Portrait Dialogue stopped responding (Error: "Exception: SSL Provider: The handle specified is invalid")



Portrait Dialogue (PD) stopped responding
  • Cannot connect with Dialogue Admin (DA)
  • Cannot connect with Visual Dialogue (VD)
  • Cannot get a connection with Portrait Process Monitor (PPM)
  • There are no errors being reported in the event log
  • Rebooting only works for a very short time, then PD hangs again
  • PD error logs show errors, which are victims of the problem, not the cause
    • Exception: SSL Provider: The handle specified is invalid
    • Exception: The request channel timed out while waiting for a reply
    • Errors having to do with saving message templates


The hanging most was likely related to performance load. 
The problem coincides with execution of a Dialog sending hundreds of thousands of messages in 6 parallel, groups concurrently.
If the load is too much for the server to handle and the throughput is not throttled via a suitable thread management policy, then it may eventually hang.  


UPDATED: April 11, 2017
To resolve the immediate problem:
  • Check the Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Million Handshakes\6.1\DialogManagerService MaxDialogTaskProcessingThreads 
  • If the number of threads is set to a high number such as 16, reduce it to a low number, such as 2.  This will allow the server to manage the load, albeit at a slower pace.  
  • Experiment with this setting (MaxDialogTaskProcessingThreads) increasing the number of threads to increase the performance, while still keeping the server from freezing.