Pros and Cons of a Distributed Oracle Database Environment

[Former Member]

Hi everyone,

I'm interested to know the pros and cons of running a SAP environment with a distributed database without HA being a consideration.

eg DB installed on RHEL - HP C-Class Blade, and CI installed on AIX - Power 570 server.

Obviously load/performance is a consideration however given the latest IBM Power series scale upwards vs sideways, I don't understand why they just wouldn't have the DB + CI installed in the same LPAR.

I've always been a fan of simplification and consolidation when it comes to SAP environments, however I know a few sites that have their DBs installed on different hosts ... why??

Please outline the pros and cons of running a distributed DB environment.

Regards

Shaun

[Former Member · Accepted solution]

Hi Shaun,

It depends your strategy. From minimizing administrative overhead point of view, you are correct. At the production sites, I choose to seperate DB and CI instances to the different host, because of the performance reasons. This is because, if the host is dedicated to the database system, the database will be able to use all the hardware resources for itself. On the other hand, running CI or another application server on the same host or logical partition with the database, may cause a resource contention between them.

On my test and QA systems, I choose to install CI and DB on the same host. Some of the productives are running on the same host also. But, some of the SAP installations we decided to run database system on a separated host for the performance and resource utilization reasons.

In summary, it will be better if the you are running on a large and high level of activity database, you should run the database system and the CI at the different LPAR or host.

Best regards,

Orkun Gedik

[Former Member · Accepted solution]

At the production sites, I choose to seperate DB and CI instances to the different host, because of the performance reasons. This is because, if the host is dedicated to the database system, the database will be able to use all the hardware resources for itself. On the other hand, running CI or another application server on the same host or logical partition with the database, may cause a resource contention between them.

Hi Orkun,

I agree that if your hardware is unable to scale upwards/vertically, then separating the DB and CI makes sense. But in the case of this customer an IBM Power 750 can scale vertically (eg I can add memory and CPU dynamically to the LPAR .. or just leave is uncapped), thus we can easily ensure that there would be no resource contention between the DB and CI.

Any other reasons why you would separate them?

Cheers

Shaun

[Former Member · Accepted solution]

Hi Shaun,

If you can configure a LPAR that can handle all the system requests, you can run both CI and DB instances on the same host. I don't see any technical problem, about it. But, at the same time you should take into account, system security and SPOF cases, as well.

Best regards,

Orkun Gedik

[Former Member · Accepted solution]

Hello Shaun,

I have seen only very few distributed SAP systems. Back in the old days SAP was advocating this setup because even the big boxes didn't provide really much HW resources. Today I see more and more consolidation, so midrange servers can often handle 4 productive instances (DB+CI) without problems.

Points for distributed SAP instances:

- DB and CI could possibly run on different OS and HW architecture (but why would you want to do that?)

- prevention of resource contention (which is rarely an issue and could be avoided with other technical solutions as well)

Points against distributed SAP instaces:

- higher HW costs / no benefits due to consolidation like shared interface cards etc.

- more OS administration

- more complex SAP configuration/administration/troubleshooting

- higher latency for DB-CI communication

From my personal point of view, consolidation is the most important point. It allows the best utilization of resources with minimal HW costs. Second to that are the reduced administration costs with consolidation. These are serious points which make distributed SAP systems rare.

Regards,

Mark

[stefan_koehler]

Hello Shaun,

especially if you are running on AIX and you want to use LargePages for oracle - you have to split the SAP CI or SAP application servers from the database host ... maybe not the most common case ... but we had to do it.

For more information check sapnote #1387644

Regards

Stefan