‘Continuous Crawls’ make items appear faster in search results in SharePoint 2013

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What are continuous crawls?

Continuous crawls help to keep the search index and search results as fresh as possible. This is a new feature in SharePoint 2013.

Because of changes in how the index is created and stored, a document can appear in the index within seconds of going through the content processing component – you no longer have to wait for long index merges until it shows in results.

It also means you can get the latest changes even while a full crawl is starting, so you can see results before full crawl completes.

Note: It only works with SharePoint sites as content sources.

When should I use them?

You should use this feature for your search driven applications. Everytime when it matters that new results appear right after they have been created.

The new Newsfeed in My Sites and Team Sites uses search, for example:

Enabling continuous crawl has the following advantages:

  • The search results are very fresh, because the SharePoint content is crawled frequently to keep the search index up to date.
  • The search administrator does not have to monitor changing or seasonal demands for content freshness. Continuous crawls automatically adapt as necessary to the change rate of the SharePoint content.
This new feature is not so important, when you just use a document library to store and exchange documents. In this case the ‘old’ incremental crawl should be enough.

How do they work?

Continuous crawls run every 15 minutes by default. When running, the crawler gets changes from SharePoint sites and pushes them to the content processing component.

The document will get processed by the content processing component on the fly. No index has to be merged. Items appear in the search results right after they have been crawled.

How do I configure them?

Step 1 – Edit the content source settings for your SharePoint sites

 

Step 2 – Change the crawl schedules to “Enable Continuous Crawls”

 

Step 3 – Change the interval for the continues crawls (optional)

The interval of 15 minutes is the default value, but you can change is with the PowerShell cmdlet Set-SPEnterpriseSearchCrawlContentSource.

Performance considerations

For a medium Internet sites (FIS) topology (optimized for 3,400,000 items, processing 240 documents per second, and a usage pattern of 85 page views per second, which corresponds to 129 queries per second) Microsoft recommends that you enable continuous crawl with an interval of one minute, instead of the default interval of 15 minutes.

You can use Crawl health reports to monitor performance and react on performance issues:

  • Central Administration > Application Management > Manage service applications > Search service application > Diagnostics > Crawl Health Reports

Want to learn more?

Technet:

Sources:

2 Responses to “‘Continuous Crawls’ make items appear faster in search results in SharePoint 2013”

  1. Mike

    “The interval of 15 minutes is the default value, but you can change is with the PowerShell cmdlet Set-SPEnterpriseSearchCrawlContentSource.”

    I went through of this cmled. There is no special continues crawls timer command or at least I didn’t find it.

    So did I understand it right that when you have set continues crawls enabled you can change the time interval by actully changing the incremental crawl scheduling?

    Reply

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