Configure Continuous Crawl in SharePoint 2016

SharePoint 2013 introduced a new Search crawl type called “Continuous Crawls” to keep the search results as fresh as possible. If enabled, Continuous crawl automatically starts at predefined intervals – By default, the interval for continuous crawls is every 15 minutes.

How does continuous crawl work in SharePoint?

Continuous crawl crawls modified content such as content added, changed, or deleted since the last crawl. Moreover, an incremental crawl automatically runs every four hours for content sources that have continuous crawl enabled to re-crawl any items that repeatedly return errors, as continuous crawl does not process or retry items that return errors more than three times.

Continuous crawl vs. incremental crawl SharePoint 2016:

Incremental starts at a particular time and regularly repeats at a specified schedule. But continuous crawl automatically starts at 15-minute time intervals by default. Multiple continuous crawls can run simultaneously, whereas you cannot run multiple full crawls or incremental crawls for the same content source in parallel – you’ll have to wait until the existing one completes.

Enable continuous crawl in SharePoint 2016:

Continuous crawl is to be enabled per SharePoint content source. To enable Continuous Crawl, follow these steps:

1. Go to Central Administration >> Service Applications >>Open the Search Service Application
2. Click on the Content Sources link from the left navigation.
3. In the content source page, select the content source, such as “Local SharePoint Sites”.
4. You will get the Edit Content Source page. Scroll down and set the “Enable Continuous Crawls” option under the Crawl Schedule section.
5. Click on the OK button to save the changes.

That’s all! You are done with enabling Continuous Crawl. To turn on the continuous crawl for SharePoint 13 using PowerShell, refer to: How to Enable Continuous Crawl in SharePoint 2013 using PowerShell?

Disable continuous crawl SharePoint

To disable the continuous crawl,

1. Open Search service application >> From the target content source’s context menu, choose “Disable Continuous Crawl”.
2. Confirm the prompt to disable continuous crawl. This will disable the continuous crawl.
3. Once it’s disabled, SharePoint 2013 automatically triggers an incremental crawl.

SharePoint 2016 search continuous crawl performance: The Crawler Impact Rules control the maximum number of requests that can be executed by the server (By default, it’s 8). To disable continuous crawl using PowerShell, refer: Disable Continuous Crawl in SharePoint 2013 using PowerShell

Technet reference on Manage continuous crawls in SharePoint Server 2016: https://technet.microsoft.com/en-us/library/jj219802(v=office.16).aspx