Switch over between two SAP PI systems for downtime minimization

[former_member285279]

Hello Colleagues,

with our interfaces over our SAP PI 7.31 (ABAP/Java) system we assume we will run in a 7x24 h runtime scenario in the future.

Regarding Business Continuity we have to think about solutions which help us to handle downtimes greater than 15 min. regarding Support Package upgrade, Kernel update, EHP, etc.

The first idea is to implement a second equal SAP PI productive system in parallel to the existing one.

On the sender side a switch over implementation like WebDispatcher, Load Balancer, etc.

For maintenance all Interface traffic can run over PI Nr. 1 and PI Nr. 2 can be updated.

Afterward all interfaces will switched to PI Nr. 2 and PI Nr. 1 can go in maintenance.

Could be this as suitable solution for SAP PI Business Continuity or do you know better solutions?

Many thanks in advance!

Regards,

Jochen

[Former Member · Accepted solution]

Hi Jochen,

Your first idea is technically working, but has several challenges and restrictions. Maintenance of SLD is one prominent example.

Works for synchronous/stateless scenarios as Benhard mentions. The main restrictions are related to asynchronous messaging and BPM scenarios. Processes, messages, error situations and acknowledgements may be on different instances and should be finished first, before switching back the scenario. Not to talk about monitoring.

We did and recommended your first idea in the past before nZDM for PI was available, but meanwhile nZDM is the better and recommended way.

Best regards,

Holger

[former_member285279 · Accepted solution]

Hello Bernhard, Hello Holger,

many thanks for reply and providing these valuable information's.

The nZDM Concept is already known to me but it doesn’t answer all our questions.

Please let me explain a little more in detail.

Not currently but in the near future we assume some new interface over our SAP PI System will come with the requirement max. downtime lower thank 10 to 15 min. only allowed.

To be prepared regarding this possible scenario, we start thinking about possible different solutions.

First step was the nZDM Concept, of course. But it didn’t meet all our requirements regarding interface downtime.

Some points are:

• possible min. downtime is 30 min. and thus is over our requirements for interfaces
• only for Update (and planed for Upgrade) the SAP PI application
• all operating system and database related maintenance tasks are not covered by nZDM
• all Hardware (Server, Storage, etc.) as well not covered by nZDM

Among others, because of these facts we start thinking about a second equal SAP PI system beside to existing productive one.

Than line 1 will take over the whole interface traffic and in the meantime the line 2 can go in maintenance. After finalizing the maintenance for SAP PI Nr. 2 we can switch the interface traffic to SAP PI Nr. 2 to get SAP PI Nr. 1 free for maintenance.

Regarding the topic “PI Federation” I found here in these documentation's several hints regarding this scenario (two SAP PI systems in an switch over scenario).

PI Federation – An Overview

among others  Page: 27

…

Business Continuity: Central PI integration Server with redundant Integration Server to be used in controlled switch over scenarios when upgrading or patching.

…

or

How to Fast-Switch Integration Scenarios between SAP PI Runtimes Part II: Web Dispatcher

But I didn’t found any further detail documentation's regarding this approach.

The solution should fit as well to our existing hardware infrastructure.

For production we use an IBM (AIX) failover-cluster switch between our both data center.

Regarding our hardware infrastructure prerequisites and downtime requirements, which solution(s) do you recommend? Is PI Federation still an option?

Many thanks in advance!

Regards,

Jochen

[Former Member · Accepted solution]

Hi Jochen,

To my knowledge there was no additional guides or updates from SAP side on this topic. As I was an author of the referred guides, I would be very interested on customer project based details. Challenges and solutions, what would help other customers with similar downtime request, too.

As said: Technically it was working, but you face the above named challenges. Therefore the recommended approach is nZDM.

Usually customers have only few scenarios which need lower downtime and maybe you limit the switch sceanrios to these.

Finally you have to balance effort and resrtrictions against the benefits.

Maybe we get some feedback and advices from others, too!

Comming back to to your question on info sources, I want to raw your attention to the up to date SAP PI/PO deployment recommendations: Deployment_Recommendation_SAP_NetWeaver_ProcessOrchestration slide 15 and following on benefits and consierations.

Best regards,

Holger

[former_member285279 · Accepted solution]

Hi Holger,

again thank you for providing these helpfully information's.

Now I have a clear understanding about the possibilities regarding Business Continuity for SAP PI. For our current Interface Processing over SAP is nZDM the right choice.

Maybe in the future we have to think about for additional own improvements.

It would be great, maybe for you too, if I can come back to you for additional direct discussions, work, etc. in the future.

Now we have to think about our next steps for improve our Business Continuity capabilities with nZDM as first step.

Best regards,

Jochen

[former_member182060]

Hi Jochen,

In general, this approach is possible if you use just and only use stateless PI adapters. However, this  prereq is not often met.

You should definetly consider to use the nZDM tool for PI to minimize your downtime. There is a How-To Guide available (SAP NetWeaver Process Integration and Near Zero Downtime Tool - An How-to Guide ), which describes the various PI landscape scenarios and explains how to use the nZDM tool for PI for which particular scenario accordingly. The nZDM tool for PI dual-stack is generally available and definetly supports PI 7.31.

Best, Bernhard