Comment 1 for bug 794933

On the service side a JDBC query can be canceled via Statement.cancel() and a rollback().

http://stackoverflow.com/questions/1054642/how-can-i-cancel-a-long-running-query-using-spring-and-jdbctemplate

Since we are now using REST as the external service API it should be possible to abort the HTTP request and get informed about this by the Grizzley REST service.