SAP HANA, SLT, LT Replication Server, Landscape Transformation, FAQ, Data Provisioning
1. What is the basic concept of SAP LT Replication Server (SLT)?
2. Where do I find central information about SAP LT Replication Server (SLT)?
3. How much load will be additionally generated by using SLT?
4. Where do I find more information about SAP LT Replication Server configuration?
5. Where do I find more information regarding SLT Monitoring setup on SAP Solution Manager 7.1 and BI Monitoring?
6. What happens if there are structural changes on tables with active DB trigger?
7. Can tables with more than 2 billion records be replicated via SLT into a HANA table?
8. How can the consistency between the source and target system be checked?
9. How can I find the proxy table for a source table?
10. How can I find the source table for a logging table?
11. How can typical SLT performance issues be optimized?
12. Can SLT tables be partitioned?
1. What is the basic concept of SAP LT Replication Server (SLT)?
The SAP Landscape Transformation (SAP LT) Replication Server is the SAP technology that allows you to load and replicate data in real-time from ABAP source systems and non- ABAP source systems to an SAP HANA environment. The SAP LT Replication Server uses a trigger-based replication approach to pass data from the source system to the target system. If not all data records of a table should be transferred, you can create transformation rules to selectively filter the data (selective data replication) or to enable other transformations during the data replication process.
2. Where do I find central information about SAP LT Replication Server (SLT)?
This SLT community page provides even more than current released SLT presentations, official roadmap information and all official SLT documents like installation and operation guides.
The SLT help page - https://help.sap.com/sapslt
The following important SAP Notes for SLT exists. Check regularly for updates available in the Operations Guide.
SAP Note
Title
1605140 Central Note - SAP LT Replication Server
1691975
HANA LTR - Clarification on DMIS releases
1768805 SAP LT Replication Server: Collective Note - Non-SAP Sources
1733714 Guide for Advanced Replication Settings
1963522 Limitation for SAP LT Replication Server on MaxDB
3. How much load will be additionally generated by using SLT?
It depends how many transfer jobs you have configured in your SLT system. Each transfer job will need a dialog job in source (RFC). When you are doing initial load (which should only happen once) and you are using collective Access plan you will need additional background jobs in the source. It should be avoided to configure too many transfer jobs (called Data Load Jobs) for the number of replicated tables and the troughput of changes.
4. Where do I find more information about SAP LT Replication Server configuration?
For each SAP LT Replication Server configuration, the parameter Data Transfer Jobs restricts the maximum number of data load jobs which can be started for one mass transfer ID (MT_ID).
In total, one mass transfer ID requires that the following background work processes are available in the SAP LT Replication Server:
1 monitoring job (IUUC_MONITOR_<MT_ID>)
1 master controller job (IUUC_REPLIC_CNTR_<MT_ID>)
1 job for either defining the migration objects (IUUC_DEF_MIG_OBJ_<2digits>), calculating the access plan (ACC_PLAN_CALC_<MT_ID>_<2digits>), or for changing configuration settings.
N data transfer jobs (DTL_MT_DATA_LOAD_<MT_ID>_<2digits>)
In the source system, the number of available dialog work processes which are reserved for the replication should be equal to the number of data transfer jobs running in the SAP LT Replication Server system.
5. Where do I find more information regarding SLT Monitoring setup on SAP Solution Manager 7.1 and BI Monitoring?
SAP Note
Title
1743562 ST-A/PI 01P: SLT Monitoring requires manual corrections
1558756 Solution Manager 7.1 - BI Monitoring for SLT Systems
1666278 Solution Manager 7.1 - BI Monitoring: Prerequisites
6. What happens if there are structural changes on tables with active DB triggers?
When a table is registered for replication, a corresponding logging table and a database trigger are created in the source system to record any INSERT, UPDATE, or DELETE statements.
The question is now how the SLT system and the source system behave regarding any structural changes to a table for which a DB trigger is active.
As the behavior depends on the SAP Basis release on the source system the behavior is described for the respective Basis version in the LT Replication Operations Guide.
For the SLT System we strongly recommend to use DMIS 2011 SP12 or higher. If you use an older SLT version you have to stop and restart the replication for the affected tables in any case. As the behavior is the same no matter if the structural change is done directly in the system or executed within a transport, we do not have to distinguish between both use cases.
7. Can tables with more than 2 billion records be replicated via SLT into a HANA table?
Yes, tables with more than 2 billion records can be replicated and partitioned within SLT. For more information check 2528241 - Partitioning of tables replicated by SLT to SAP HANA database.
For best practices for partitioning tables see SAP note 2044468 (Section 13).
8. How can the consistency between the source and target system be checked?
The consistency between source and target system in an SLT scenario can be checked using the cross-database comparison (CDC) feature. See SAP Note 2602264 for more details.
9. How can I find the proxy table for a source table?
SAP Note 2738066 describes how to find the proxy table for a source table using transaction LTRC or table IUUC_TAB_ID.
10. How can I find the source table for a logging table?
You can find the source table for a logging table in the following ways:
Logging table system, table DD02V: TABNAME -> source table, DDTEXT -> logging table
Source table system, table IUUC_TABLES: TABNAME -> source table, SHADOWTAB_NAME -> logging table
11. How can typical SLT performance issues be optimized?
The SLT Performance Guide contains comprehensive information for optimizing the SLT performance.
SAP Note 2000002 ("How can SLT specific performance issues be tuned?") describes tuning approaches for common SLT performance issues.
12. Can SLT tables be partitioned?
See KBA 2209687 - SLT HANA target table Source Table Has More Than 2 Billion Records for table partitioning.
Reactively you can manually repartition SLT logging tables with HASH on column IUUC_SEQUENCE. See SAP Note 2044468 for more information about SAP HANA partitioning.