Instance number strategy

[Former Member]

I am interested in developing an instance numbering strategy and would appreciate feedback from anyone who has developed a tested numbering scheme.

I work at a large installation with dozens of SAP instances including CI, app servers and Web Dispatchers. Since most of the these systems are on separate servers or virtual containers, there has been no conflict with ports if the system numbers are the same. Going forward, we are facing installation of additional DEV and QAS landscapes and I want to choose instance numbers wisely since they aren't easy to change.

Also, Adaptive Computing provides the ability to move instances to different hosts easily but only if the the instance numbers are unique to prevent port conflicts.

Are there any other technical considerations beside duplicate ports when choosing system numbers?

I would appreciate any feedback about your number rules or polices.

Keith

[Former Member]

I do not know how much of this will help you, but this is the strategy that we follow

We have 150+ sap systems running on different servers without any virtualization, In come cases we have as many as 15 instances (dailog, CI etc) on same server, so the port numbers have to be different for all the systems to work

This is what we follow

1) Each SAP system will have a different number uniqiue.g 01, 02 , 03 etc ( All instances of the system like dialog, CI should use the same number) . In cases where SCS comes into picture two numbers get assgined to the system

2) Production systems have a different number range (as they are on a seperate set of servers)

3) One physical server will not host more than more instance of the same system

4) CI and dialog instances are always on seperate sets of servers

5) Before installing a new system the system number has to be assigned from a common system number repository.

6) When the system gets deleted the system number is cleared for re-assginment in the system nuber repository

[hemanth2]

HI Keith,

Apart from the numerous changes that will need to be made to the profile files (and others in the system itself), I cannot think of anything apart from the transport (/usr/sap/trans) directory.

You will need to check file /usr/sap/trans/bin/TPPARAM and change all occurences of old instance number to new one, e.g the definition of startsap-file.

Also 97-99 cannot be used for instance numbers.

I dont think there are any more changes needed other than the ones inside the server..

Kind regards,

hemanth

[Former Member]

Hermanth,

Thanks for your reply, however, I think you misunderstood my question. I am not interested in changing existing system numbers.

I AM interested in developing a numbering system before installing several new systems. When installing SAP, sapinst defaults to system number 00 and SCS number 01. Application servers and Web Dispatchers also have systems numbers which default to 00. Most of our existing systems use those numbers and we have not have a problem since most are on separate hosts with different IP addresses.

The only problem I see with NOT having unique numbers is potential port conflicts if you try to run two applications (CI, DI, WD) with the same system number on the same host. Are ports the only place where systems number are important?

I'm looking for suggestions from anyone who may have come up with a numbering system. I've thought about:

- Assigning separate ranges for DEV/QAS and PRD since we will never run DEV/QAS systems with PRD systems.

- Separate ranges based on CI, DI or WD

I would appreciate any suggestions.

KS