Execution mode: Synchronous or Asynchronous
Asynchronous and synchronous define how the client (the application using the task) interacts with the server and gets the result from the task. When a service is set to synchronous, the client waits for the task to finish. Typically, a synchronous task executes quickly—five seconds or less. An asynchronous task typically takes longer to execute, and the client must periodically ask the server if the task has finished and, if it has finished, get the result. A web application using an asynchronous task must have logic implemented to check the status of a task and handle the result once execution is finished. ArcGIS Desktop clients handle both execution types natively.
View result with a map service
When publishing a geoprocessing service, you can choose to view the result of all tasks within the service as a map (in addition to other results of your task). The map image is created on the server a map service and transported back to the client as an image (a .tiff, with style information). The symbology, labeling, transparency, and all other properties of the map image to be returned are the same as the output layer in your current ArcMap session. There are several reasons why you would use a result map service:
If your output layer is drawing unique values, you might need to uncheck <all other values> in the layer properties to force recalculation of the unique values prior to drawing. See Creating a layer symbology file for more details.
If you want the client to only view the data and not be able to download data, set the Maximum Number of Records Returned by Server option to 0 (zero) when publishing.
You can return messages of varying levels to the client that executed your geoprocessing service.
Maximum Number of Records Returned by Server
The maximum number of results the service can return to a client. Setting this value to a large number means your GIS server can handle sending a lot of individual records or features to the client. If you don't want to return any features, set this value to 0 (zero). Typically, you set this value to zero only when you enable View result with a map service.
The directories used by the server to write files when executing a task.
Some geoprocessing service settings can only be set inside the ArcGIS Server Administrator Directory web page. These advanced settings cannot be configured from ArcMap or ArcGIS Server Manager.
Modifying the properties of an existing service
All the service properties listed above can be modified after the service has been published. You will need at least a publisher or administrator connection to modify the settings. These settings can be applied on a service that is already running or stopped. If modifying the settings of a running service, it will be restarted when you apply the settings.