Search Architecture in SharePoint 2013

Search architecture in SharePoint 2013 has undergone massive changes in comparison to the earlier versions of SharePoint. A primary change is, SharePoint 2013, fast search has been embedded in the native search engine as compared to previous version of SharePoint 2010, where fast search was a separate installation.

1. Search in SharePoint 2013 has been enhanced in several ways with enhancements for ‘types of users’. For example, for end-users, SharePoint 2013 search enables them find relevant information more quickly and easily. For developers and administrators, SharePoint 2013 search provides new APIs and customized search experience.
2. Also, Search in SharePoint 2013 has been re-architected to a single search platform. Search architecture in SharePoint 2013 has the following components:
   1. Crawl and content processing
   2. Index component
   3. Query processing components
   4. Analytics components
   5. Search administration component

Below is the search architecture diagram, which has different components as indicated above.

Let us discuss each of the components of SharePoint 2013 search engine architecture in detail.

1. Crawl Component: connects to different content sources using protocol handlers and crawls the content. Crawl engine crawls the contents and extracts the crawled properties and Metadata from the crawled content. Crawl component then passes it to the content processing component.
2. Crawl Database: is one of the key sections of the crawl and content processing component. Crawler will crawl the content and the extracted information will be stored in the crawl database. Crawl database stores the information about the timestamp of the crawled items, last crawled time, last crawl ID and the type of update during the last crawl.
3. Content Processing Component: Here, the information sent by the crawl component is processed and passed to the index component.
4. Link Database: The crawled link information extracted from the crawl component and proceeding link information from the content processing component is stored in the link database.
5. Index Component: gets the processed items from the content processing component and makes an entry about the processed items in the search index. Index component is also responsible for handling incoming queries form query processing component and gets the result form the search index and passes it to the query processing components.
6. Query Processing Component: This component in the SharePoint 2013 search engine is responsible for analyzing and processing search query. Processed query is sent to the index component which in turn submits the query to the search index and search index returns the result set.
7. Analytics Component: contains analytics processing component, link database, analytic reporting database and event store. Analytics processing component is responsible for usage analytics and search analytics. Link database in the analytics component stores search click information. Analytics database in this component stores the result of usage analytics. Event store captures the data for usage events that are captured at the front end.
8. Search administration: This component in SharePoint 2013 search engine, helps running in system processes. Using search administration component you can add new instances of search components. Search administration database in search administration component stores search configuration data.

Search Service Application:

Search engine in SharePoint 2013 is exposed using a service application known as search service application. Search service application provides you an interface to configure different components of the search architecture discussed in the above segment.

To create a search application follow the steps and screenshots given below.

1. Open the SharePoint Central Administration Site using an admin account.
2. Under Application Management section click on manage service application as shown in the screenshot below.
   
3. Click on new button on the service application page as shown in the screenshot below. Click on the search service application from the drop down.
   
4. Click event would open a dialog page to capture the configuration properties information. The settings you specify here can be changed later using the properties button in the manage service application page, after selecting the appropriate service application.

Fill in the necessary settings details and click ok.

After few minutes the search service application will be created and a web page as shown in below screenshot will be displayed.

Using the above shown search administration page, you can configure the search in your form.