What does the «Use Separate Process» option mean in the «Cron (Scheduled Tasks)» settings block?

dmitry_fedyuk · June 24, 2017, 4:21pm

magento/magento2/blob/2.2.0-RC1.1/app/code/Magento/Cron/etc/adminhtml/system.xml#L34-L37


<field id="use_separate_process" translate="label" type="select" sortOrder="70" showInDefault="1" showInWebsite="0" showInStore="0" canRestore="1">
    <label>Use Separate Process</label>
    <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
</field>

Magento\Cron\Observer\ProcessCronQueueObserver::execute()

github.com

magento/magento2/blob/2.2.0-RC1.1/app/code/Magento/Cron/Observer/ProcessCronQueueObserver.php#L188-L212


foreach ($jobGroupsRoot as $groupId => $jobsRoot) {
    $this->_cleanup($groupId);
    $this->_generate($groupId);
    if ($this->_request->getParam('group') !== null
        && $this->_request->getParam('group') !== '\'' . ($groupId) . '\''
        && $this->_request->getParam('group') !== $groupId
    ) {
        continue;
    }
    if (($this->_request->getParam(self::STANDALONE_PROCESS_STARTED) !== '1') && (
            $this->_scopeConfig->getValue(
                'system/cron/' . $groupId . '/use_separate_process',
                \Magento\Store\Model\ScopeInterface::SCOPE_STORE
            ) == 1
        )
    ) {
        $this->_shell->execute(
            $phpPath . ' %s cron:run --group=' . $groupId . ' --' . Cli::INPUT_KEY_BOOTSTRAP . '='
            . self::STANDALONE_PROCESS_STARTED . '=1',
            [
                BP . '/bin/magento'
            ]
        );
        continue;
    }

dmitry_fedyuk · June 24, 2017, 4:35pm

Conclusion

If the «Use Separate Process» option is enabled for a Cron group, then the group’s jobs will be executed in a separate process of the operating system.
Usually, Magento 2 contains only 2 Cron groups: default and index, but third-party extensions can add extra Cron groups.

dmitry_fedyuk · October 13, 2019, 7:56pm

How to prevent the primary PHP process from forking on bin/magento cron:run?