SharePoint Full, Incremental and Continuous Crawl

This SharePoint 2013 search tutorial explains, different types of crawls in SharePoint Online/2013/2016 like Full crawl, Incremental crawl, and Continuous crawl.

Different types of SharePoint Search Crawl

There are three types of crawl like below:

  • Full crawl
  • Incremental crawl
  • Continuous crawl

SharePoint Search Full Crawl

In SharePoint Full Crawl of the Content source will re-index all the content from the beginning.

Important Points to Consider:

  • If a new managed property has been introduced, we need to run Full Crawl of the content source
  • If new crawl rules are created/updated/deleted, Full crawl of the content source is required
  • If incremental crawl has been failed
  • If software update or service pack has been installed on the servers
  • Expensive in terms of performance issues

SharePoint Incremental Crawl

In the case of SharePoint Incremental Crawl of the Content source will only process those items which are changed since the last crawl happened.

Important Points to Consider:

  • Most preferred after the full crawl has been done.
  • Does not hamper the performance as it will crawl only modified documents, not the entire content source.
  • The incremental crawl will retry items and postpone crawling the item if the error persists.
  • A limitation with the Full Crawl and Incremental Crawl is we cannot schedule both to execute parallel. For example, if the Full Crawl is already running then the Incremental Crawl cannot be triggered until the Full Crawl completes, if you try to Stop Full Crawl then also it is mandatory to finish at least once successful Full crawl before triggering any Incremental Crawls.

So Microsoft has come up with the concept of Continuous Crawl

SharePoint Continuous Crawl

  • With SharePoint Continuous Crawl, you can maintain the content index as fresh as possible.
  • More than one continuous crawl can run in parallel
  • One deep change will not result in degraded freshness on all following changes
  • The impact of a “Continuous Crawl” is the same as an incremental crawl.
  • At the parallel execution of crawls, the “Continuous Crawl” within the parameters defined in the “Crawler Impact Rule” which controls the maximum number of requests that can be executed by the server (default 8).
SharePoint Full Incremental and Continuous Crawl

Enable Continuous Crawl using PowerShell in SharePoint

We can also enable Continuous Crawl using PowerShell in SharePoint 2013/2016.

#Get Search Service Application(SSA)
$ssa = Get-SPEnterpriseSearchServiceApplication
#Get the Content Source for which you want to enable continuous crawl
$cs = Get-SPEnterpriseSearchCrawlContentSource -SearchApplication $ssa -Identity "Local SharePoint sites"
#Set the EnableContinuousCrawls property to true
Set-SPEnterpriseSearchCrawlContentSource -Identity $cs -EnableContinuousCrawls $True
#Set the interval – You can skip this part by default SharePoint will run continuous crawl for every 15 minutes. Here I am using 30 minutes
$interval = "30"
$ssa.SetProperty("ContinuousCrawlInterval", [int]$interval)

To Disable Continuous Crawl using Powershell in SharePoint

We can use the same PowerShell script mentioned above, with the following change in the line where we need to set ‘EnableContinuousCrawls’ property to ‘False’.

Set-SPEnterpriseSearchCrawlContentSource -Identity $cs -EnableContinuousCrawls $True

You may like following SharePoint tutorials:

Here we learned various Full, Incremental and Continuous Crawl in SharePoint, and also we discussed, how to enable or disable Continuous Crawl using Powershell in SharePoint 2013/2016.