Search engines are a critical component of your Liferay Portal installation. They allow you to provide documents in an index that can quickly be searched, rather than relying on expensive database queries. For more fundamental material on search and indexing in Liferay Portal, read here. If you’re here, you probably know the basics already and want to get started on configuring a search engine for your Liferay Portal deployment.
Liferay Portal ships with Elasticsearch, a highly scalable, full-text search engine. Elasticsearch is well supported and will almost certainly meet any search and indexing need you have. For deployment settings, learn to configure a standalone, or remote, Elasticsearch server or cluster here.
If you need to use Solr, it’s also supported in Liferay Portal, and you can read more about its configuration here.