RFC setup for client copy

 In SAP Basis, Remote Client Copy (using transaction SCC9) relies on RFC (Remote Function Call) connections to transfer data between a source SAP system and a target SAP system. Local client copies (SCCL) do not require RFCs as the data transfer occurs within the same system.

Here's a detailed setup guide for RFC for client copy in SAP Basis:

1. Prerequisites for Remote Client Copy:

• Identical SAP Product and Release: Both the source and target SAP systems must have the same SAP product installed (e.g., SAP ECC, S/4HANA) and be on the same release version and support pack level. Mismatches can lead to inconsistencies and errors during the copy.
• Sufficient Disk Space: The target system must have enough disk space to accommodate the copied data. A general rule of thumb is at least twice the size of the source client, but a test run (discussed later) can provide a more accurate estimate.
• System Availability: It's highly recommended to perform client copies during periods of low system activity or scheduled downtime on both source and target systems to ensure data consistency and avoid performance issues. Lock all users in both the source and target clients before starting the copy.
• Client Creation (Target System): A new client must be created in the target system (using transaction SCC4) where the data will be copied.
• User SAP* in Target Client: After creating the new client, log in to it with the user SAP* and password pass. This user is critical for the initial setup and client copy process. Ensure the profile parameter login/no_automatic_user_sapstar is set to '0' to enable this.
• No Modifications During Copy: No functional changes or transports should be imported into either the source or target system during the client copy process.
• Timeouts: Adjust the rdisp/max_wprun_time parameter in both systems to a value greater than 1500 seconds (or higher, depending on the client size) to prevent work processes from timing out during the extensive data transfer.

2. RFC Setup Steps (SM59):

The RFC connection needs to be created in the target system, pointing to the source system and client.

1. Log on to the Target System: Log on to the target SAP system, specifically to the client where you want to perform the client copy (the newly created client or an existing one that will be overwritten). Use an administrative user like SAP* or a user with SAP_ALL authorization.
2. Go to Transaction SM59: Enter SM59 in the SAP command field and press Enter. This transaction is used to configure RFC destinations.
3. Create New RFC Destination:
   • Click on the "Create" button (or F8).
   • Enter the following details:
     • RFC Destination: Choose a meaningful name, e.g., SIDCLNT<SourceClient> (e.g., PRDCLNT300 if your source system is PRD and client is 300).
     • Connection Type: Select "3" (ABAP Connections).
     • Description: Provide a clear description, e.g., "RFC to Source System PRD Client 300 for Client Copy."
   • Press Enter or click the green checkmark.
4. Configure Technical Settings (Target Host Tab):
   • Target Host: Enter the hostname or IP address of the source SAP system.
   • System Number: Enter the instance number of the source SAP system.
   • Gateway Host: This is usually the same as the Target Host.
   • Gateway Service: sapgwXX where XX is the instance number of the source SAP system (e.g., sapgw00).
5. Configure Logon & Security Tab:
   • Language: Specify the logon language for the RFC connection (e.g., EN for English).
   • Client: Enter the source client number (e.g., 300). This is crucial as the RFC will connect to this specific client in the source system.
   • User: Create or use an existing RFC user in the source system specifically for client copy. This user must have significant authorizations, typically equivalent to SAP_ALL, or at least the authorization object S_RFC with ACTVT = 16 and RFC_NAME = *. It's best practice to create a dedicated user for this purpose and not use a dialog user.
   • Password: Enter the password for the RFC user in the source system.
   • Current User: Uncheck this if you are using a specific RFC user.
   • Trust Relationship: For increased security, you can configure a trusted RFC connection, which eliminates the need to store a password in the RFC destination. This is an advanced step and requires additional configuration.
6. MDMP & Unicode Tab:
   • Communication Type with Target System: Select "Unicode" if both systems are Unicode-enabled (which is the standard for modern SAP systems).
7. Save the RFC Destination: Click on the "Save" button.
8. Test the RFC Connection:
   • After saving, click on the "Connection Test" button. This tests the network connectivity and whether the RFC destination can reach the source system.
   • Next, click on the "Remote Logon" button. This tests if the RFC user can successfully log on to the specified client in the source system. Both tests should be successful. If there are errors, troubleshoot network issues, hostname resolution, firewall rules, or user authorizations in the source system.

3. Assign RFC Destination for Client Copy (FINB_TR_DEST or SCC9 Wizard):

• Transaction FINB_TR_DEST: In the target system, you might need to explicitly assign the RFC destination you created in SM59 to the source client using transaction FINB_TR_DEST. This transaction is used to maintain RFC destinations for cross-system activities.

  • Enter FINB_TR_DEST in the command field.
  • Create a new entry.
  • Specify the Source Client (e.g., 300) and the RFC Destination you just created (e.g., PRDCLNT300).
  • Save the entry.

• SCC9 Wizard (Recommended): When you start a remote client copy in SCC9, the system often guides you through a wizard that helps configure or select the RFC destination. This is often the most straightforward way to link the RFC to the client copy process.

4. Performing the Remote Client Copy (SCC9):

1. Log on to the Target System and Target Client: Again, log in to the target SAP system and the specific client where you want to copy the data.
2. Go to Transaction SCC9: Enter SCC9 in the SAP command field.
3. Select Copy Profile: Choose the appropriate copy profile based on your requirements (e.g., SAP_ALL for a complete client copy, SAP_CUST for customizing data only, etc.).
4. Enter Source Destination: In the "Source Destination" field, select the RFC destination you created (e.g., PRDCLNT300).
5. Test Run (Highly Recommended): Before performing the actual copy, always execute a "Test Run." This simulates the copy process and checks for any potential issues, like insufficient disk space, authorization problems, or repository differences, without actually transferring data. Review the test run logs carefully in SCC3.
6. Schedule as Background Job: For remote client copies, it is essential to schedule them as a background job due to the large volume of data and potential long running times.
   • Click on "Schedule as Background Job."
   • You can set the start time to "Immediately" or schedule it for a later time.
   • You can also specify parallel processes to speed up the copy, if your system resources allow.
7. Monitor the Client Copy: Use transaction SCC3 in the target system to monitor the progress and status of the client copy job. It will provide detailed logs and any errors encountered.

Important Considerations and Troubleshooting:

• Authorization Issues: The RFC user in the source system needs broad authorizations. If you encounter errors, verify the authorizations of the RFC user in the source system.
• Firewall: Ensure that firewalls between the source and target systems allow communication on the necessary SAP ports (typically 32xx, where xx is the instance number).
• Network Latency: High network latency between the source and target systems can significantly impact client copy performance.
• Repository Differences: While RFC client copy can handle some codepage conversions, significant data dictionary differences (e.g., custom tables or fields) between the source and target systems can cause issues. SAP Note 557132 discusses potential problems. If there are major repository differences, it's generally recommended to synchronize them via transports before the client copy.
• Logical System Name Conversion (BDLS): After a remote client copy, especially if you're copying from a productive system to a quality/development system, you'll likely need to perform a logical system name conversion using transaction BDLS in the target system. This updates logical system names in tables to reflect the new target environment.
• Post-Copy Activities: After a successful client copy, there are several post-copy activities to perform, such as regenerating screen containers (BUSP), adjusting number range buffers (SM56), and verifying integration models.

By following these steps, you can successfully set up an RFC connection and perform a remote client copy in your SAP landscape. Always remember to plan thoroughly, perform test runs, and review logs for a smooth and error-free process.