The DataImportHandler stopped working for our JDBC connection to SQL Server after deploying to a new production environment.
When querying the import status it would just report "busy". We attached the SQL Profiler to our SQL Server and saw that when an import was requested that it touched the SQL Server to do an authentication test (can't recall exact message) so we knew the connection strings and configuration were correct, but that is where communications ended. We attached the SQL Profiler to a functioning "development" environment and found that after initiating import that there was a lot more activity after the authentication line. This helped us isolate it to environment versus configuration. Note: we thought perhaps it was related to Java 32bit versus 64bit environment (as these differed also) but after installing consistent Java environments we continued to have the problem. We rolled Tomcat back to v7.0.19, to be consistent with our other production environments, and our imports started functioning again.
