Technical Bulletin: WCF services may become unresponsive after running with high load

Initial publication: April 8, 2011
Last reviewed on: July 15, 2011

Last updated on: April 8, 2011 

WCF services with high amounts of activity become unresponsive and the operations may begin to fail. All other WCF services on the machine hosting the unresponsive service may also become unresponsive. 


  • You are NOT running Windows Server 2008 or Windows Server 2008 R2.
  • You are unable to conduct operations after a large amount of activity has been conducted.
  • Restarting the server allows operations to continue OR deploying services to another node allows operations to continue (if SMART Manager is not running on the affected machine.
  • The following error is observed in the SaaSGrid Operations Center (from any source): Insufficient winsock resources available to complete socket connection initiation.


Apprenda has closed this issue as attributable to an external factor. 

We observe that this issue affects WCF services not deployed by SaaSGrid in addition to ones that are deployed by SaaSGrid, thus SaaSGrid is not directly attributable to the cause. After further testing, the issue only been observed on Windows Server 2003 and Windows Server 2003 R2. It does not occur on Windows Server 2008 and Windows Server 2008 R2. Load testing specific to this issue has not been conducted on other operating systems supported by SaaSGrid at the time of this writing. 

SaaSGrid's guidance is that customers expecting to operate under high load in a production setting use Windows Server 2008 or Windows Server 2008 R2. It is not believed that a fix for the Windows Server 2003 family of operating systems is forthcoming. 

Is there a Manual Workaround?

If the symptoms apply, restart the server hosting the unresponsive service. It is possible to avoid the symptoms for a longer period of time by deploying additional copies of the service(s) via the SaaSGrid Operations Center. 

Applicable Component(s):

  • SaaSGrid Service Container
  • SMART Manager

Affected Version(s):

  • All SaaSGrid Versions