HANA SLT

SLT stands for SAP Landscape Transformation Replication Server (SLT) running on the NetWeaver Platform.

SAP Landscape Transformation Replication Server is a replication technology that provides

data from ABAP and non-ABAP systems to an SAP HANA environment.

Task:

   1. Its replicate data between SAP system and non-SAP System with different database.

   2. Its replicate data in real time as well as non-real time. i.e. in interval

   3. Replicate the same table of different SAP systems to one HANA system. This is possible    even into one table.

   4. Transfer data between SAP HANA systems: starting with SAP LT Replication Server 2.0 SP3 (DMIS 2011 SP3) and HANA SP05

   5. Its work for both non Unicode as well as Unicode but target Hana system should be Unicode. It is triggered based replication: A technique for replicating data where an initial load is first performed that loads data from the source to the target system, and a replication phase begins whereby only changes to the source database (recorded by databases triggers) are replicated to the target database, thereby facilitating data replication in real-time.

Architecture:

The source system tracks database changes by using database triggers. It records information about changes in the logging tables. Read modules (located on the ABAP source system) transfer the data from the source system to the SAP LT Replication Server. The relevant data is read from the application tables.

Installation:

Planning

   1.The SAP LT Replication Server can either be installed within the source system or in a separate SAP system in ABAP System. For non-ABAP/non SAP system it should be on separate location.

   2.This decide based on background process available and CPU cycles

   3.The SAP LT Replication Server system must be a Unicode system 

   4.Ensure that database performance is good. Poor database performance can result in poor SAP LT Replication Server performance.

SAP LT Replication Server is a Separate System for ABAP

Prerequisite

   1.SAP LT Replication Server is shipped in an add-on call DMIS_*.

   2.Install the Add-on as per below

SAP NetWeaver Version	ABAP Source System	SAP LT Replication Server System
4.6C	DMIS_2010	N/A
620, 640, 700, 701	DMIS_2011	N/A
702 → 740	DMIS_2011	DMIS_2011

   3.The system running the SAP LT Replication Server must be an ABAP system with at least SAP NetWeaver 7.02 (Basis support package 8), with an ABAP stack using SAP Kernel 7.20 (64BIT Unicode) patch level 110 or higher

   4.If you want to use a new SAP LT Replication Server system, you install a new SAP NetWeaver instance.

   5.Read SAP Note 1577441, and check whether your SAP Basis and support pack version are supported

   6.Read SAP Note 1597627 for information about how to setup the secondary database connection and to check required SAP kernel prerequisites.

   7.As a minimum requirement, an SAP LT Replication Server should provide the following hardware configuration:

File system: 100 GB RAM: 8-10 GB, CPU: 2-4 cores, Minimum number of background jobs: 10, Network: 1GB/sec or better

Running Installation:

   1.Download DMIS from the following path: Installations and Upgrades → A - Z Index → L → SAP LT Replication Server → SAP LT Replication Server 2.0

   2.Install Netweaver and database as per your need. 

   3.From Saint installed the add-ons on the NW system.

Post Installation Activities

   1.Enable Web Dynpro SAP LT Replication Server services from SICF

   2.Create an RFC connection to the source system. A user is required in the SAP HANA In-Memory Database so that replication data can be stored

Configuration:

  1.Create RFC Connection in SLT system which is used in Configuration. Provide details of Source system from where data will be pulled. Note here don’t use DDIC user in RFC.

Since DMIS 2010 SP9 / DMIS 2011 SP4 two new roles for the user in the SLT System have been created. Role SAP_IUUC_REPL_ADMIN is required to create, change or display configurations. Role SAP_IUUC_REPL_DISPLAY can be used if a user should be able to see the existing configuration and their status but is not allowed to change any settings or create a new configuration.

For non- ABAP sources, you need to create database user(s) with appropriate authorizations in advance and establish the database connection by using transaction DBCO in the SAP LT Replication Server.

  2.The role SAP_IUUC_REPL_REMOTE must be present in source ABAP system, if not we can generate it as below:

        1.Execute transaction PFCG.

        2.In the role field, enter the role SAP_IUUC_REPL_REMOTE.

        3.Choose the Change Role pushbutton.

        4.On the Authorizations tab page, choose the Change Authorization Data pushbutton.

        5.The system displays the Change Role: Authorizations screen. Choose the Generate

        6.Return to the Authorizations tab page; this tab page should now have a green light.

        7.In the User tab page, choose the User Comparison pushbutton.

        8.The system displays the Compare Role User Master Record screen. Complete 

        9.The User tab page should now also have a green light.

  3.In the Configuration & Monitoring Dashboard (transaction LTR), you can define a new configuration

  4.In the second step, specify your source system. For an ABAP based system we connect via RFC connection, for a non-ABAP system we connection via a 2nd DB Connection (SLT supports only SAP supported DB ‘s).

  5.In the third step, you specify all relevant information about the target system.

  6.In the fourth step, we specify the transfer settings.

