Changing to ElggBatch will not make the process consume less CPU it'll go as fast as it can thus using all CPU.

If you want it to slow down build in a sleep(). Bu then it'll take longer.

Also with ElggBatch make sure 'limit' is set to false.

Also if your calling your cron job with curl you'll get the overhead of the webserver. Just make a script which does this part

// start Elgg (in pseudo code)
- Load the Composer autoloader
- start the Elgg Application

// start removing your entities
$options = [
    'type' => 'object', 
    'subtype' => 'subtype_needed_to_be_deleted', 
    'limit' => false,
    'batch' => true,
    'batch_inc_offset' => false,
];

$entities = elgg_get_entities($options);

foreach ($entities as $entity) {
   echo "Removing GUID: {$entity->guid}" . PHP_EOL;
   ...deletion process---
}

The foreach loop will go on until all entities have been removed

Thanks Jerome! I will try your recommendation and let you know how it goes.

With your approach, the CPU usage is mostly below 50% for MySQL service. Awesome!!

Thanks again Jerome!

Open PR

PR is merged, so in the next release of Elgg this will be fixed

Guys, thank you so much!

For path changes in DB
---------------------------
TABLE elgg_datalists
path
dataroot
TABLE  elgg_sites_entity

On Elgg 2 or newer the elgg_get_root_path() doesn't return the root path in all cases anymore. SInce Elgg 2 Elgg can be installed with composer (when not using the zip to install). The composer install would allow to install Elgg in a different path in relation to the install directory path. And therefore the path returned by elgg_get_root_path() seems a bit unreliable. I never needed to make use of this function (and also wasn't aware of the different behavior of this function on Elgg 1 or Elgg 2+). Are you sure you need this function, i.e. do you really need the install root folder? If you need another folder (e.g. something inside the mod folder) there are other function returning the path of these folders. Tell us you use case and then we might be able to suggest a better suited function.

I have resolved the issue. Thanks