Unresponsive child for request

I am getting this error in my logs and I understand it is do to likley an issue with sql but was wondering what the criteria for this error to be generrated is. Error: WARNING: Unresponsive child for request 271737, in module sqlzuul component accounting Basically I assume and sql query is sent and if there is no response in x seconds this error is generated. Or am I completly wrong here? Mark Jones