HA for ECC 6.0 cluster setup

[former_member597396]

HI Experts,

                We are planning for our ECC system on HA, below are the environment details

SAP / DB / OS          :     ECC 6.0 / Oracle 11.2.0.3 / AIX 7.1

Node A : DB + ERS(10)

Node B : ASCS(01) + CI(00) + ERS

Node C : DI(02)

Node D : DI(03)

Here in Node A : DB & in Node B : ASCS(01) are in cluster (AIX - HACMP).

1) Kindly let me know is their any need of any DI/CI with same instance number (i.e. 00) in DB node.

2) Also request you to comment on any care if need to be taken.

[Sriram2009 · Accepted solution]

Hi Saravanan

Kindly follow the steps

1. Central services instance for ABAP installation.

2 Central services instance for JAVA installation.

3 First MSCS node installation

4 Database Instance  Installation using backup restore method

5 Additional MSCS node installation

6 Enqueue replication server installation for ABAP in Node I (10)

7 Enqueue replication server installation for JAVA in Node I  (12)

8 Enqueue replication server installation for ABAP in Node II (10)

9 Enqueue replication server installation for JAVA in Node II (12)

10Central Instance Installation in Node I

11 Secound node installation as per the installation guide 

12 Post processing steps after system copy

Kindly go thru the Installation Guide link - http://service.sap.com/instguides and SCN link

http://scn.sap.com/docs/DOC-8761

Thanks

Ram

[former_member252185]

How is ERS installed in Unix VCS cluster setup?

Is ERS installed on first host with Virtual name or host name?

coz' ASCS will include enque. So, ERS job is to replicate the lock table on both cluster hosts. So. Per windows, you have to install ERS on a local mount in /usr/sap/<SID>/ERS<instance #> on both hosts.

However, sap latest unix install guide says to use virtual host name for ERS when installing in first node of the cluster. and move the cluster resources and install ERS on secon node. but, for second node they did not mention if I have to use virtual host name or hostname.

any thoughts, knowledge and Best practice would help me. thanks in advance

[Former Member]

Dear Saravanan,

The above solution for active-active solution is perfect. Also underlying Cluster HA architecture should support this active-active functionality. For this information contact your  HA Hardware partner.

If you think to go with Active -Passive solution. Here is the solution.

Node A : ASCS (09) + DB (Should be installed in cluster group)+CI (00) (Should be installed locally)

Node B : DIALOG (00) (Should be installed locally) -->(During failover DIALOG acts Like a CI and ASCS & DB Cluster groups will be moved to NODE B).

Node C : DI(01) -->Application 1  will be installed on ( Node C ) for Load Balancing

Node D : DI(02) -->Application 2 will be installed on ( Node D ) for Load Balancing

Note : I think in Active Passive Installation.ERS Installation is not mandatory for ABAP Stack Installations. ERS Installation is recommended for JAVA Installations since frequency updates on DB  is more.

I would like some one to threw some light on ERS installation with NW731 EHP1.

The below lines drifted from http://scn.sap.com/docs/DOC-25454#section38.

The Enqueue Server contains the central locking table for the SAP cluster. Besides database locks it also consists of infrastructure locks of system wide

objects. It is therefore necessary to secure the locking table in case of a Standalone Enqueue Server failure. The SAP Enqueue Replication Server provides a

replication mechanism for the Enqueue Server by holding a copy of the locking table within its shared memory segment. After a failure of the Enqueue Server

the locking table can be restored this way. Since SAP NW04 SP15/ NW04s SR1 an automated installation of the Enqueue replication server is available for

Windows environments.

some information on ERS -UNIX/ Linux installations are handled by SAP hardware partners.
Note: you can only protect Stand-Alone Enqueue Servers with an Enqueue Replication Server. The standard Enqueue Server in an ABAP CI (Enqueue work process) cannot be protected by an Enqueue Replication Server.

Thanks,

Shankar Reddy Dalli.

[former_member188883]

Hi Saravanan,

Your configuration looks ok.

Just you need not have ASCS and ERS on the same host as ASCS will perform the same work like ERS in that node. In Node B you can have only ASCS + CI.

Once the installation is done, perform cluster failover testing to confirm your configuration is correct or not.

Hope this helps.

Regards,

Deepak Kori

[former_member597396]

Really appreciate your expertise, am In process of starting migration today. Expecting to complete in next 3-4 days. Will surely let you know with the test resulta of switch-over.

Currently going forward with the below set up.

Node A : DB + ERS(10) + DI(00)

Node B : ASCS(01) + CI(00) + ERS(10)

Node C : DI(02)

Node D : DI(03)

Here in Node A : DB & in Node B : ASCS(01) are in Active-Active cluster (AIX - HACMP).

ANY COMMENTS ARE MOST WELCOME

Will update you on the same shortly.

Warm regards,

Saravanan.