Just a quick note for anyone that used MOSS/SharePoint 2007 and is wondered why the option to change the indexer performance has been removed in SharePoint 2010/2013. Well worry not SharePointer, it is still there.
Where is it in SharePoint 2010/2013?
So if you want to stop SharePoint crawling to stop hammering SQL for whatever reason run:
Get-SPEnterpriseSearchService | Set-SPEnterpriseSearchService –PerformanceLevel “Reduced”
The different levels mean:
Reduced: Total number of threads = number of processors.
Partly Reduced: Total number of threads = 4 times the number of processors.
Maximum: Total number of threads = 16 times the number of processors.
There’s no mention of any restart requirement but I’d not be surprised if any active crawls need to be restarted to see the new value.
Crawler Impact Rules
There is of course another way of stopping SharePoint Denial-Of-Service (DOS) attacking either itself or an external content-source. That would be via “Crawler Impact Rules” in the Search Administration page.
Add rules here to ensure the crawler reads gently from specific locations if the crawl is overwhelming whatever it is being crawled.
More info @ http://technet.microsoft.com/en-us/library/cc261720(v=office.12).aspx – this was introduced in MOSS but the concepts are still the same, even in 2013. Credit to my colleague Miguel A Ballesteros Mesa for helping on this post.
// Sam Betts