Configuring Zero Copy Connector for ERP to use SAP Load Balancing

[Enevoldsen]

Why This Matters

Most production SAP systems run on multiple application server instances. If you configure Zero Copy Connector for ERP to connect directly to a single application server, you lose resilience: that server goes down for maintenance, patching, or failover, and your Zero Copy Connector for ERP connection goes with it. You also bypass SAP's built-in workload distribution, which means your connector traffic can land disproportionately on one server.

SAP's native solution to this is logon load balancing via the SAP Message Server. Instead of pointing a JCo connection at a specific application server host, you point it at the message server, specify a logon group, and SAP takes care of routing each connection to the best available application server instance at the time of the connection request.

Zero Copy Connector for ERP supports this natively in the RFC connection configuration. This article walks through exactly how to set it up.

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Two Connection Modes: Direct vs Load-Balanced

When you configure an RFC connection for Zero Copy Connector for ERP, you are working with SAP JCo under the hood. JCo supports two connection modes:

Direct connection: Points at a specific SAP application server host and system number. Simple to set up, but ties every connection to a single server. Suitable for dev/sandbox environments. Not recommended for production.

Load-balanced connection: Points at the SAP Message Server. The message server maintains a list of active application server instances and their current load, and assigns each new connection to the most available instance. The logon group lets you scope which set of application servers participates in the balancing.

For production Zero Copy Connector for ERP implementations, load-balanced connection is the right choice.

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Prerequisites

Before you start, confirm the following with your SAP Basis team:

• The SAP Message Server hostname and port (commonly port 3600, or sapms<SID> as a logical name)
• The SAP System ID (SID): a three-character identifier for the ABAP system (for example, PRD for your production system)
• The logon group name: the named group of application servers Zero Copy Connector for ERP should connect to. If your Basis team has not defined a specific group, the default is SPACE (a single space character)
• A service-type SAP user account with the required RFC authorizations (see the SAP Authorization Requirements section at the end of this article)
• A ServiceNow MID Server installed in your network, with network-level access to the SAP Message Server port and the application server ports (3200 + system number, or as configured)
• The SAP JCo files (sapjco3.jar and either sapjco3.dll for Windows or libsapjco3.so for Linux) loaded onto the MID Server via All > MID Server > JAR Files

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Step-by-Step Configuration

Step 1: Open the RFC Connection Alias

Navigate to All > Connections & Credentials > Connection & Credential Aliases.

Search for and open the alias with ID sn_erp_integration.ERP_Canvas_RFC. This is the RFC alias that Zero Copy Connector for ERP uses for all SAP JCo-based connectivity.

Step 2: Create a New Connection and Credential

In the Related Links section of the alias record, select Create New Connection & Credential. This opens the connection configuration modal.

Step 3: Fill in the Connection Information

This is where direct and load-balanced configurations diverge. For a load-balanced connection, fill in the fields as follows:

Field	What to enter	Notes
Connection Name	A descriptive label (e.g., "PRD RFC Load Balanced")	Used to identify this connection in Zero Copy Connector for ERP system records
Host name or IP Address	Hostname or IP of the SAP Message Server	This is the message server host, not an application server
Login Language	Two-character language code (e.g., EN)
SAP Client	Your SAP client number (e.g., 100)
SAP System Number	Leave blank	System number is for direct connections only. Do not enter a value here for load-balanced connections.
Load Balancing: SAP Message Server Port	Port number or logical name of the message server	Commonly 3600, or sapms<SID> (e.g., sapmsS4P)
Load Balancing: SAP R3 Name	Three-character SAP System ID (SID)	Example: PRD, S4P, ERP
Load Balancing: SAP Load Balancing Group	Name of the logon group	Example: PUBLIC, SPACE, or a custom group defined by your Basis team

Common mistake: Setting a value in the SAP System Number field alongside the load balancing fields. System Number is only used in direct (non-load-balanced) connections. Leave it blank.

Step 4: Fill in the Credential Information

Below the connection fields, complete the credential section:

Field	What to enter
Credential Name	A descriptive label for this credential set
User Name	The SAP service user account username
Password	The SAP service user account password

Step 5: Assign to MID Server and Save

Confirm the connection is routed through your MID Server. If the MID Server is not already configured for Zero Copy Connector for ERP:

1. Navigate to All > MID Server > Servers and open your MID Server record.
2. On the Supported applications tab, add Zero Copy Connector for ERP.
3. On the Capabilities tab, add Zero Copy Connector for ERP alongside ALL.
4. Navigate to All > User Administration > Users, find the mid_user account, and assign the role sn_erp_integration.erp_mid_server.

Once done, save the connection record.

Step 6: Register the Connection on the Zero Copy Connector for ERP System Record

Navigate to All > Zero Copy Connector for ERP > Zero Copy Connector for ERP Home.

Open the ERP systems list (select the systems icon in the side panel) and open or create the system record for your SAP environment. In the Connection field, select the load-balanced connection you just created. Save the record.

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Validating the Connection

Once configured, confirm the connection is working before relying on it in any workflow or model execution.

1. Navigate to All > Workflow Studio.
2. On the home page, select Actions.
3. Filter the Name column for contains and type heartbeat, then select Apply.
4. Open HeartBeat and select Test.
5. Select your SAP system and select Run Test.
6. When the test completes, select the link to view the action execution details.
7. Confirm that isAlive is true in the output.

If isAlive is false, the most common causes are:

• The MID Server cannot reach the message server port (firewall or network routing issue)
• The SAP System ID (R3 Name) is incorrect
• The logon group name has a typo or does not exist (ask Basis to confirm it via transaction SMLG)
• The SAP service user does not have the RFCPING function module authorization
• The JCo JAR files are not correctly installed on the MID Server

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SAP Authorization Requirements

The SAP service user you configure needs the following RFC authorizations. Your Basis team will set these up.

For development instances (required for model discovery and metadata retrieval):

• S_RFC with Activity 16 (Execute) for: RFCPING, BAPI_MONITOR_GETLIST, RFC_METADATA_GET, RFC_GET_FUNCTION_INTERFACE, RFC_READ_TABLE, DDIF_FIELDINFO_GET
• S_TABU_NAM with Activity 03 (Display) for the metadata tables: DD01L, DD02L, DD02T, DD03L, DD04L, DD04T, DD12L, DD17S, DD40L
• S_DEVELOP with Activity 03 (Display)

For production and test instances:

• S_RFC with Activity 16 (Execute) for: RFCPING, BAPI_TRANSACTION_COMMIT, BAPI_TRANSACTION_ROLLBACK, RFC_METADATA_GET, RFC_GET_FUNCTION_INTERFACE, RFC_READ_TABLE
• S_TABU_NAM with Activity 03 (Display) for the specific tables used in your ZCC models

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Summary

Switching from a direct application server connection to load-balanced connection in Zero Copy Connector for ERP is a small configuration change with a meaningful operational benefit. Production SAP landscapes run on multiple application servers for a reason: your Zero Copy Connector for ERP connection should take advantage of the same resiliency and workload distribution that every other SAP client in your landscape uses.

The key distinction to remember is that load-balanced connections use three specific fields (Message Server Port, R3 Name/SID, and Logon Group) and leave the SAP System Number field blank. Direct connections do the opposite. Get that right and the rest of the configuration follows the same steps as any other Zero Copy Connector for ERP RFC connection.