Identify the missing word(s) in the following sentence within the context of Microsoft Azure. [?] uses a clustered architecture. Each cluster has a control node that is used as the entry point to the system. When you run Transact-SQL statements or start Spark jobs from a notebook, the request is sent to the control node. Each task is sent to a compute node to actually do the processing. The control node gathers the results from the compute nodes and combines them into an overall result.