how to upgrade the system to High-Avaibility

[Former Member]

Hi all

I have a problem with requirement of my customer following

In current, for economic reasons of my customer, so they have just two server (A and C) and they want me to install SAP system on Server A and C (Customer required A must be application and C database)

But in the future (maybe approximately 6 months after), they will purchase more two server , so call Server B and D, they want to upgrade their system up to High- Avaibility system (HA)

Server A, B will run SAP application server (per server install a Dialog Instance)

Serrver C, D run database server (per server install a Central Instance and Database Instance) for HA

C <cluster> D

I need the advice of everyone for this situation

My Question : at the present, I will to install on server A and server C how more convenient for later

If people have documents and would send to me

Forward to detailed instruction

Thanks all

[Former Member]

thanks for your advices

@ Raghu :

You can install as a distributed system where you install ASCS,SCS,CI on server A and DB instance on Server B

At the present, my customer only have two server and so called A and C (not A and B) for easy identification in this thread

Question 1: For your opinion, at the present with two server, i will install a Distribute System model on A and C (server A : installed ASCS, SCS, CI and server C: installed DB) ?.

Question 2: Besides Distribute System model , a way of two server installations to make easier to upgrade HA later ?

Then later when you have two more servers, you can build the cluster between A & B i.e CI and DI cluster

When i have two more servers (B and D), Follow me, I think of two situations:

Queston 3 for Situation 1: (in Distribute system model)The first, i will export entire database on server C. Then, I will rebuild A and C, combined with B and D and i install a default system of HA template on server A, B, C and D. And the finally, i will import database again ? Pls, Forward for comment ...

Question 4 for Situation 2 : (in Distribute system model) Your opinion, i will build the cluster between A and B, i.e CI cluster (but, in this case, server A is already a CI, so need not rebulid server A) ? In this case, how cluster A and B, pls show me. Pls, Forward for comment ....

Also you can build a DB Active Passive cluster on Server C & D. (Unless it is RAC)

Question 5 for Situation 2: (in Distribute system model) in this case, server C is already a DB, so need not rebuild server C, how cluster Active-Passive between C and D. Pls, show me .... Why not Active-Active (RAC) ? RAC has done in this case is not?

Thanks for your comment details.....

[Former Member]

Hi,

The above comments are more confusing to me

The best approch i can think of here is, Install a HA system with two nodes. Install ASCS,SCS,CI on one node and install the DB Instance on the other node.

When you two new servers, attach one node to CI instance installing Dailog Instance for load balancing ( Note:You need web dispatcher or hardware load balancer).

The second new server attach it to the DB Instance, as a passive DB node. Then build the cluster softwares seperately for CI DI and DB Instance.

I am not quite sure of RAC, because you are installing a Oracle without RAC now.

You need not export the database to other server. You can use the same database server as Active Node.

I still recommend not to do it if its a production server because, you might need lot of downtime later when configuring the clusters.

Cheers....,

Raghu

[Former Member]

Hi all

@Raghu:

Do you need a cluster for DB instance also later when you have four servers ?

Yes, I will setup a cluster after i have four servers later

If you want CI and DI on two nodes and DB Instance on a seperate cluster, then you have break the existing CIDB cluster and do a CI DI Active-Active cluster and Active-Passive cluster for Database

For economic capicity of my customer are not allowed, so only two server (A and C), so that each instance can not be installed on each server

Therefore, at the present, on the two server is available (A and C), i will install how to facilitate later

Example:

In the two models installed of SAP (Distribute system and High-avaibility), i will choose model for the installation on current two server ?

In Distribute system, i will install DI on server A and CI-DB on the server C is not ? Or i have to install CI on server A and DB on the server C more convenient to upgrade HA later

If you have documentation for details on setting up tow server (A and C), pls send to me

thanks all

Edited by: myfriend280985 on Nov 4, 2009 5:08 AM

[Former Member]

Hello,

HA systems require the use of virtual hostnames. The most important thing to do is to install the systems using the sapinst parameter SAPINST_USE_HOSTNAME. This will properly setup and configure your systems for HA, whether or not you are using HA now. Future conversion of systems to virtual hostnames can be difficult and time consuming. Once installed with virtual hostnames, switching your configuration to HA later as you described will not be much of an issue.

Best Regards,

Matt

[Former Member]

Hi,

You can install as a distributed system where you install ASCS,SCS,CI on server A and DB instance on Server B.

Then later when you have two more servers, you can build the cluster between A & B i.e CI and DI cluster.

Also you can build a DB Active Passive cluster on Server C & D. (Unless it is RAC)

This is workable solution. But still i recommend not to do it if you are trying to implement this directly on the Production Server.

If you can implement this on test servers and then if all the steps are established, then you can do the same with Production server.

Cheers....,

Raghu.

[Former Member]

This may help you []

[Former Member]

Hi,

Do you need a cluster for DB instance also later when you have four servers ?

If not, you can utlise the other two servers for load balancing keeping CIDB on a cluster.

If you want CI and DI on two nodes and DB Instance on a seperate cluster, then you have break the existing CIDB cluster and do a CI DI Active-Active cluster and Active-Passive cluster for Database.

You can do it. Only thing is you will have a virutal hostname or IP for your Database Instance which you need to set in DEFAULT profile. Also you have install a dialog instance.

These all can be done at SAP level. Your Cluster partner should support this. Please check with Cluster Vendor whether they can rebuild the clusters.

Hope this helps.

Cheeers....,

Raghu

[Former Member]

Please, somebody help me ....

thanks all

[Former Member]

hi all

@Raghu: DB: Oracle 10g, OS: RedHat Enterprise 64bit, cluster sofware: CRS

My company's customers are tough economically, but they still want a system of HA and that they think will do it (because of their IT that do it) and they want my company what to do if on.

this made me difficult because I never do as their requirements

Expect all our consultants help with a solution by my customer

thanks all

[Former Member]

Hi,

Can you please let us know which OS,DB and the cluster software you are using you are using.

The scenario is very complex and i am really not sure whether this can be done due to below resons.

1. The Cluster software binds the IP addresses which is difficult to change once the system is ready.

2. You have to clone the database instance to another system which is risky.

3. You have build the database cluster and rebuild the application cluster with an additional app server which will very complex.

If the server is a test system, then you can give a try. But if its going to be Production System, i dont recommend to do this. You can explain this your customer.

Cheers........,

Raghu

[Former Member]

hi all

@ Javed Sapstar : you don't understand my comments. Clearly, problem here is my customer still want to install HA system but now they have problems financially and they just want me to install on two server (A and C) ablove and later they will purchase two more server (so call B and D) to upgrade to HA system.

the reason so I want to seek comments on all installed on server A,C. How to make it easier to upgrade later and downtime at least, so the change is at least

@ Anil Bhandary : ABAP + JAVA

Would people advice to help how to install how best. At present, install something on server A and C to make it easier to upgrade the system later

thanks all

[former_member227283]

Hi,

will i be abap only or abap + java installtion ???

thanks

Anil

[Former Member]

I guess the best way for you will be migration. For this, you will need to export/import the data. Anything else would be too manual and therefore too risky because you are introducing HA and you should install HA as clean as possible else there is risk of breaking down.

As for document, you can refer to standard SAP documentation for OS migration.

Warm regards,

Javed

[sunny_pahuja2]

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