Dual stack to Single stack migration

[Former Member]

Hi Experts,

We have our BI landscape with usage types BI ABAP and BI Java. We also use an integrated Enterprise portal for BI.

This setup is currently as a dual stack installation with both ABAP and JAVA stacks installed together.

However, the latest recommendations from SAP is to install them as a single stack installation.

SAP mentions that dual stack installations are still supported but it is recommended to be on single stack for performance reasons.

Currently we face performance issues in the BI Java area to a large extent and are looking at splitting the stacks as an option.

Has anyone performed this migration from Dual stack to Single stack installation ?

Is there a supported procedure from SAP for this migration.

Thanx to provide insights into this topic.

Thanx & Regards

Mahadevan

SAP Basis

[Former Member]

Hi,

Any strong reason for this deicsion.

When you install Dual stack All the Dual functionality will be hard corded with SAP(like Database and ABAP programs,BASIS roles & Automated connectivity).

You can not split Dual stack with sAP. You would get total inconsistency in the system.

There are some third party softwares, but not give you the perfect result.

You may get more information from the below tag,

Regards

Nagaraju

[Former Member]

Hi,

This is strange!! Do you mean migration to only-java installation?

check out following link

https://websmp208.sap-ag.de/instguides

Manoj

[Former Member]

Hi Manoj,

I know where installation guides can be accessed. Thanx for that.

If you look at the latest installation guide for SAP BI 7.0 EHP1 you will find that it is recommended to install BI ABAP and BI Java as two single stack installations with probably 2 different SIDs and if necessary 2 different databases.(although MCOD is also supported in some cases).

Now, if we have to migrate from the current dual stack to split stack what is the procedure.

I found one thread open with this question but no answers.

Regards

Mahadevan

[Former Member]

Hi Mahadevan,

I am one of the people who works on landscape recommendations. While it is true that, going forward, we no longer recommend installing dual stack systems in general cases, we have also said that there is no need to change existing systems. Are you experiencing any problems with your current setup?

It is technically possible to split a dual stack system, but there are no standard tools to do so. That is, it would be a project-based solution. And I am just talking about splitting the data into another SID. It is not possible to remove a Java add-in.

Best Regards,

Matt

[Former Member]

Thanx a lot Matt,

That helps.

In our BI landscape, we currently have users using BEX front-end as well as Java based queries thru EP.

While the BEX users do not face much trouble in terms of performance the Java performance has been very much unstable.

Since the recommendation from SAP for new installations is to go with 2 split stacks we wanted to analyze whether splitting the stacks would help in resolving our performance issues.

Any white paper or pointers on what all stuff to be considered before splitting the stacks(particularly wrt BI) would really help us proceed in this direction.

Looking forward to your inputs.

Thanx & Regards

Mahadevan

[Former Member]

Hi,

>Are you experiencing any problems with your current setup?

We are also thinking about spitting our dual stack systems. We already had a lot of troubles when applying Java support packages. On test (hopefully) we had to restore the database.

It means that a problem on the java stack destroyed the abap system.

We are afraid of getting this situation on a production system.

It may be too late for our BI systems but for our CRM 2007 systems, also in dual stack, J2EE is still not yet used. If the need for a J2EE application arrives, I think I will install a new J2EE single stack system.

One more time, my personnal opinion stays the same on this matter : systems needing both stacks were a big architectural error. The TCO is increased a lot and the realiability is way down...

Regards,

Olivier

[Former Member]

@Mahadevan

>the Java performance has been very much unstable.

Unstable in terms of what? Splitting the ABAP and Java installations will not necessarily solve any stability problems, especially if you keep the new Java on the same server.

>Any white paper or pointers on what all stuff to be considered before splitting the stacks(particularly wrt BI) would really help us proceed in this direction.

Like I said, this is a project solution. I am not aware of any white papers. In theory, it would involve identifiying all the data and configuration that belongs to this logical system, and re-implementing it in a new system. Perhaps the System Landscape Optimization group has some ideas (http://service.sap.com/slo).

@Olivier

>It means that a problem on the java stack destroyed the abap system.

What was the problem? Is there a customer message?

> If the need for a J2EE application arrives, I think I will install a new J2EE single stack system.

This is what we recommend.

>One more time, my personnal opinion stays the same on this matter : systems needing both stacks were a big architectural error. The TCO is increased a lot and the realiability is way down...

I was just wondering if you thought that, perhaps, SAP came to the same conclusion? We originally thought that there would be a TCO savings with dual stack systems, hence our original recommendation. In general, field experience has proven otherwise, but there are certainly very experienced admin's who prefer dual stacks.

Best Regards,

Matt

[Former Member]

Hi Matt,

>What was the problem? Is there a customer message?

