How to Use Apache Solr with Drupal?

It’s crucial to have a good network connection for a seamless search experience, but it’s also important to have an excellent search application for better surfing.

And Solr is one of the search applications that are scalable, reliable, and offers distributed indexing, replication, and load-balanced querying with a centralized setup.

Apache Solr is the right choice if you need an extremely fast and simple search application.

So, in this blog, we’ll learn about Apache Solr and how to use it with Drupal.

What is Apache Solr?

Apache Solr is an open-source enterprise search server. It is a robust, scalable, and highly flexible search platform capable of indexing large amounts of textual data in real-time.

Solr is built on top of Lucene, the leading open-source enterprise search engine. Solr provides full-text searching, faceted navigation, and full-text search over XML documents. Apache Solr can be used to power websites and applications that require full-text search capabilities, such as online retail shopping sites, news sites, social networks, and many more!

Solr’s extensibility allows you to write custom components for your application, such as a taxonomy for structured data; a query parser for crawling structured data sources or performing full-text searches on unstructured content like emails; a cache implementation; or even a cluster management framework.

How Does Apache Solr Work?

Apache Solr is an enterprise-grade, open-source, scalable, Enterprise Search Platform as a Service (ESPaaS). It has been designed from the ground up to be highly reliable, highly available, and highly scalable. Companies of all sizes use solr to help them find what they are looking for quickly and easily.

Solr indexes documents and stores them in a distributed file system cluster. It can be configured to read documents from several file formats (e.g., JSON or XML), including those that might change over time (e.g., schema changes). Documents are then indexed for searching purposes using a query language called LuceneTM.

The Apache Solr project is one of the most popular open-source projects on GitHub, with over 600,000 stars, over 1800 forks, and over 500 contributors.

Solr’s architecture includes three main components:

Indexer: The indexer reads text files and indexes them into Lucene (the core search engine).

Search Server: The search server sends queries to the indexer, which returns results to the client application.

Query Processor: The query processor processes each query before returning results to the client application.

Solr’s Main Features Include:

Highly-Available Architecture:

Solr is designed to handle large query loads with minimal impact on search response times. It does this by distributing documents across multiple servers, replicating them across multiple machines, and then moving documents from server to server as they are updated or deleted. This design enables Solr to scale horizontally from a single machine to thousands of machines in production environments.

Flexible Schema Design:

The flexible schema design allows you to create your search application using only the fields you need without worrying about creating complex queries. This makes it easy for developers to plug into existing applications without rewriting their code or learning advanced query language syntaxes like SQL.

Content Analysis:

Solr can analyze content from different sources, including posts and pages from social media platforms such as Facebook or Twitter. The content analysis feature enables users to search for terms that are relevant to their business by analyzing their content and keywords in the text of their blog posts or pages on social media networks such as Facebook or Twitter.

Using Apache Solr with Drupal

Step 1.

Install Solr:
Solr can be installed on both Apache Tomcat and Apache SolrCloud. We recommend installing Solr on an Apache Tomcat instance since this is the most common type of installation used by applications such as Drupal.

Step 2.

Create a schema.xml file to define your Apache Solr data model:

Click on the Admin link in the top-right corner of your site’s index view page, then click on the link labeled “Tools” at the bottom of your screen. A new window should appear with two tabs: Administration and Configuration. Click on the Administration tab if it is not already open, then click on the link labeled “Configure Solr…” in the lower-left corner of your screen.

This will open another window with several options for configuring Solr in your environment. Enter a name for your Apache Solr instance and choose whether or not you want to enable automatic indexing of all incoming content (recommended). After choosing these options, click on the “Submit Changes” button at the bottom of this page to save your settings and return to default configuration settings if needed.

Step 3.

Define the fields in schema.xml and their types:

In this step, you’ll define the fields in your Drupal entities and their mapping to Apache Solr indexed fields.

Step 4.

Define the field mapping between Drupal entities and Apache Solr indexed fields:
In this step, you’ll define how each entity type maps to an Apache Solr indexed field. You can do this by adding a new mapping for each entity type or creating a single mapping for all entities of that type.

Step 5.

Configure Apache Solr to use your custom entity field mappings:

In the Admin UI, go to the Configuration > Indexing section.

Click the Advanced tab and then click the Add Custom Field Mapping button.

In the Add Custom Field Mapping window, select Choose an existing mapping from a file and type .xml as the file name in the text box. Click Save when you are done filling out this form.

Enter your file path in the File Path field and click Save when you are done filling out this form.

Once you have completed these steps, click Save & Restart to activate your new custom field mapping.

The Bottom Line

There are several good reasons to use Drupal Solr. While the abstraction layer requires a moderate amount of effort, and it can be a bit more difficult to troubleshoot issues, the benefits include better indexation and searching, plus faster site load times. In other words, Drupal and Solr work together to make your website more functional and search-friendly.

Still confused?? No worries!! LN Webworks is here to help you with a flawless Drupal experience, so talk to our Drupal specialists and get the information you need.