Setting Up Data Replicaton

The main transaction in SLT is LTRC, which opens the SAP Landscape Transformation Replication Server cockpit. The SLT cockpit displays all created configurations, their status (Active Running or Not Active Finished), the scenario, and the connection types to source and target systems. To start a guided procedure that leads you through the creation process, choose Create Configuration.

Each configuration should have a unique and descriptive name. However, this is not always possible, and so two configurations can have the same name. Instead, they are differentiated by an ID, which is called the mass transfer ID.

If you require specific authorizations for the configuration, you can define an authorization group and use it in the corresponding authorization object S_DMIS_SLT.

The following list provides additional information about replicating to SAP HANA:

• When you create a configuration, a schema and a user with the same name is created automatically in the SAP HANA system. You can also reuse an existing schema that was not created automatically by SLT. For example, you can use a schema that was not created automatically by SLT but that was created independently in the SAP HANA system.
• After the Specify Target System step, a dialog box appears and requests that you specify a user that is authorized to access the schema. This user must not have the same name as the schema. If you use lower-case letters in the configuration name, the schema name in the SAP HANA system will also contain lower-case letters.
• If you want to transfer data from two systems into the same database schema, or even table (N:1 scenario), you must give the configurations the same name.

You can choose from where the data is replicated, either by using an RFC connection or a database connection.

If your source system is an ABAP source system, you can specify whether multiple usage is allowed (1:N scenario), which is activated as default from DMIS 2011 SP13 onwards. This enables multiple configurations to replicate data from the same source system. In that case, all replication objects (logging tables, reader modules, and so on) are created differently to reflect this scenario.

It is possible to change a 1:1 configuration to a 1:N configuration, but this is not recommended. Inconsistencies might arise if part of the tables that were initially selected for replication in a 1:1 context are later switched to 1:N, or if the reverse occurs.

By selecting the Read from Single Client checkbox, data is read from the client specified in the RFC connection only. Data changes in other clients are not replicated. If you want to use 1:N and single client, single client needs to be active for all configurations with this source system, otherwise trigger creation will fail.

To specify the target of your configuration, you can again specify an RFC or database connection.

If you want to replicate data to a database, you can select the database system from the dropdown list.

The administration user is the SAP HANA database user, which is used for creating the target schema and roles. You must specify the user and the password of the administration user.

You must specify the host name of the target SAP HANA database, and you must also specify the port (30115) consisting of the instance number (01) and the logical port number (15).

If you are replicating data to SAP HANA and want to use an encrypted connection, the SAP Landscape Transformation Replication Server system must have a DBSL version of 7.22 or higher. In addition, the target SAP HANA system must be SPS7 or higher with encrypted connections enabled. For more information, see the SAP HANA security guide.

For more information about the database connection from the SLT server to the SAP HANA database, see SAP Note 2389173.

The image shows how to create a configuration for data transfer settings.

The data transfer settings are as follows:

If you want to use a different default reading type, you can define an initial load mode. The initial load modes are as follows:

• Resource optimized

  This mode uses reading type 3 for all tables. (If the source system is SAP on HANA or HANA DB directly, reading type 1 is used.)

• Performance optimized

  This is now the default mode. Use this mode if reading type 4 (for cluster tables) or 5 (for all other tables) is needed for all tables.

If you choose to configure a separate tablespace, you can provide this information. It is possible (but not essential) to store the source system logging tables in a separate table space. The system administrator decides whether to do this or not.

One advantage of having the logging tables in their own table space is that you can easily monitor the size of the log tables. Because each database system has its own method of providing this functionality, refer to your database documentation for this procedure. See also SAP Note 46272.

This is relevant for Central Finance scenarios only.

The job options are as follows:

• Number of Data Transfer Jobs

  This value specifies the number of data transfer jobs that run in this SAP Landscape Transformation Replication Server configuration to replicate the tables of the RFC connection to the SAP HANA system.

• Number of Initial Load Jobs

  This value specifies the maximum number of data transfer jobs that SLT is allowed to use for objects in the initial load.

  This number should be smaller than the overall number of data transfer jobs so that there are still jobs available for replication of other tables.

• Number of Calculation Jobs

  This value specifies the number of access plan calculation jobs that are allocated by this configuration.

In the replication options, you can select how data should be transferred for this configuration. You can choose between the following options:

• Real Time

  Data is transferred as soon as it is available in the source system.

• Scheduled by Interval

  SLT checks in a fixed interval (for example, every 15 minutes) to determine if new data is available in the source system. If so, SLT transfers the data.

• Scheduled by Time

  Every day, at a specific time, the logging tables in the source system are checked, and if new records are found, data is replicated.

• On Demand

  This is a legacy entry from the Central Finance scenario. It can be used as an advanced option where SLT is remote controlled via a function module.

• Activate Replication Logging

  If you choose this option, the replicated data entries are saved in the SAP Landscape Transformation Replication Server system for all tables in the configuration for a defined period of time. This means that if any data is missing in the target system, you can view it and replicate it again from the SAP Landscape Transformation Replication Server system to the target system. This is only available for non-ABAP target systems.

• Activate Reload Procedure that Retains Data in the Target System

  If a critical event occurs to a table or CDS view in the source system (such as a changed key field), then a new initial load of data is required. If you are replicating data to SAP HANA, you can use a reload procedure that minimizes the impact that this event has on the target system. If a critical event occurs to a source system table or CDS view (key field added, deleted, or modified), then SAP LT Replication Server can automatically start a new initial load and resume the replication process for the table or CDS view without any noticeable impact in the target system. To do this, SAP LT Replication Server creates two tables in the target system - a consumption table and a reload table. Both tables begin with the prefix /1LT/BG plus a numeric ID. One table contains changed data before the new initial load starts, and the other contains the data of the new initial load. After the initial load is finished, the second table takes over the role of the first table, and the first table is then dropped. This allows a new initial load to take place without any noticeable impact in the target system.

In the source system, archiving activities can result in the deletion of table records. However, you may not want these deletion operations to be executed in the target system. This field indicates whether you are using this option to prevent such changes to the target system for this configuration.

If you choose the Approval Required for All Data Provisioning Actions option, any action that you schedule for an object must be approved before the action can start. You can select this option on the Administration Data tab or when you create your configuration. On the Data Provisioning screen, you can schedule actions for objects. When you schedule an action for an object (for example Replication) the system adds the object to the list of objects on the Participating Objects tab. In the Current Phase column, the object will have the status Awaiting Approval. You can view the scheduled action for the object in the Details column. To approve the scheduled action for the object and start the action, choose Approve. To deny the scheduled action for the object and remove it from the list, choose Deny. The required authorization to approve actions is controlled by authorization object S_DMISIUCA. For more information, see the SAP Landscape Transformation Security guide at https://help.sap.com/sapslt.

As a last step, review the settings again before you create the configuration.

The Web Dynpro-based UI (transaction LTR) of SAP Landscape Transformation replication server 2.0 has a similar guided procedure to create configurations. For more information, see SAP Note 1972009.