Central Finance – Lessons Learned SAP Landscape Transformation Replication Server (SLT)
Having been involved in various SAP project implementations we all know how critical the learning from a project are and how they can help us if we face the similar situation again.
We are a group of consultants at SAP dedicated to gather valuable lessons learned during CFIN projects and share within the external community. Our main objective is to elaborate on lessons learned in regards to SAP Landscape Transformation Replication Server in a CFIN project.
In a CFIN project SAP LT Replication Server collects data written to databases in the source systems (i.e. posted documents) and feeds this data into the corresponding Central Finance accounting interface via real-time replication.
SAP SLT server uses a trigger-based replication approach to capture the data to be passed in real-time from source system to target system.
In a typical set-up of a CFIN project, multiple source systems are connected to one System Landscape Transformation Replication Server, which in turn is connected to one Central Finance system.
SAP LT Replication Server is used for Initial load of some objects, i.e.:
- Initial load of CO internal postings,
- Initial load of Cost Objects,
- PCA Internal posting.
Note: Classic Initial Load of FICO posting is carried out via customizing in Central Finance.
SLT is also used for Real time replication of source documents, supported via CFIN interface, e.g.:
- Accounting Documents,
- CO Internal Posting ,
- PCA Internal Posting.
The following diagram represents the different interfaces that are available for replication from Source system to Central Finance.
To enable the SLT functions, you must configure communications between all the systems in the CFIN landscape and the SAP LT Replication Server.
You also need to have the SLT software component present (installed or embedded) on the relevant systems:
- Source systems
- SLT system
- Central Finance system
with the recommended release and support package and to apply all the needed notes.
Interface for Business Integration.
To implement the Central Finance scenario for an SAP ERP source system that uses a 3rd party database with a runtime-database license, you must use the “business integration” scenario in SLT which requires certain steps to be performed that are explained in the notes:
- 2223621 – “Central Finance: Interface for Business Integration”
- and 2223801 – “SLT – Central Finance: Interface for Business Integration”.
Third-Party System Integration
For information about connecting non-SAP ERP systems to Central Finance, see SAP notes:
- 2932517 – Central Finance Third-Party System Interface: Frequently Asked Questions (FAQ)
- 3067156 – SAP LT Replication Server for Central Finance – Third-Party System Integration 2021
- 2922300 – SAP LT Replication Server for Central Finance – Third-Party System Integration 2020
- 2713300 – “SAP LT Replication Server for Central Finance – Third-Party System Integration 1909”.
System Landscape Transformation (SLT) Sizing
To have the SLT replication working fine you have to size properly:
- The Network Connection
- The SLT Replication Server
- The source systems
- The CFIN system
SAP fully support this sizing exercise:
- Specifying the Input Parameters for a correct sizing
– Programs to gather statistic data for SLT sizing calculation
– Specific services
– The SLT Quick Sizing
– The SAP SLT Sizing Guide
Operate System Landscape Transformation (SLT)
The main activities in SLT are:
- Define Configuration/Objects for SAP LT Replication Server
- Initial Load
- Real-time replication
- Change recording
- Data Filtering
- Operate SLT
To operate SLT in a Central Finance project you need the following skills:
- Application Interface Framework (AIF)
This blog mainly focuses on lessons learned in using SLT in CFIN projects.
System Landscape Transformation (SLT) – Consideration & Challenges
Let’s consider one example of a challenge encountered in a real CFIN Project.
- AIF messages with error “Documents is already posted”. This scenario occurs if SLT tries to bring a posted document multiple times over to CFIN.
CFIN has a standard check to help prevent the posting of documents, multiple times.
- There are, however, rare cases when this check to prevent duplicate postings may not work if SLT transferred over the same document within a very short time period. This would mean that they can be processed in parallel across different jobs at the same time. Duplicate check does not work here because first document was not definitively posted before the other.
- Duplicate posting can occur when SLT transfer a change from source to target but cannot mark the processed record as “processed” in the source system. Then SLT could transfer the same record again (that will be recognized by the AIF-interface as a duplicate posting and marked as erroneous).
- RFC-connection problems can cause SLT to assume that records were not transferred and to try again. Look into alerts on RFC related errors in SLT to prevent them in future.
- Keep in mind this kind of issues and try to prevent them with appropriate actions.
System Landscape Transformation (SLT) Lessons Learned
- Install the SAP LT Replication Server System in a separate system.
- Adopt the highest SP /SPS level available for your DMIS add-on to use all available SAP LT Replication Server features.
- Make sure that you have the up-to-date version of each relevant SAP Note, as mentioned on the SLT Installation Guide
- Store the source system replication logging tables in a separate table space. So you can easily monitor the size of the log tables.
- Pay attention to all the various factors which influence the performance of the replication and size them properly following the recommended approach.
- Be prepared to recover in the right way in case of system outage, referring to the relevant Notes like: 2679070 – Central Finance: Starting or resuming SLT replication , 2581843 – Central Finance: Disaster Recovery Procedure after Crash of Central System With the Need to Restore From Backup CO part and 2504938 – Central Finance: Disaster Recovery Procedure after Crash of Central System With the Need to Restore From Backup
- Be sure to have followed the recommendations of the SLT Security Guide
- Filter rules are one of the important parameters in SLT and before starting SLT these should be discussed in detail
- Duplicate Posting Issue –Standard does a check to ensure a document is already posted. This check is against the database but if same document is passed by SLT in 2 separate AIF jobs, it can result in duplicate posting. Please have a look at the following Note: 2918829 – Central Finance: Duplicate postings due to parallel processing of AIF messages
Hopefully the above concepts, valuable experiences as well as lessons learned which we gathered from various projects and teams across our organization will help you to overcome similar challenges which you might face during your projects.
We invite you to post any feedback, ideas, or tell us how this content was helpful for your project.
Please find Q&A and post questions on the SAP S/4HANA Finance community.