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25Jul/141

Article – Enabling Continuous Crawling in SharePoint 2013 Search

Crawling is the mechanism which SharePoint Search uses to go through all the items in a given content source and build an Index. All the search queries get executed against the Index to provide the search result. Outcome of the search always depends on the freshness of the Index. In other words, if the Index is very fresh/ recent, we have the ability of pulling fresh/ recent content as part of the search query. If the Index is very old/ outdated, search result will contain outdated search results.

SharePoint used to provide 02 mechanisms to crawl content from a content source – Full crawl and Incremental crawl.

  • Full crawl – this forces SharePoint to go through the entire content source, no matter what is the status of the Index and traverse through all the items from the first item through the last item and re-build the Index. This is what we do as the very first thing after we add a new content source. Time it takes to complete a full crawl is always depends on the volume of the content. If the volume is high, we don’t recommend running frequent full crawls.
  • Incremental crawl – this instructs SharePoint crawler to crawl only the modified content (added/ changed/ deleted) from the last full or incremental crawl. This takes less time to crawl since it doesn’t have to traverse through the entire content source and crawl the entire content source.

Most of the organizations, schedule incremental crawls depending on how frequent their content get updated. Incremental crawl starts at a particular time and repeats regularly at specified times.

SharePoint 2013 introduces an alternate option for incremental crawls – Continuous crawl.

  • Continuous crawl – this is a new option in SharePoint 2013 and it applies only to SharePoint Sites. Like incremental crawls, a continuous crawl crawls content that was added, changed, or deleted since the last crawl. Unlike incremental crawls, continuous crawl automatically starts at predefined time intervals. The default time interval is 15 minutes. This is the ideal option for crawling SharePoint content that is changing quickly/ frequently. With this, we can ensure freshness of Index and search result.
Configuring continuous crawl
  • Open SharePoint 2013 Central Administration web site
  • Select Manage service applications option from Application Management section
  • Select Search Service Application instance
  • Select Content Sources link under Search Administration links in left hand side
  • Select either New Content Source or your existing SharePoint content source
  • Select Enable Continuous Crawls for Crawl Schedules option and click OK.Crawl Schedules

Posted by Joy

Comments (1) Trackbacks (1)
  1. I’m curious as to why, when one selects “Enable Continuous Crawls” that the “Incremental Crawl” is automatically scheduled for “Every 4 hours”.

    I’ve had a difficult time getting continuous crawls to work. From looking at my logs, it looks like I’m able to run one FULL crawl, one INCREMENTAL crawl, and then the next INCREMENTAL crawl runs forever (I let one go for over 40 hours before killing it, just to see if it would ever terminate).


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