Description

Tasks of the transport dispatcher program RDDIMPDP
Each export from a source system and each import into a target systemcan be split into different phases or transport steps. Some of thesesteps are performed by external programs (tp and R3trans) and some byABAP programs within the system. The task of the program RDDIMPDP is tostart and monitor all steps performed by ABAP programs.
The external transport control program tp uses entries in the tablesTRBAT and TRBATC to pass information on the transport steps. Thisinformation includes the type of transport step (function), thetransport requests involved and possibly the client where the transportstep is performed. tp then triggers an SAP event of the transportdispatcher to start RDDIMPDP as a background job in client 000.
To perform the transport steps, RDDIMPDP starts the corresponding ABAPprograms in separate background processes. Information on thebackground processes that have been started is placed in the tableTRJOB. This table is then used later to check the status of theprocesses. If a step ends successfully, or if it runs with errors, thenan appropriate entry is made in the tables TRBAT and TRBATC. tpanalyzes this information and then deletes it from the tables TRBAT andTRBATC.

Client-specific transport steps
Transport steps are usually performed in client 000, since thecorresponding programs mostly edit cross-client data only. Only theexport and import of ADO objects (application-defined objects), such asnumber ranges, takes place in other clients (the export in the sourceclient of the corresponding transport request or change request; theimport in the same client as the export, if no target client isspecified).
The program RDDIMPDP in client 000 recognizes that an action must beperformed in another client and triggers a client-specific SAP event.This starts RDDIMPDP as a background job in this client. RDDIMPDP thenstarts the corresponding ABAP program in a separate background job.

Names of the background jobs
Use this overview of the various background jobs involved in thetransport to monitor the progress of the transport in theJob Overview (Tools -> CCMS -> Jobs -> Maintenance(Transaction SM37)).
Note
If you also want to display jobs that are not scheduled for a definitestart time, enter * in the field or after event: on thejob overview selection screen.
The transport dispatcher RDDIMPDP is scheduled as an event-controlledbackground job. To help identification, the name of the job containsthe client where it is scheduled. The triggering SAP event is alsoclient-specific.
Client Job name triggering event withparameter
000 RDDIMPDP SAP_TRIGGER_RDDIMPDP
nnn RDDIMPDP_CLIENT_nnn SAP_TRIGGER_RDDIMPDP_CLIENT nnn
The ABAP programs started by RDDIMPDP depend on the transport stepentered in the function field of the table TRBAT:
Function Job name Description of the transport step
J RDDMASGL Activates ABAP Dictionary objects
M RDDMASGL Activates matchcodes and lock objects
S RDDDIS0L Analyzes the database objects for conversion
N RDDGEN0L Converts database objects
Y RDDGEN0L Converts matchcode tables
X RDDDIC0L Exports ADO objects
D RDDDIC1L Imports ADO objects
E RDDVERSE Executes pre-export methods (such as
creation of versions)
W RDDVERSI Creates versions before the import
V RDDVERSL Updates version management before import
F RDDVERSK Creates versions after the import
R RDDEXECL Executes post-import methods
G RDDDIC3L Generates ABAP programs and screens

Precondition
To enable the transport to run without errors, the program RDDIMPDPmust be scheduled as a background job in client 000 and in all clientswhere data is being imported or exported. This job is scheduledautomatically when you use the standard client copy tools to create anew client. However, you can schedule the job at any time, for example,if you only find out that it is not scheduled when the transport isalready running.
To schedule the program RDDIMPDP as a background job, log on to theappropriate client as a user with CTS administration authorization andexecute the program RDDNEWPP in theABAP Editor (Tools -> ABAP Workbench ->Development -> ABAP Editor (transaction SE38)).
RDDIMPDP starts the transport steps in separate background processes.This means that there must be (at least) two background processesavailable in the R/3 System (profile parameter rdisp/wp_no_btc). If thesystem runs on multiple application servers you can distribute thesebackground processes across them.
The transport control program tp must be able to communicate with themessage server of the SAP System to be able to trigger the SAP eventfor starting RDDIMPDP. This is guaranteed if tp is started on anapplication server of the SAP System where the export or import takesplace.
This is always the case for imports and exports started within the SAPSystem (from the Transport Organizer or the Transport ManagementSystem). For imports started at the operating system level, it dependson the host where tp is called.
For more information on communication between tp and the messageserver, see Note 11677 in the SAPNet - R/3 Frontend.