Enque replication SErver

[Former Member]

EXPERT!!

I am Preparing the pre-requistes for the Installlation of Production on HA server. the document what i downloaded from the OSS about the Installation of HA. the quoted that "if required, you install an enqure replication server"

some one please explain me, if we leave this option on HA server, what will be affect on the HA ?

IS CI + Dialogue Instance should install on Local Disk or Shared disk for the HA ?

Regards

Anwer Waseem

SAP BASIS

[Former Member · Accepted solution]

Hi Anwer,

Ín my opinion it is very helpful to have enque replication service. In case enque service fails and is started on the other cluster node then lock entries are rebuild from the replica table created as a result of this service and hence no roll back is done.

Also it is better to have CI and DI on a shared disk from HA perspective.

Please award points if you found the answer useful.

Regards.

Ruchit.

[Former Member · Accepted solution]

Ruchit

I am using the SQL 2005 sp1 on windows server 2003 IA64

Thanks very much for your expert opinion that enque replication service is necessary for the HA. does roll back exist in sql 2005 as in oracle ?

SAP has mentioned in the installation guide that CI & DI should be on local disk, do not enter the shared disk A(SCS) instances. also the diagram is complete self explanatory that CI on Node A and DI should be on Node B.

Can I use the CI & DI instance on the new shared disk instead of local and A(SCS) disk. ?

If do i use the CI & DI instance on local disk then how the failover will switch to Node B where the CI not exist ?

Regards

Anwer Waseem

SAP BASIS

[Former Member]

Hi Anwer,

Sorry I misunderstood the word shared here? I though you were talking of sharing in terms of windows share or NFS mount. I was talking in terms of logical sharing. Yes of course in your context both CI and DI should be on different nodes which means different physical disks. This logical can be extended for DB instance as well. So yes different phsical disks are needed.

Regarding roll backs yes it exists in MS SQL 2005 as well just as oracle. A roll back will occur if a transaction gets terminated without commit been done in order to avoid database inconsisstency. It is has a feature of all database management systems.

I hope this is clearer now.

Regards.

Ruchit.

[Former Member]

Ruchit!

So, I should have to follow the instruction as written in the installation guide, that CI on Node A (local disk c:\ - e:\) and DI on Node B (local disk c:\ - e:\).

What about the Failover switch to Node B where CI does not exist ?

Does failover kill the session while switching to Node (a/b) ?

Does session remain active while switching to Node (a/b) ?

What about the size of database disk , its fine to 600GB with ECC component with double stack ?

Regards

Anwer Waseem

SAP BASIS