If you want to force run a partial reindex process, also called mview or materialized view to update only entries collected in a change log table

To programmatically mark on of the indexes as invalid you need help of

If you want to restore canceled order, rollback order cancellation and undo order cancel action in Magento and Magento 2 use the following SQL query...

redis-cli -h <host> -p <port> flushall

$obj = \Magento\Framework\App\ObjectManager::getInstance();...