Parts of DDM
DDM consists of several parts to handle remote file processing among the systems using DDM.
- Source DDM (SDDM)
- Target DDM (TDDM)
- DDM file
The preceding figure shows how the basic parts involved in DDM communications on both systems relate to each other.
When a DDM file is accessed by a source system user or program, a DDM conversation is started between SDDM and TDDM for the job in which the program or user is operating.
- Parts of DDM: Source DDM
The support on the source (or local) iSeries server is started, as needed, within a source job to do DDM functions. - Parts of DDM: Target DDM
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. - Parts of DDM: DDM file
A system object with type *FILE exists on the source server to identify a remote file. It combines the characteristics of a device file and a database file. As a device file, the DDM file refers to a remote location name, local location name, device name, mode, and a remote network ID to identify a remote server as the target server. The DDM file appears to the application program as a database file and serves as the access device between a source server program and a remote file.