Retry Policies

Implements a custom RetryPolicy

The library contains RetryPolicies that cover the most common cases.

If needed, we can create a new policy to cover our specific needs.

To create a new policy, we need to create a class that implements the Recruiter\RetryPolicy interface

DoNotDoItAgain

This is the default (implicit) RetryPolicy, use it only if you want to make explicit the fact that the job should not be repeated.

<?php

use Recruiter\Recruiter;
use Recruiter\Workable\ShellCommand;
use Recruiter\RetryPolicy\DoNotDoItAgain;

$mongodbInstance = new MongoDB\Client(...);
$recruiter = new Recruiter($mongodbInstance);

ShellCommand::fromCommandLine("false");
   ->asJobOf($recruiter)
   ->retryWithPolicy(new DoNotDoItAgain())
   ->inBackground()
   ->execute()
;

ExponentialBackoff

This RetryPolicy allows you to retry job execution at exponential intervals. For example, we can set a maximum of 10 retries with an initial interval of 30 seconds. This means that after the first failure, a retry will be attempted after 30 seconds, if this also fails another retry will be attempted after 60 seconds, if this also fails a new retry will be attempted after 120 seconds and so on, up to a maximum of 10 new attempts.

The ExponentialBackoff policy accepts as parameters the maximum number of attempts to make and the initial seconds of interval before making the first attempt.

Examples:

<?php

use Recruiter\Recruiter;
use Recruiter\Workable\ShellCommand;
use Recruiter\RetryPolicy\ExponentialBackoff;

$mongodbInstance = new MongoDB\Client(...);
$recruiter = new Recruiter($mongodbInstance);

$retryPolicy = ExponentialBackoff::forTimes(10, 30);
//This is the same to the following:
// $retryPolicy = new ExponentialBackoff(10, 30);

ShellCommand::fromCommandLine("false");
   ->asJobOf($recruiter)
   ->retryWithPolicy($retryPolicy)
   ->inBackground()
   ->execute()
;

..TODO: verify the following part before publishing it .. This policy also includes a factory method that accepts the maximum number of seconds to retry and the initial number of seconds of interval before making the first attempt: .. .. Examples: .. .. .. code-block:: php .. .. <?php .. .. use RecruiterRecruiter; .. use RecruiterWorkableShellCommand; .. use RecruiterRetryPolicyExponentialBackoff; .. .. $mongodbInstance = new MongoDBClient(…); .. $recruiter = new Recruiter($mongodbInstance); .. .. // In this case there will be a maximum of 4 attempts: after the first failure a retry will be made after 30 seconds, another one after 60 seconds, and the last after 120 seconds .. $retryPolicy = ExponentialBackoff::forAnInterval(120, 30); .. .. ShellCommand::fromCommandLine(“false”); .. ->asJobOf($recruiter) .. ->retryWithPolicy($retryPolicy) .. ->scheduleAt(Moment::fromDateTime(new DateTime(‘2027-02-21T15:00:00.0000Z’);)) .. ->inBackground() .. ->execute() .. ;

RetryForevers

This RetryPolicy allows you to retry job execution infinitely by specifying the time interval between one attempt and another. If for example we wanted to run a job infinitely waiting 30 seconds between one attempt and another, we can write:

<?php

use Recruiter\Recruiter;
use Recruiter\Workable\ShellCommand;
use Recruiter\RetryPolicy\RetryForevers;

$mongodbInstance = new MongoDB\Client(...);
$recruiter = new Recruiter($mongodbInstance);

$retryPolicy = RetryForevers::afterSeconds(30);
//This is the same to the following:
// $retryPolicy = new RetryForevers(30);

ShellCommand::fromCommandLine("false");
   ->asJobOf($recruiter)
   ->retryWithPolicy($retryPolicy)
   ->inBackground()
   ->execute()
;

RetryManyTimes

This RetryPolicy allows you to retry job execution a finite number of times by specifying the time interval between one attempt and another. If for example we want to retry a job 3 times, waiting 30 seconds between one attempt and another, we can write:

<?php

use Recruiter\Recruiter;
use Recruiter\Workable\ShellCommand;
use Recruiter\RetryPolicy\RetryManyTimes;

$mongodbInstance = new MongoDB\Client(...);
$recruiter = new Recruiter($mongodbInstance);

$retryPolicy = RetryManyTimes::forTimes(3, 30);
//This is the same to the following:
// $retryPolicy = new RetryManyTimes(3, 30);

ShellCommand::fromCommandLine("false");
   ->asJobOf($recruiter)
   ->retryWithPolicy($retryPolicy)
   ->inBackground()
   ->execute()
;

TimeTable

This RetryPolicy allows you to retry job execution at regular intervals depending on how much time has passed since the job was created.

For example, if we wanted to retry the job * every minute for the first 5 minutes of the job’s life, * every 5 minutes for the first hour (i.e., the next 55 minutes) .. * every 5 minutes for the next 55 minutes * and every hour for the first 24 hours (i.e., the next 23 hours) .. * every hour for the next 23 hours

We can write the following code:

<?php

use Recruiter\Recruiter;
use Recruiter\Workable\ShellCommand;
use Recruiter\RetryPolicy\TimeTable;

$mongodbInstance = new MongoDB\Client(...);
$recruiter = new Recruiter($mongodbInstance);

$retryPolicy = new TimeTable([
   '5 minutes ago' => '1 minute',
   '1 hour ago' => '5 minutes',
   '24 hours ago' => '1 hour',
]);

ShellCommand::fromCommandLine("false");
   ->asJobOf($recruiter)
   ->retryWithPolicy($retryPolicy)
   ->inBackground()
   ->execute()
;

Warning

This policy accepts a key-value array where both keys and values must be strings parsable by the php strtotime function