SharePoint 2010: How to Configure Search Time-Out Settings
Use this procedure to set the timeout values for the search system to use when attempting to connect to a content repository and when waiting for a response to the connection attempt.
Verify that the user account that is performing this procedure is an administrator for the search service application.
In Central Administration, in the Quick Launch, click General Application Settings.
On the General Application Settings page, in the Search section, click Farm Search Administration.
On the Farm Search Administration page, in the Farm-Level Search Settings section, click the value of the Time-out (seconds) setting.
In the Search Time-out Setting dialog box, in the Connection time (in seconds) box, type the number of seconds that you want the search system to wait when attempting to connect to a content repository.
In the Request acknowledgement time (in seconds) box, type the number of seconds that you want the search system to wait for a content repository to respond to a connection attempt.
Click OK.