  7.In the fifth step you review all your settings and start the creation process of the configuration 

  8.If table IUUC_TAB_ALLOWED is empty, then every configuration in every SAP LT Replication Server system has unrestricted access to all tables in the source system.

Administration:

  1.You can open the configuration to monitor the triggers from LTR T-code

  2.Start/stop/Replication

         Start Load: Starts an initial load of replication data from the source system. The procedure is a one-time event. After it is completed, further changes to the source system database will not be replicated. 

For the initial load procedure, neither database triggers nor logging tables are created in the source system.

Run Tcode LTRC and select Mass Transfer ID then go to data provisioning select table and select load method.

         Start Replication: - Combines an initial load procedure and the subsequent replication procedure (real time or scheduled). 

Before the initial load procedure will start, database trigger and related logging table are created for each table in the source system as well as in SLT replication server.

                If you use start replication it will create the table in HANA system

                It will create the triggers for each record insert, update, delete

                It will create the logging tables

                Whenever records insert or delete or update it will trigger and trigger update material number, timestamp in the logging tables

Ex table – MARA

Logging table for MARA: Logging table will create based on the primary key of MARA table

In MARA table MADNT and MATNR both are initial values

Logging table for MARA /1CADMC/00001607

         Stop Load/Replication: Stops any current load or replication process of a table. 

The stop function will remove the database trigger and related logging tables completely. Only use this function if you do want to continue a selected table otherwise you must initially load the table again to ensure data consistency.

         Suspend: Pauses a table from a running replication. The database trigger will not be deleted from the source system. The recording of changes will continue and related information is stored in the related logging tables in the source system. 

If you suspend tables for a long time the size of logging tables may increase and adjust the table space if required.

         Resume: Restarts the application for a suspended table. The previous suspended replication will be resumed (no new initial load required).

Jobs in SLT

Master job/Monitoring Job /1LT/IUC_REP_MSTR: It start after SLT system start by system event SAP_SYSTEM_START. This event (SAP_SYSTEM_START) which ensures that the master job is started automatically after a restart of the SLT system. 

Every 5 seconds, the monitoring job (/1LT/IUC_REP_MSTR) checks in the SAP HANA system whether there are new tasks and, if so, the /1LT/IUC_REP_MSTR triggers the jobs /1LT/IUC_REP_CNTR_<mtid>.

Note: Every day at midnight, the monitoring job and related data load jobs are automatically stopped and restarted immediately. (- but not the migration object definition or access plan calculation jobs –) This action has no negative impact on the ongoing data load and replication, it will simply resume immediately.

Master Controller Job /1LT/IUC_REP_CNTR_<mtid>

This job is scheduled on demand and is responsible for:

   1.Creating database triggers and logging table in the source system

   2.Creating synonyms

   3.Writing new entries in admin tables in SLT server when a new table is loaded/replicated

Data Load Job 1LT/IUC_LOAD_MT_<mtid>_nnn

This job should always be active. If the job does not complete successfully, the master controller job restarts it. This job is responsible for:

   1.Loading data (load)

   2.Replicating data (replication)

   3.Changing status flag for entries in control tables in the SAP LT Replication Server

Migration Object Definition Job /1LT/IUC_DEF_COBJ_<mtid>

This job defines the migration object of a specific table

Access Plan Calculation Job /1LT/IUC_CALC_ACP_<mtid>_n

This job calculates the access plan of a specific table

Relationship between the number of data transfer jobs and the number of available background work process.

Each job occupies 1 background work process in the SAP LT Replication Server system. 

Single mass transfer ID (MT_ID) requires at least 4 background jobs to be available:

   • One monitoring job (master job)

   • One master controller job

   • At least one data load job

   • One additional job either for the migration objects definition, access plan calculation or to change configuration settings in the Configuration & Monitoring Dashboard.

Difference between LTR and LTRC: for security reason LTR uses SAP NetWeaver Business Client 3.5 or 4.0 and if we are using browser instead of Business client the browser will not have logout option and closing browser will not logout user from system.   In another side Business Client supports a logout for all Web Dynpro windows. In order to use the SAP NetWeaver Business Client, the relevant user must have the role SAP_IUUC_REPL_NWBC assigned to them. 

So main difference, to access LTR we need SAP_IUUC_REPL_NWBC role while LTRC don’t need any specific role like NWBC. 

LTR: Configuration & Monitoring Dashboard

Provides capabilities to initially create, manage, and monitor configuration and related settings. After the creation of a configuration, you can:

   • Use functions such as stop/restart the configuration master job.

   • Change configuration settings such as the number of total jobs (and number of total jobs for initial load).

   • Monitor the trigger and replication status, including detailed throughput information for the data replication.

LTRS: Advanced Replication Settings allows you to define and change various table settings for a configuration such as:

   • Partitioning and structure changes for target tables in SAP HANA

   • Table-specific transformation and filter rules 

   • Adjusting the number of jobs (and reading type) to accelerate the load/replication process

Mass Transfer ID and Schema GUID

When creating a new configuration in the SAP LT Replication Server, a schema GUID and a mass transfer ID (MT_ID) is automatically created and assigned to the configuration.