Introduction

This blog shares our experience of upgrading a 3-tier NetWeaver Gateway landscape, pointing out the challenges we faced and how we were able to solve them.

Source Landscape

Existing 3-tier landscape with NetWeaver Gateway 2.00 SP 07 (NetWeaver 7.31 SP 09) in a central hub deployment model. Applications are connecting to a CRM 7.0 EHP1 system with NetWeaver Gateway 2.00 SP 07 backend components.

Target Landscape

Existing 3-tier landscape with SAP Gateway 7.40 SP 13 in a central hub deployment model. No changes to backend systems.

Upgrade Strategy

Execute a in-place upgrade. Start with sandbox systems, which are recent copies of respective production systems.

Initial Plan

According to SAP note 1830198 systems can be independently upgraded, upgrading Gateway doesn't require one to upgrade the backend components of the connected backend systems, assuming sufficient SP levels exist both in the Gateway and the backend systems. In our case we met the SP level requirements. The plan was not to upgrade the backend components.

Challenges

As soon as we had upgraded sandbox, we realized that our existing Gateway services didn't work anymore. More specifically, none of the services leveraging filter functionality worked. In addition there were issues with currencies that used to work that no longer worked.

Troubleshooting

Debugging the filter problem we found out that passing filter values got broken by the upgrade, values were being truncated. Looking into it in detail, we found SAP note 2205402 which we applied on both the Gateway system as well as the backend system, as instructed by the SAP note. This however wasn't sufficient. Since the corrections are partly contained in 740/13, we had to also implement SAP notes 2232883 and 2241188 on the Gateway system. Even that wasn't sufficient, we had to also implement SAP note 2245413 in the backend system.

Applying the SAP notes fixed the issues with filter functionality. The issue with currencies is explained in SAP note 2028852. We chose to change the applications in order to avoid the decimal problems described in the SAP note.

New Plan

In order to apply the SAP notes required to fix the issues with filtering, we had to also update the backend components to 2.00 SP 11. The new plan is to execute the in-place upgrade of NetWeaver Gateway and update the backend components.

Conclusion

I'm sure breaking compatibility or interoperability wasn't on SAP's radar but it happened. I have contacted SAP Gateway Product Management but I haven't yet been provided with an official explanation. In our case a simple technical upgrade of NetWeaver Gateway turned into a full-fledged upgrade project.

Takeaways

Take everything with a grain of salt, even official information can't be trusted. Test and validate everything yourself, preferably in a sandbox environment.

We are currently executing the new plan in our development landscape. I will update this blog should we run into other issues.