A sandbox resource, whether it is a shared, local or partitioned sandbox (or an ordinary sandbox on a standalone Server), is specified in the graph under the fileURL attributes as a so called sandbox URL:

sandbox://data/path/to/file/file.dat

where data is the code for the sandbox and path/to/file/file.dat is the path to the resource from the sandbox root. The URL is evaluated by CloverDX Server during job execution and a component (reader or writer) obtains the opened stream from the Server. This may be a stream to a local file or to some other remote resource. Thus, a job does not have to run on the node which has local access to the resource. There may be more sandbox resources used in the job and each of them may be on a different node.

The sandbox URL has a specific use for parallel data processing. When the sandbox URL with the resource in a partitioned sandbox is used, that part of the graph/phase runs in parallel, according to the node allocation specified by the list of partitioned sandbox locations. Thus, each worker has its own local sandbox resource. CloverDX Server evaluates the sandbox URL on each worker and provides an open stream to a local resource to the component.

The sandbox URL may be used on a standalone Server as well. It is an excellent choice when graph references some resources from different sandboxes. It may be metadata, lookup definition or input/output data. A referenced sandbox must be accessible for the user who executes the graph.