Question Re: SAP HANA Multitarget System Replication Setup in Technology Q&A

SAP HANA Multitarget System Replication Setup

ravindrakumartbc — Tue, 22 Mar 2022 15:54:23 GMT

Hi , I am Setting up HANA Multitarget System Replication Setup. 2 Nodes at Primary site running on Redhat cluster and further 2 nodes running at DR site ( both is different Cluster ) .primary system A in data center 1 replicates data changes to secondary system B in the same data center. Primary system A also replicates data changes to secondary system C in data center 2. Secondary system C is a source system for a further secondary system D located in the same data center with system C.

i am following the below procedure provided by SAP notes.

Example: Configure a SAP HANA Multitarget System Replication - SAP Help Portal

Procedure

On primary system A in data center 1:
1. Create backups.
2. Enable system replication.
On the local secondary system B in data center 1:
1. Stop the system.
2. Register it to A.
3. Start the system.
On the remote secondary system C in data center 2:
1. Stop the system.
2. Register it to A.
3. Start the system.
On the remote secondary system D in data center 2:

Stop the system.
Register it to C.
Start the system.

any one implemented this solution, My system D is not able to Register with system C. Seems like System D is unable to find active system at C since it is registered as secondary of system B.

Any guidance will be much appreciated.

Thanks in Advance

Re: SAP HANA Multitarget System Replication Setup

ravindrakumartbc — Tue, 22 Mar 2022 15:59:16 GMT

above is the Design setup i am working on.

Re: SAP HANA Multitarget System Replication Setup

amontella96 — Tue, 22 Mar 2022 18:48:18 GMT

hey terrabitconsulting , good that you explained the scenario but can you also attach the error you get?

what's your release+SPS+revision?

cheers!A

Re: SAP HANA Multitarget System Replication Setup

azharuddin — Tue, 22 Mar 2022 18:52:46 GMT

Hi Ravindra,

Since you are trying to connect your system D to C (which is already secondary to A) you need to perform additional steps.

You need to make changes to system C additionally perform the role of Primary system. On HANA Cockpit, log into SystemDB of C and click System Replication tile. Click Enable This System as Primary and click Configure on subsequent screen.

Final step, Login into SystemDB of D and click Stop Database. Go to System Replication tile on system D and Click Register as Secondary. Fill in the subsequent information and click Configure.

I hope this will works.

~Azhar

Re: SAP HANA Multitarget System Replication Setup

ashishranjan9408_54 — Tue, 22 Mar 2022 19:43:30 GMT

Yes , I agree with Azhar , We had a similar requirement .

About the Setups , we had Primary , High Availability and DR.

In order to establish the replication we registered this way Primary -> HA (Primary being the Source)

HA -> DR (HA being the source in this one)

Re: SAP HANA Multitarget System Replication Setup

ravindrakumartbc — Tue, 22 Mar 2022 22:41:33 GMT

Thanks Azhar and Ashish , Needs to perform the steps without DBcockpit in Place . Any Further suggestion on commands.

Re: SAP HANA Multitarget System Replication Setup

dennispadia — Thu, 24 Mar 2022 19:48:45 GMT

Hello Ravindra,
You can use below command to configure your setup.

To register SITE3 as secondary of SITE1, follow below instructions:

SITE3> HDB stop

SITE3> hdbnsutil -sr_register --remoteHost=SITE1 --remoteInstance=03 --replicationMode=async --name=S3 --operationMode=logreplay

SITE3> HDB start

SITE3> hdbnsutil -sr_enable --name=S3

To register SITE4 as secondary of SITE3, follow below instructions:

SITE4> HDB stop

SITE4> hdbnsutil -sr_register --remoteHost=SITE3 --remoteInstance=03 --replicationMode=sync --name=S4 --operationMode=logreplay

SITE4> HDB start

Re: SAP HANA Multitarget System Replication Setup

ravindrakumartbc — Fri, 25 Mar 2022 01:35:49 GMT

Hi dennis.padia and all thanks for your response and guidance .

could you please suggest how Failback shoudl working in this design , specially in the DR Drill where Production data is still intact at SYSTEM A & B. during the drill system should do full failbackreplication or is there way to sync only changes back to System A.