BTP & Integrationadvanced

BTP Integration Suite Part 8: Hybrid Connectivity and Principal Propagation

Key takeaway

Connect Cloud Integration to on-premise systems: receiver adapters with proxy type On-Premise via Cloud Connector, location IDs, principal propagation of the calling user to S/4HANA, technical users for batch flows, and troubleshooting hybrid calls.

Explanation

📌 KEY POINTS
✅ Receiver adapters (HTTP, OData, SOAP, IDoc, RFC) can use proxy type On-Premise to reach systems via Cloud Connector.
✅ Use virtual hosts from Cloud Connector and location IDs when several connectors exist.
✅ Principal propagation forwards the sender's user to the back end (requires full trust chain).
✅ Technical users suit system-to-system and batch integrations.
⚠️ Mixing principal propagation with asynchronous processing (JMS) loses user context — user propagation needs synchronous flows.

━━━━━━━━━━━━━━━━━━━━
▶ WHERE WE ARE
Part 7 covered operations. Now hybrid connectivity.

━━━━━━━━━━━━━━━━━━━━
▶ 1. ON-PREMISE PROXY

Adapter settings; virtual host.

━━━━━━━━━━━━━━━━━━━━
▶ 2. LOCATION ID

Multiple connectors.

━━━━━━━━━━━━━━━━━━━━
▶ 3. PRINCIPAL PROPAGATION

Sender user → iFlow → SCC → back end.

━━━━━━━━━━━━━━━━━━━━
▶ 4. TECHNICAL USERS

Batch, async, system flows.

━━━━━━━━━━━━━━━━━━━━
▶ 5. TROUBLESHOOTING

Connectivity test tool, SCC logs, back-end logs.

━━━━━━━━━━━━━━━━━━━━
▶ STEP BY STEP

Expose the back end in Cloud Connector.
Configure receiver with On-Premise proxy.
Test connectivity, then run the flow.

✅ CHECKPOINT: connectivity test and iFlow both succeed.

Code example

ABAP Code

===== RECEIVER (OData) =====Address: http://s4h-virtual:443/sap/opu/odata/sap/API_SALES_ORDER_SRVProxy Type: On-Premise | Location ID: EU_DC1Authentication: Principal Propagation (sync) or Basic/Client Certificate (technical) ===== TROUBLESHOOTING =====Monitor → Connectivity Tests → Cloud Connector (location ID) → OK?SCC audit/trace → resource exposed? → back-end logs (auth)

Real project scenario

A BTP application reached S/4 through Cloud Connector, but the iFlow version failed with 'no route to host'. The iFlow used the real hostname instead of the virtual host. Switching to the virtual host fixed it.

Common mistakes

Real hostnames.
Missing location ID.
PP in async flows.
Skipping connectivity tests.
Overexposed SCC resources.

Best practices

Virtual hosts.
Location IDs.
PP only sync.
Test connectivity first.
Minimal resources.

Interview angle

Questions: "How does CPI reach on-premise?", "When use principal propagation?", "How do you troubleshoot hybrid calls?"
Strong answer: on-prem proxy, location ID, PP vs technical, troubleshooting.

Practice this lesson

Quick check

1. A BTP app reaches S/4 through Cloud Connector, but the iFlow fails with 'no route to host'. What is the likely cause?

2. Why must principal propagation be used in synchronous rather than asynchronous (JMS) flows?

3. What should you run before debugging a failing on-premise receiver in an iFlow?

Interview questions

1. An SAP Cloud Integration iFlow works in DEV but fails after transport to TEST. How would you troubleshoot it?

Answer it in your own words first, then compare.

2. iFlows must call S/4HANA on-premise, some with user context and some as batch jobs. How do you design hybrid connectivity?