SAP instances

[simon_164]

Is it possible to create two sap instances and make these instances run each on a node in a cluster?
the two instances should read from the same directory -- which does mean that they should be able to read/write on the same mount point which is /usr/sap/PRD/sys and also the /usr/sap/trans ??

[Geoff Wild · Accepted solution]

Yes it is possible - I used to have this config (Prod on one node and QA on the other) - in the event of a failure in PROD, then QA would shutdown first.

You wouldn't have them R/W the /usr/sap/PRD/sys dir - they each would need their own - but yes, /usr/sap/trans would be an NFS Automount running on the Prod instance, with say the QA instance mounting it.

Rgds...Geoff

[simon_164]

Please can you explain more !! so that I will set it up correctly.

[simon_164]

why would the other one stop?
I am having two instances: CI and AP1.

what i understand is:

- one package will have mounting point:
/usr/sap/PRD/DVGMSxx
- one package will have mounting point:
/usr/sap/PRD/D00
- one package will have mounting point:
/usr/sap/trans
/usr/sap/PRD/SYS
this one is NFS mounted on both systems.

I should also create a dependence from the first and second package to the third package.

[Geoff Wild]

Why would you want to stop the AP1?

Your server may not be able to handle the load of running 2 SAP instances on it. Also - if they have the same "instance number" then you can't run them on the same server.

Typical SAP landscape has Production CI on one server, A QA CI on another, and a DEV CI on a third. All 3 NFS mount /usr/sap/trans (that is correct - even the PROD CI server NFS mounts it).

Is Oracle running on them as well? or just SAP?

Traditionally, /usr/sap/trans is in it's own package.

We used to have separate CI and Oracle packages - but found it was better to have them in the same.

/usr/sap/PRD/DVGMSxx and /usr/sap/PRD/D00 should be in the same package - Production.

/usr/sap/PRD/SYS is usually not in package - just part of /usr as just contains symbolic links...

Rgds...Geoff

[simon_164]

I have only 2 nodes cluster. the database package is on one of them, the CI package is on the other.
I do not have any QA package, I have a CI package and a AP1 package.

both packages should use the directory /usr/sap/trans and the directory /usr/sap/PRD/SYS. this is why i am concerned.
I should mount the NFS from the package which means i need the NFS toolkit ?

Can I add you on my msn because I am beating my head on this? It is totally fine if you dont want.

[simon_164]

how can i access the /usr/sap/PRD/DVGMSxx and /usr/sap/PRD/D00 from different nodes if they are to be on one package only.

[Geoff Wild]

Well, one way would be to build logic in the AP1 package that it won't start if the PRD package is down - and if the PRD package stops - then so must the AP1 one - this creates a lot of work (monitoring scripts, etc) - in cases like this - apply the KISS directive.

I would create a single package for both and have them run on the same node (as the DB is on the other one).

This will save you a lot of grief.

Yes, you want the NFS toolkit and the SAP Extension one.

Rgds...Geoff

[Mel Burslan]

Simon,

the prescription for your problems is HP product # B7885BA, HP SGeSAP integration kit. It has a hefty price tag (in the order of US$ 50K but discounts may apply) and it comes with an HP consultant in general to properly implement and certify the cluster for ongoing HP support. It is nothing magic but in a situation, you spend thousands of dollars on hardware and SG and HP software, I think price of this kit can easily be justified.

[simon_164]

can you scale me on a 1-10 scale, how difficult is to build a sap cluster with oracle database and double instances on a hp-ux cluster without the NFS toolkit and the hp-ux extension for sap. I guess a product for 30000 $ is totally important so that it has this price don't you guess?

[Michael Steele_2]

Refer to chapter six 'configuring packages' in attached.

http://docs.hp.com/en/B3936-90065/B3936-90065.pdf

[Michael Steele_2]

http://docs.hp.com/en/B3936-90065/B3936-90065.pdf

Refer to chap. 6, config. packages in service guard

[Mel Burslan]

in the scale of 1 to 10 of hardship, 10 being hardest, I am not going to tell you that it is at the level 15, but it is a close 8 or 9. Having said that, if you do not purchase this US$30K-50K integration kit, HP will only give you basic MCSG support and that is it. After that you are on your own since SAP does not care if you are running the product on SG environment or on a single server.

So that large amount of money is basically buying you supoort from HP. If you wish, I am sure you or someone with sg experience can figure out how to do it from the sg manuals in a matter of days.

[Geoff Wild]

It would be very difficult to tackle this without the toolkits. I'm a CSE in ServiceGuard and wouldn't want to take that on without letting management know that it will take quite some time to do (so the cost is either in labour or in software).

Rgds...Geoff

[simon_164]

You mean someone can figure out how to do it if he has the kit or without it. I have SG experience but I do not have sap experience. how to stop start instances... I guess always building the cntl script is the responsibility of the application.
I know all the SG manual ("probably"), however doing stuff related to the cntl script is what i miss, i mean mounting Volume Groups, Logical Volumes, IP's. is ok. but mounting NFS is strange for me, monitoring sap and oracle instances is also strange .
I am confused that you said that i can build the cluster in a matter of days -- did u meant with the extension? what about monitoring scripts?

[Geoff Wild]

IMHO with the toolkits it would be a matter of days.

Without them - weeks...but not impossible...

I can't give you the scripts we have - as they are built from the toolkits - and that would be a violation of our contract.

For NFS, the NFS control script has 382 lines of code and the monitor script has 430. The package script has 1357 - but it is the standard package script you get without the toolkit (cmmakepkg).

SAP there's even more - as there are function files as well.

Rgds...Geoff