cron_zencache_cleanup never executing!

[xberg]

Hi
Using Pro version 160103.
The _cron_zencache_cleanup never executes. I use Crontrol to monitor the wp_cron and there's very strange behavior: The "next run" time keeps changing!!! I have it set to run every 3 hours, but the next run time is always in just 1 minute time! When I refresh the crontrol page I see your CRON is still schedule to run in a minute. and it NEVER NEVER runs. So this just fills my cache and I have several times a day to manually delete the cache!
Same bahavior with _cron_zencache_auto_cache but I don't use this.

I tried deleting and reinstalling: same problem.

And you CRONs are the ONLY ones I cannot delete or edit with crontrol. It's like your system is continusouly deleting and recreating new ones!

Please help me fix this ASAP.

[xberg]

I do NOT have the Disable Cache Expiration If Server Load Average is High enabled, but it seems to behave like it is and that my server is high.

[raamdev]

@xberg I'm not able to reproduce this behavior. The cronjobs are behaving as expected for me:

40 seconds before running

While running

Just after running

---

I suggest disabling deletion safeguards (ZenCache → Plugin Options → Plugin Deletion Safeguards) and then deactivating and deleting the ZenCache plugin. Then install it fresh and see if you still have issues.

(Note that if you have a custom plugin configuration that you want to backup, you can use ZenCache → Plugin Options → Import/Export Options.)

Also, it's normal for ZenCache to recreate the cron events if you delete them. ZenCache needs those events to be present for the plugin to work properly, so if ZenCache is active and it detects the events are missing, it will recreate them. If you don't want ZenCache to recreate the events, simply deactivate the plugin.

[raamdev]

@xberg Also, if you want to change the schedule at which the cache cleanup occurs, you can create a custom schedule with WP Crontrol (Dashboard → Settings → Cron Schedules) and then select that custom schedule in ZenCache → Plugin Options → Cache Expiration Time → Cache Cleanup Schedule:

[xberg]

Raam,
Just because you cannot reproduce the issue does not mean that the issue is not there.
I am experienced with CRON jobs and I can tell you that there is a major problem on my setup with just your plugin, and this only started a few weeks ago (at least 2 releases ago).
Yes, I can change the schedule to whatever I want, but your cleanup NEVER runs. It keeps reseting itself to run in a minute (but NEVER runs).

Let's try to find a temporary workaround: is there any code I could run thru a PHP to replicate the behavior of the cleanup? ie, I would be creating my own CRON?

Because I am using a 2 GB RAMDRIVE it fills in less than a day and then starts producing a massive number of errors. As such your plugin in unusable now.

[xberg]

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Here I am refreshing CRONTROL every 20 seconds. You can see that your CRONs are alway reset to run in 1 minute. In the meanwhile you can see that another cron, the NXS decrements correctly.

You have a problem and you need to acknowledge it.

[raamdev]

@xberg Have you reproduced this issue in a clean WordPress installation? See Testing ZenCache in a Clean WordPress Installation

If you have, then please provide me with a list of steps to reproduce this issue on my site.

[xberg]

Raamdev,

Do you have anything in your program that resets the counter to 1 minute? It would not surprise me at all that your "Disable Cache Expiration If Server Load Average is High" is creating the problem.

Otherwise is there any instruction I could run to replicate the behavior of your CRON?

Without this, what is your reimbursement policy as I can no longer use your caching with this bug.

[xberg]

Ah!! I found your code that was creating the bug. I cannot believe you did not immediately find it yourself after my description!

It's code you added 20151220 which resets the CRON to run in a minute: exactly the description I made initially!!!

It's in CronUtils.php and here it is:

/*

• Checks Cron setup, validates schedules, and reschedules events if necessary.
  *

• @attaches-to init hook.
  *

• @SInCE 151220 Improving WP Cron setup and validation of schedules
  /
  $self->checkCronSetup = function () use ($self) {
  if ($self->options['crons_setup'] < 1439005906
  || $self->options['crons_setup_on_namespace'] !== NAMESPACE
  || $self->options['crons_setup_with_cache_cleanup_schedule'] !== $self->options['cache_cleanup_schedule']
  || $self->options['crons_setup_on_wp_with_schedules'] !== sha1(serialize(wp_get_schedules()))
  || !wp_next_scheduled('cron'.GLOBAL_NS.'cleanup')
  /[pro strip-from="lite"]/ // Auto-cache engine.
  || !wp_next_scheduled('cron'.GLOBAL_NS.'auto_cache')
  /[/pro]*/
  ) {

  wp_clear_scheduled_hook('_cron_'.GLOBAL_NS.'_cleanup');
  wp_schedule_event(time() + 60, $self->options['cache_cleanup_schedule'], '_cron_'.GLOBAL_NS.'_cleanup');
  
