A target server job is started on the target (or remote) server as a result of an incoming DDM request and ends when the associated DDM conversation ends.
The target DDM (TDDM) translates DDM requests for remote file access into data management requests on the target server and then handles the return of the information that is to be sent to the source server.
The TDDM is started when the remote server sends a program start request. The TDDM is started as a batch job on the target server. After the TDDM is started and a DDM conversation is established, the TDDM waits for a request (such as a file open or read operation, or a nonfile-related operation) to be sent by the SDDM.
When the TDDM receives a request to access an object on the target server, it searches for the requested object. If the object was not qualified with a library or path name, the current library list or current directory for the target job is searched.
When the requested object is found, the TDDM passes the first operation requested to database or folder management on the target server, which performs the operation on the object. When the operation is completed, database or folder management services return the results of the operation to the TDDM, which passes it to the SDDM. The SDDM passes the results and any accompanying data (such as records requested on a read operation) to the application program. These actions are repeated for each subsequent I/O operation request received, until the object is closed. If an operation does not complete successfully, the SDDM returns an error message to the program, providing information about the error.
The TDDM and the target job remain active until the DDM conversation is ended by the source server job that started it.