High Availiability

[Former Member]

Hi

We are planning for HA in our project. Our SAP setup is as below..

I have gone thru the Installtion manual and collective note on HA

-- it is a 3 system landscape with HA for production server.

-- AIX - 5.3, ORACLE 10G, SAP SR3, dual stack (ABAP + JAVA)

We are going for 2 sytems for production. We want simple HA solution.

I have planned as below.. Pls. correct me if I am wrong..

1. On one node ( Node -A) - I will choose HA Installation from "sapisnt" , it will install ASCS ( standalone enque and message server), I will configure Enque Replication Server (ERS)

2. Dialog instance on other node (Node - B) -

3. IBM HA will sit on Node - A

4. OS guys will help in maping the failover clusters..

Is my understading is correct ?..

Nick

[Former Member]

Hi Nick,

As per my knowledge for HA you can plan as follows:

Assuming at least two nodes for HA.

on first node install

ASCS and SCS

then Install DB on second node

then Install CI on first node

If you want you can install dialog instance in additional application server other than this two nodes

As per your requiremnts you can install as much as Dialog instance.

Regards,

Nitin Salunkhe.

[Former Member]

Hi Nitin,

If I install CI again on 1st node. How the failover hapens. Pls. explain. We have only 2 servers for this. At present we can't afford more servers for additional dialog installation.

Thanks

Nick

[Former Member]

hi Nick,

I have installed HA for AIX 5.3 with oracle 10g but it was ECC 6.0 SR2.

That time we installed CI and DB on differnt node.

When suppose CI's node get shutdown then all mounted file systems from there get mounted on DB server that is second node vice versa.

In more technical details

you have two ips for each node service ip and boot ip.

first server will be booted on boot ip when you start smitty clstart then cluster gets started.

and cluster scripts files mounted related CI files on CI node and DB file on DB node (you have to run smitty clstart on DB also) and then both nodes will be running on service IP which is used by your SAP Application. Simillarly both Ips have corrosponding hostnames.

When one nodes get fails another nodes get assigned down node's service IP and get mounted all required file systems and starts services again.

Eg.

First Node

boot ip : 10.10.10.1

serviceip : 192.168.1.2

hostname : sapci00

Second Node

boot ip : 10.10.10.2

service ip : 192.168.1.3

hostname : sapdb00

suppose CI nodes gets down

then all CI related files get mounted automatically on DB server

and DB server has following IPs you can check with command ifconfig -a

10.10.10.2

192.168.1.3

192.162.1.2

and hostname spaci00 and sapdb00 both will get ping

Hope this will solve your confusion.

I suggest you go by Installation guide for SR3

what I am saying is as per SR2 I dont konw about SR3 guide.

Regards,

Nitin Salunkhe

[Former Member]

Hi Nitin,

Thanks for the valuable inputs. I will confrim you once I complete my installaion.

Thanks!

Nick

[Former Member]

Hi Nitin,

How about Enque replication. I think it is very much necessary ?. what do you think?

Thanks

Nick

[Former Member]

Hi Nick

Ya Eneque replications server I have not installaed.

but from SR3 its important to protect your data updates while switching over happens.

So I suggest you do Eneque replication and test it very well

Regards,

Nitin Salunkhe

[Former Member]

Hi Nitin,

I have completed HA installtion on 1st Node.

Now, I started DI installtion on the second node. I am struck up with this. Afte giving profile path /sapmnt/P01/profile ( it is NFS mounted) _. It is asking for password for the P01adm I supplied P01adm password. ( P01adm is node 1 user)

In ABAP Schema I have maintained standard SAPSR3.

In the mid of the installtion, it says can't create P01adm. it is already exist. It is not allowing me to create an user "P02adm" ( for the second node).

Pls. give me your valuable suggestion.

Thanks

Nick