SAP SLT Architecture (Detailed Guide)

10. October 2022

SLT, in essence, is an Extract, Transform, Load (ETL) tool, enabling you to load, replicate, or schedule data in real time. You can do the same from any SAP-related source or system into the coveted SAP HANA database.

It usually uses a basic trigger-based replication approach, which is done whenever you have a lot of data populating the logging table. Hence, in a way, it helps maintain your data flow and ensures that you are keeping everything neat and clean.

What Are The Benefits Of An SLT Infrastructure?

Having an SLT infrastructure in your SAP-based ecosystem can prove to be highly beneficial for you. Please keep reading to know more about this aspect.

  • It can enable you to schedule or make a data replication in real-time.
  • You will be able to handle Pool and Cluster tables quite easily.
  • It will be possible to migrate data in SAP HANA format while replicating data.
  • The system can offer support to both Unicode and non-Unicode conversion during the replication or load procedure.

In addition to these, the SLT infrastructure can also be integrated with SAP HANA entirely. It will help you get access to more and more transformation capabilities. Also, if you add SAP HANA Solution Manager with it, you will get some monitoring abilities in your hands.

What Is Available In A SAP SLT Infrastructure?

The SAP SLT structure comes with five different segments as a whole. Each of them is quite different from the other and, therefore, has to be learned about separately.

Here’s what you need to know about them.

The Read Engine.

The read engine of the system is going to be responsible for reading a piece of data from the logging table. Once it’s done, it’ll pass the same to the SLT replication server.

DB Triggers.

The DB triggers are subjected to monitoring any kind of event, such as delete, insert, modify, or update, that takes place in a table. These are usually created on the Source System.

Logging Tables.

Once DB triggers, then the logging tables will begin storing triggered data. It, in turn, will be modified in the Application Table. The logging table will be curated in the source system.

Write Engine.

The write engine of the system will be responsible for writing the information within HANA from the replication server. You’ll have to start it manually before letting it work.

Transformation And Mapping Engine.

It will take the responsibility of creating a structured transformation of data as the target DB format of HANA requires you to be. 

How Does SLT Work?

In this section, we will talk about the common working procedure of SLT and how the whole replication process works. So, let’s get started with it.

  • At first, the SLT replication server will access the core source system by establishing an RFC connection. And, to do so, you’ll need to create a communication user with a specific authorization or two. This person will be able to access the source system but won’t be able to execute any kind of steps in the dialog mode.
  • Once you have created the replication server within the system, you’ll have to curate a brand new configuration in it as well. It should specify information regarding the core connection to the target system and the source.
  • After that, you’ll need to start monitoring and managing the replication process in the SLT replication server. You may use the SAP LT replication server Cockpit for it.
  • If needed, you can also boost the performance of the replication process and the initial load in the SLT replication server system.
  • Besides, you cam also specify advanced replication settings to fulfil various business requirements in the SLT replication server system.

Finally, the SLT server will transform and format the data according to the HANA format, and the write engine will send the same to HANA DB.

The Installation Approaches

When it comes to installing SLT, you can approach the process in more than one aspect. Here, in this section, we’re going to explain two of them. So, please be with us till the end.

Installing SLT On Source System.

If your infrastructure’s source system is based on SAP ABAP, it can be installed directly on it without any fuss. The administration and landscape of the procedure will be simplified. 

Nevertheless, the whole procedure’s performance might be impacted due to software maintenance dependencies. Besides, the multi-system support offered by the same will have a hugely-negative impact on the same as well.

Installing SLT As A Core Standalone System.

In this case, SLT will have its own dedicated application-based server with the DMIS add-on. Hence, the issue of software dependency will be literally non-existent here.

In addition, the flexibility of the whole program will be top of the chart as well. However, the maintenance effort on a brand new server might increase the investment requirement a little.

Which One Is The Best?

In essence, each of the aforesaid approaches comes with its own pros and cons. However, it might be best for you to install SLT as a standalone project. In this case, the dedicated server of SLT will lower the impact of the target systems and sources.

Also, using and installing the SAP LT replication server within the target system will only be recommended if you’re trying to replicate data. Even in that case, you might face more than one issue, like software issues or the burden of a multi-support system. And, that’s all.

The Bottom Line

Overall, the SLT structure is a highly effective, low maintenance, and easy-to-use tool that can help you easily replicate any data. Besides, it can help you with data governance thanks to excellent data processing and fast analytics.

It’s a tried and tested solution for easy and simple data replication that can break open several uglier parts of SAP models. For instance, you can use it to read data from both Cluster and pool tables pretty efficiently. And the risk of data loss will be quite low here as well.

So, if you want to transfer data in a real-time environment, opting for SLT instead of using a data replication product will be important. It might take a little bit more investment than usual, but it will work much better than anything else available out there!

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Frequently Asked Questions

 

  1. What is the primary difference between a “Load” and a “Replication” in SLT?

A Load is a one-time event where all current data from a source table is transferred to the target database. Replication is an ongoing process in which changes in source tables are captured using triggers and forwarded to the target system. The timing of updates depends on system configuration and workload.

  1. Why is SLT preferred for handling SAP Pool and Cluster tables?

Pool and Cluster tables store data in SAP‑specific compressed formats. SLT includes conversion logic to read and transform this data into a relational structure suitable for target systems.

  1. How do Database Triggers and Logging Tables work together?

Database Triggers are created on the source system to “watch” for any data modifications. When a change occurs, the trigger captures that event and records it in a Logging Table. The Read Engine then looks at these logging tables to identify exactly which records need to be moved to the SLT server, helping the system determine which records require transfer to the replication server.

  1. Can SLT handle data movement between systems with different languages or encodings?

Yes. SLT offers options for handling Unicode and non‑Unicode systems, supporting consistent character conversion during transfers, even when migrating between legacy systems and modern SAP HANA environments.

  1. What are the risks of installing SLT directly on the Source System?

While installing SLT on the source system simplifies the landscape, it may increase resource usage on the source application, so organisations typically evaluate performance impact before choosing this option. Additionally, software updates for SLT could be restricted by the maintenance schedule of the entire source system.

  1. Is a Standalone SLT installation worth the extra investment?

A standalone installation provides a dedicated environment for SLT processing, helping separate replication workloads from business applications. Whether this is beneficial depends on the organisation’s landscape, performance requirements, and infrastructure strategy.

  1. How do I monitor and manage the replication process?

Management is primarily handled through the SAP LT Replication Server Cockpit (Transaction LTRC). This interface allows administrators can review replication status, adjust configuration parameters, and manage table loads through the SLT cockpit.

 

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Benjamin Ng

Benjamin Ng leads B2B marketing at cbs consulting, working across Asia Pacific to help organisations translate strategy into measurable business impact. He is passionate about creative content and the role of technology—particularly SAP S/4HANA—in improving productivity and enabling transformation.

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