When reviewing the STDERR log file the following errors are logged:
20140211 120003.280 t1190 GEN 2161:30 ### ERR detect ESASL_GSSAPI_MAJOR 0 init_sec_context: Failure
20140211 120003.280 t1190 GEN 2161:3c ### ERR detect ESASL_GSSAPI_MINOR 0 init_sec_context: No credentials are available in the security package
And the Quick Connect Virtual Directory Server software experiences slowdown issues, followed by the eventual failure of connections.
These errors ("No credentials are available in the security package") are typically given by the Kerberos library when impersonation is not properly setup in the environment.
Changes at the delegation/impersonation configuration of the object at the domain controller take time to propagate to the members (up to 15 minutes) and restarting the member server forces the update. And it is possible this may have caused the errors seen above.
It is recommend that, unless a strong reason is needed to use Impersonation in the setup, change the connection pool to normal SASL because this would avoid an extra operation and simplify the functionality.
But if there are no more changes in the setup this error shouldn’t be occurring again.