  /*[pro strip-from="lite"]*/ // Auto-cache engine.
  wp_clear_scheduled_hook('_cron_'.GLOBAL_NS.'_auto_cache');
  wp_schedule_event(time() + 60, 'every15m', '_cron_'.GLOBAL_NS.'_auto_cache');
  /*[/pro]*/
  
  $self->updateOptions(
    array(
      'crons_setup'                             => time(),
      'crons_setup_on_namespace'                => __NAMESPACE__,
      'crons_setup_with_cache_cleanup_schedule' => $self->options['cache_cleanup_schedule'],
      'crons_setup_on_wp_with_schedules'        => sha1(serialize(wp_get_schedules()))
    )
  );
  

  }
  };

/*

• Resets crons_setup and clears WP-Cron schedules.
  *
• @SInCE 151220 Fixing bug with Auto-Cache Engine cron disappearing in some scenarios
  *
• @note This MUST happen upon uninstall and deactivation due to buggy WP_Cron behavior. Events with a custom schedule will disappear when plugin is not active (see http://bit.ly/1lGdr78).
  /
  $self->resetCronSetup = function ( ) use ($self) {
  if (is_multisite()) { // Main site CRON jobs.
  switch_to_blog(get_current_site()->blog_id);
  /[pro strip-from="lite"]/ // Auto-cache engine.
  wp_clear_scheduled_hook('cron'.GLOBAL_NS.'auto_cache');
  /[/pro]/
  wp_clear_scheduled_hook('cron'.GLOBAL_NS.'cleanup');
  restore_current_blog(); // Restore current blog.
  } else { // Standard WP installation.
  /[pro strip-from="lite"]_/ // Auto-cache engine.
  wp_clear_scheduled_hook('cron'.GLOBAL_NS.'auto_cache');
  /[/pro]*/
  wp_clear_scheduled_hook('cron'.GLOBAL_NS.'_cleanup');
  }
  $self->updateOptions(
  array( // Reset so that crons are rescheduled upon next activation
  'crons_setup' => $self->default_options['crons_setup'],
  'crons_setup_on_namespace' => $self->default_options['crons_setup_on_namespace'],
  'crons_setup_with_cache_cleanup_schedule' => $self->default_options['crons_setup_with_cache_cleanup_schedule'],
  'crons_setup_on_wp_with_schedules' => $self->default_options['crons_setup_on_wp_with_schedules']
  )
  );
  };

[xberg]

Remving this line fixed your bug:

|| $self->options['crons_setup_on_wp_with_schedules'] !== sha1(serialize(wp_get_schedules()))

[jaswrks]

@xberg Watch it with the tone! Show some respect here, and we will do the same.

I cannot believe you did not immediately find it yourself after my description!

Please cleanup the code that you posted and I will review as well. So far it looks like you solved the problem, but I'm not clear on why you're calling this a 🐛 yet. Please explain in greater details and we can work together at solving it.

[xberg]

Youi're right: I'm sorry about the tone.

[raamdev]

@xberg writes...

$self->options['crons_setup_on_wp_with_schedules'] !== sha1(serialize(wp_get_schedules()))`

The only reason that line would cause problems is if wp_get_schedules() changes on every page load (and that should never happen, which again, is why I asked you to reproduce this in a clean installation of WordPress to rule out issues with other plugins or custom code).

That line basically says, "if there has been a change to the WordPress Cron Schedules (i.e., you added/removed/changed a cron schedule), then set up the ZenCache cron events again". This is necessary because if you changed or delete a cron schedule that ZenCache was using, ZenCache must reconfigure its own cron events to make sure that it keeps working as expected.

I'm not seeing any bug in that code. I have tested it and it is working as expected.

[xberg]

Raamdev,
I am not a developer so I cannot help you. I just know that removing this line fixed my problem. With the line there was a continuous loop which kept creating a new cron job that was to execute in a minute, but immediately got deleted and recreated.

I understand it's hard to debug without being able to replicate, but I am convinced I am not the only one who will have this problem so at least now you know what has helped me fix things. The only reason I noticed this problem is that I am using a 2 GB Ramdrive for zencache and this filled up fast. If I were using harddrive it could have been weeks before I noticed a problem. And I also have crontrol installed which allowed me to see this problem: most users will not have crontrol.