchwartz::FuncMap" records.
"arg"¶
Arbitrary state data to supply to the worker process for this job. If specified
as a reference, the data is frozen to a blob with the "Storable"
module.
"uniqkey"¶
An arbitrary string identifier used to prevent applications from posting
duplicate jobs. At most one with the same "uniqkey" value can be
posted to a single "TheSchwartz" database.
"insert_time"¶
The "insert_time" field is not used.
"run_after"¶
The UNIX system time after which the job can next be attempted by a worker
process. This timestamp is set when a job is first created or is released
after a failure.
"grabbed_until"¶
The UNIX system time after which the job can next be available by a worker
process. This timestamp is set when a job is grabbed by a worker process, and
reset to 0 when is released due to failure to complete the job.
"priority"¶
The "priority" field is not used.
"coalesce"¶
A string used to discover jobs that can be efficiently pipelined with a given
job due to some shared resource. For example, for email delivery jobs, the
domain of an email address could be used as the "coalesce" value. A
worker process could then deliver all the mail queued for a given mail host
after connecting to it once.
USAGE¶
"TheSchwartz::Job->new( %args )"¶
Returns a new job object with the given data. Members of %args can be keyed on
any of the fields described above, or "funcname".
"TheSchwartz::Job->new_from_array( $funcname, $arg )"¶
Returns a new job with the given function name (also called
ability or
worker class), and the scalar or reference $arg for an argument.
"$job->funcname([ $funcname ])"¶
Returns the function name for the given job, after setting it to $funcname, if
specified.
"$job->handle([ $handle ])"¶
Returns the "TheSchwartz::JobHandle" object describing this job, after
setting it to $handle, if specified. A
job handle is a convenience
class for accessing other records related to jobs; as its convenience methods
are also available directly from "TheSchwartz::Job" instances, you
will usually not need to work directly with job handles.
"$job->driver()"¶
Returns the "Data::ObjectDriver" object driver for accessing the
database in which $job is stored. See Data::ObjectDriver.
"$job->add_failure( $msg )"¶
Records and returns a new "TheSchwartz::Error" object representing a
failure to perform $job, for reason $msg.
"$job->exit_status()"¶
Returns the
exit status specified by the worker that either completed the
job or declared it failed permanently. The exit status for a job will be
available for a period of time after the job has exited the queue. That time
is defined in the job's worker class's "keep_exit_status_for()"
method.
"$job->failure_log()"¶
Returns a list of the error messages specified to "add_failure()" when
a worker failed to perform the given job.
"$job->failures()"¶
Returns the number of times a worker has grabbed this job, only to fail to
complete it.
"$job->set_exit_status( $status )"¶
Records the exit status of the given job as $status.
"$job->did_something([ $value ])"¶
Returns whether the given job has been completed or failed since it was created
or loaded, setting whether it has to $value first, if specified.
"$job->debug( $msg )"¶
Sends the given message to the job's "TheSchwartz" client as debug
output.
"$job->set_as_current()"¶
Set $job as the current job being performed by its associated
"TheSchwartz" client.
WORKING¶
"TheSchwartz::Worker" classes should use these methods to update the
status of their jobs:
"$job->completed()"¶
Records that the given job has been fully performed and removes it from the job
queue. Completing a job records its exit status as 0.
"$job->failed( $msg, $exit_status )"¶
Records that the worker performing this job failed to complete it, for reason
$msg.
If workers have not failed to complete the job more times than the maximum
number of retries for that type of job, the job will be reattempted after its
retry delay has elapsed. The maximum number of retries and the delay before a
retry are defined in the job's worker class definition as
"max_retries()" and "retry_delay()" respectively.
If workers
have exceeded the maximum number of reattempts for this job,
the job's exit status is recorded as $exit_status, and the job is removed from
the queue. If $exit_status is not defined or 0, the job will be recorded with
an exit status of 1, to indicate a failure.
"$job->permanent_failure( $msg, $exit_status )"¶
Records that the worker performing this job failed to complete it, as in
"failed()", but that the job should
not be reattempted, no
matter how many times the job has been attempted before. The job's exit status
is thus recorded as $exit_status (or 1), and the job is removed from the
queue.
"$job->replace_with( @jobs )"¶
Atomically replaces the single job $job with the given set of jobs.
This can be used to decompose one "metajob" posted by your application
into a set of jobs workers can perform, or to post a job or jobs required to
complete the process already partly performed.
SEE ALSO¶
Data::ObjectDriver, Data::ObjectDriver::BaseObject, Storable