You can configure the Data Integration Service to run jobs in the service process. Configure this option when the service runs SQL data service and web service jobs on a single node or on a grid. All nodes in the grid must have both the service and compute roles.
When you enable a Data Integration Service that runs on a grid, one service process starts on each node with the service role in the grid. The Data Integration Service designates one service process as the master service process, and designates the remaining service processes as worker service processes. When a worker service process starts, it registers itself with the master service process so that the master is aware of the worker.
The master service process manages application deployments and logging. The worker service processes run the SQL data service, web service, and preview jobs. The master service process also acts as a worker service process and completes jobs.
The Data Integration Service balances the workload across the nodes in the grid based on the following job types:
SQL data services
When you connect to an SQL data service from a third-party client tool to run queries against the service, the Data Integration Service dispatches the connection directly to a worker service process. To ensure faster throughput, the Data Integration Service bypasses the master service process. When you establish multiple connections to SQL data services, the Data Integration Service uses round robin to dispatch each connection to a worker service process. When you run multiple queries against the SQL data service using the same connection, each query runs on the same worker service process.
Web services
When you submit a web service request, the Data Integration Service uses an external HTTP load balancer to distribute the request to a worker service process. When you submit multiple requests against web services, the Data Integration Service uses round robin to dispatch each query to a worker service process.
To run web service requests on a grid, you must configure the external HTTP load balancer. Specify the logical URL for the load balancer in the web service properties of the Data Integration Service. When you configure the external load balancer, enter the URLs for all nodes in the grid that have both the service and compute roles. If you do not configure an external HTTP load balancer, web service requests are not distributed across the nodes in the grid. Each web service request runs on the node that receives the request from the web service client.
Previews
When you preview a stored procedure output or virtual table data, the Data Integration Service uses round robin to dispatch the first preview query directly to a worker service process. To ensure faster throughput, the Data Integration Service bypasses the master service process. When you preview additional objects from the same login, the Data Integration Service dispatches the preview queries to the same worker service process.