PHP scheduling a task on webhosting without SSH/Console

问题

I have a php website that has a script that executes an update for my database with data from an external API. The script itself works perfectly fine but i need to time it so that it executes it every monday at 2:30 AM. I am using a webhosting where SSH is not available neither is any form of command execution such as exec() or passthru(). I've also looked at CRON jobs but i can't use that either because i have no access to a console.

An other option i found was using threads with phthreads. But it seemed that i need an extra libary (PECL) to use it, but again because i can't use any console i can't install that dependency.

So another solution i came up with myself is the idea of stealing a request of the first user that visits the website. I know it's not a beautiful solution that's why i want to ask if there are some other options for me where i can schedule a task. Or is stealing the request the only option here? Or did i make a mistake in my assumptions?

Also a VPS is no option for me.

Sorry for my bad english, it's not my native language.

回答1:

One way to do it is to let your visitors trigger the update.

The advantage to this is you are not exposing your updating script to the world.
The disadvantage is that your database will not be updated until the visit of your first user after 2:30 am on Mondays, and that first user will have to wait for the database to be updated.

Add this to your script:

/**
 * Checks if the database's last update was before 
 * Monday at 02:30
 *
 * @param \DateTime Time of last update.  Must be converted to DateTime object
 * @return boolean
 */
function databaseIsOutOfDate(DateTime $createDate) {

  // find the last Monday at 2:30 am.
  $monday = (new DateTime())->modify('tomorrow')->modify('previous monday')->format('Y-m-d 02:30:00');
  $lastUpdated = $createDate->format('Y-m-d H:i:s');

  return ($lastUpdated < $monday);
}

$date_time_from_database = '2019-05-27 02:30:00'; // this date value comes from your database
$last_updated = new DateTime($date_time_from_database);  

if(databaseIsOutOfDate($last_updated)) {
  print "Updating database, please try again later";
  // trigger your update script
  die; // if you continue, you'll have race condition.
}

print "continue with script";

来源：https://stackoverflow.com/questions/56328209/php-scheduling-a-task-on-webhosting-without-ssh-console

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php

server

pthreads

schedule