Magento_Indexer module is a base of Magento Indexing functionality. It allows:
- read indexers configuration,
- represent indexers in admin,
- regenerate indexes by cron schedule,
- regenerate indexes from console,
- view and reset indexer state from console,
- view and set indexer mode from console
There are 2 modes of the Indexers: “Update on save” and “Update by schedule”.
Manual full reindex can be performed via console by running
php -f bin/magento indexer:reindex console command.