No, because the problem was mainly a human error from our part. What I don't like is that an error when working on the java stack can potentially destroy the abap stack. I don't want this risk on my production systems !

>I was just wondering if you thought that, perhaps, SAP came to the same conclusion? We originally >thought that there would be a TCO savings with dual stack systems, hence our original >recommendation. In general, field experience has proven otherwise, but there are certainly very >experienced admin's who prefer dual stacks.

Yes, I know that and I recognise that SAP has been honest with this. But we have the feeling to have been guinea pigs for SAP. We are now stuck with architectures that we feel are bad.

SAP says now : Sorry Guys that you just listened to our advices, you should not have...

Separate stacks or dual stack, I just don't see why a product should need both abap and java.

It adds a level of complexity which is just unnecessary : think about SSO between java and abap in a PI system : what a nightmare !

I don't see anything programmed in java that could not be programmed in abap.

The teacher at my last SAP PI class told us to never change the passwords of the technical users. One of his main job as a contractor is to repair the PI systems where the basis team dared to change the passwords...

It seems that the choice at SAP to program a new module/application in abap or java comes randomly from the next developement team to be ready.

PS: Don't be afraid by my rants : I still sleep very well and I still enjoy my job as a basis admin !

Regards,

Olivier

[Former Member]

Hi Olivier,

I never fear your rants! Rather, just the opposite. People like me use them as feedback and ammunition in our conversations with development..so, in that respect, I appreciate them. Let's just say that your exact points came up in internal conversations (and still do).

Best Regards,

Matt

[Former Member]

Hi Matt,

It's a pleasure to have interesting conversations with you !

Olivier

[Former Member]

Hi Matt,

Apologies for not having replied for few days.

When I mention Java is unstable, I meant that performance of Java stack is pathetic.

The current solution from SAP from a customer message was to restart the Java stack whenever we run into severe performance degradation...and we do this almost every weekend

There is an ongoing data center consolidation project going on and as part of it, the BI landscape is also planned to be moved to new servers using backup/restore.

During this move, we have already planned to have ABAP CI+DB in one box and have the Java CI in a separate box(appln. server) ofcourse with the same DB.

I am not sure if this works similar to what you could achieve with splitting of stacks.

We'll have our fingers crossed and hope that things will improve.

Best Regards

Mahadevan

[Former Member]

Hi Mahadevan,

I come from an ABAP systems background myself, so you're not going to get much discussion from me about Java tuning/performance ;-)...

Your setup should work -- ABAP CI one server, Java CI second server, same DB -- using the MCOD installation option.

Best Regards,

Matt

[Former Member]

dear matt,

i read this interresting article about splitting dual stack to single stack, and i would know if to this day there exists an official procedure to split up a dualstack installation especially regarding nw-bi-70, because we are in the middle of a migration project and our sap consultant recommanded this (to our customer).

if anyone has a solution that works don't hesitate to contact me!

best regards

julius

Edited by: Julius-Peter Vanecek on Nov 19, 2009 4:36 PM

[Former Member]

Hi Julius,

No, there is not yet an "official" procedure to split a dual stack system. As I mentioned above, it is still a project based solution (due to customer specific data).

Rereading this (it's been a while) I do see a factual error I made. You can uninstall Java from a dual stack system using sapinst. However, this doesn't take care of the data issue mentioned.

Best Regards,

Matt

[Former Member]

Mi Matt,

thx for the fast response!!

ok, i understand, you suggest to drop the j2ee instance on the dualstack installation with sapinst and install it new als singelstack with sapinst?

but is there any possibility to do this with an export/import procedure without dropping the dualstack j2ee instance. so that i can import the java content from the dual-stack installation in the singel-stack installation.

very best regards

julius

[Former Member]

Hi Julius,

>you suggest to drop the j2ee instance on the dualstack installation with sapinst and install it new als singelstack with sapinst?

Yes.

>is there any possibility to do this with an export/import procedure without dropping the dualstack j2ee instance. so that i can import the java content from the dual-stack installation in the singel-stack installation.

This is what I'm saying: there is no "official" procedure for the data. The data and configuration are customer specific and you will have to determine how to migrate the data to the single stack.

Best Regards,

Matt

[Former Member]

hi mat,

first of all, thx a lot.

that´s the point, how to migrate the data and configuration to the single stack!

is there an unofficial howto guide or a todo list, or do you know someone how made this.

br&have a nice weeeekend

julius

update:

there is an oss-note regarding this topic:

Note-1181025 NW70EHP1 install BI Dual Stack System (Workaround)

Edited by: Julius-Peter Vanecek on Nov 24, 2009 9:27 AM