How-to Manage House-Cleaning in the System Landscape Directory – Duplicate System Entries

Last updated: March 31, 2020

Why Do House-Cleaning in the SLD – and how?

Few people would regard this task fun, and if systems update their data regularly in the SLD using SLD data suppliers, and three mechanisms of data distribution between SLD systems (forwarding of data supplier data, export/import of data Better Manage SLD Exports and Imports Using CTS+ and Demo: The Full Automatic Sync Feature in the SLD of SAP NetWeaver 7.1) then why do you have to do it at all?

Is this “TE2” system entry a duplicate that needs to be removed or not?

Fact is, that data suppliers are an excellent way to gather new data and data updates – the push mechanism triggered by the systems themselves significantly simplifies the work of the SLD administrator – but are not used to remove data of systems that no longer exist. The reason behind this is simple: Should a system be removed only because its data-supplier didn’t report to the SLD last time it was normally scheduled? This cannot be done, simply, because this “date” might have been missed during system maintenance. Is the second missing report sufficient? We don’t think so: when the system is still in use, business processes based on PI messages or Web Dynpro (Java) based UIs would fail unnecessarily…
On the other hand no-longer-existing systems but still visible in the SLD might be assigned to business processes erroneously, which will not work then, and that’s why you as the SLD’s administrator have to take care of outdated systems data. Keep in mind: Most or all of the manually created data such as business systems should be updated be development and therefore should not be your problem.

House-Cleaning in Your SLD – Best Practices

Consistent Deletion of Managed Systems — System Decommissioning

The SCN Wiki document Delete_Managed_Systems (https://wiki.scn.sap.com/wiki/display/SMSETUP/Delete_Managed_System) describes the steps necessary for consistent handling of deletion of technical system data depending on your version of SAP Solution Manager. This needs to be considered first if a system has ever been used in SAP Solution Manager.

Data Changes in the SLD

Let’s see how you can recognize and deal with outdated data in various releases of the SLD.

Note: You will have to clean up technical systems’ data in all your SLD systems independently of their release: Even if you are using a “central” SLD as a target for all data suppliers and forwarding data to other SLD systems in your landscape, deletions will not be forwarded. Full automatic synchronization would do that, however, I do not recommend using it for that purpose instead of connections where forwarding of landscape data is proposed since it does not provide filtering and would also replicate unneeded or misleading data such as productive data for business systems into development.

Recognizing Outdated Data

If a technical system used as a business is uninstalled, in many cases it will be replaced. If it is re-installed on a different host, it might get the same SID (three character system identifier). This will not cause a problem for the SLD because with a different host name the record is still unambiguous.
Does that help to remove such data automatically? No, it does not: the second identical SID might for example be the result of a merger and also valid. Therefore, a decision of a human being is required.

SLD UIs of SAP NetWeaver 7.0 and Earlier

In these systems, all data of technical systems need to be updated manually after a system was moved. Outdated system data need to be deleted, if the old system – or the old host respectively – can no longer be reached.

Note: All data using technical systems‘data such as business systems and JCo destinations need to be associated manually with the updated data or newly created.

There are two ways to get rid of outdated data:

• You can directly remove technical systems from the list under SLD Home / Landscape / Technical Systems
• It’s easier, however, to choose SLD > Administration > Automatically Updated Data or in later releases > Administration > Maintenance > Automatically Updated Data:
  Displaying automatically updated SLD data
  
  You’ll find an overview of all SLD data suppliers ordered by Name, Type, and Date of last update of system’s data in the SLD:
  This view allows sorting and filtering and directly supports deletion of selected system data (button Remove) and thus simplifies the manual part of data maintenance – if TE2 on tewdf232933 was moved or deleted you can remove it here – note that it didn’t report to the SLD for more than 2 weeks

SLD UIs of SAP NetWeaver 7.1 and Higher

As of SAP NetWeaver 7.1 situation in the SLD is as follows:

• Obviously , the same mechanisms to delete outdated data described  above also work and for deletions of systems that are not replaced, this is still the way to handle this situation
• Additionally you’ll find a function to deal with systems, which have been moved especially:
  Under SLD / Home > Technical Systems > Details choose button Move:
  This view allows sorting and filtering and directly supports the move – its assignment to a new host – of selected system data (button Move) and thus simplifies the manual work.Also see 1817310 – Double Stack System automatic move functionality
• Enter the new host:
  All associated data will be updated for example JCo destinations when new data is saved. If for example TE2 was moved from tewdf232933 to tewdf231930 it could be corrected here easily.

The benefit of the latter approach is that all data associated with technical systems’ data are updated automatically: No further manual work is necessary.

Final Remark

So no matter what release of the SLD you run: In addition to regular updates of imported SLD data (CR Content and CIM model updates are described in SAP Note 669669) also ensure that you provide clean landscape data as a basis for flawless performance of all your SLD’s client applications. If changes in systems are done on a regular basis in your company and the updated functions are important read in another blog “How to Get an SAP NetWeaver 7.1 System Landscape Directory??”.

Additional Reading

More information on the topic of removing unwanted data from the SLD can be found in SAP Notes:

• Note 1160192 – System description in SLD contains obsolete elements
• Note 1159969 – System description in the SLD contains duplicate elements
• Note 1747926 – Dealing with duplicate technical system names (older SLD)
• Note 1694004 – Dealing with duplicate technical system names (SIDs)
• Note 1727294 – AS Java/ABAP System move functionality