How is ABAP Central Instance defined?

[Former Member]

Hello,

upto WAS 6.40 the enqueue and message server defined the Central Instance (CI) of an ABAP stack. With the new architecture both services are moved to the ASCS ínstance, but the term CI still exists.

What exactly defines the CI in WAS 7.x ?

Regards BErnd

[Former Member]

OK, thanks.

[Former Member]

Hello,

yes I understand, what you wrote is true. Lets formulate my question a bit different. We have NW2004s, only ABAP stack and ASCS was installed. Then an instance DVEBMGSxx still exists.

- Will the SAP system start when instace DVEBMGSxx is not available?

- When SAP is running and instance DVEBMGSxx is goning down, no HA setup for that instance is implemented, is SAP still able to work?

Regards BErnd

[Former Member]

Hi,

1) when we do the installation we select high availabilty system this will create a cluster which means a paralle system. and High Availability system is used for production servers.

2)As per your requirement suppose when central services are down(DEVMBGSxx) then for that particular system high Availability is available then it will activate the cluster (high available system)and the system will be in running state even if DEVMBGSXX down also.

Regards

Zia

[Former Member]

Hello,

when reading the mentioned document, then ether an ASCS instance OR an CI instance exists. When an ASCS instance was installed then no CI exists anymore.

But I read architecture documents were an ASCS AND CI instance were mentioned. OK, may be the author did not know what he wrote.

Regards BErnd

[Former Member]

Hi ,

With SAP NetWeaver 04 Java, the Message Server and the Enqueue Server are separated from the Central Instance. These two services are grouped within the SAP Central Services Instance (SCS) as services. From NW04s the ABAP Central Services can be also separated from the Central Instance. Each stack, ABAP and Java, has its own Message Service and Enqueue Service. For ABAP systems the Central Services are referred to as ASCS, for Java systems the Central Services are referred to as SCS. The ASCS and the SCS are leveled as SPOF and require a High Availability Setup therefore. If the ASCS is integrated within the ABAP Central Instance (standard in NetWeaver 04) the Central Instance of the ABAP system needs a HA setup also.

Regards

Zia

[JPReyes]

Exactly the same... Simply uses enque replication

Read,

http://help.sap.com/saphelp_nw04s/helpdata/EN/43/e6b0a0d7633886e10000000a1553ed/content.htm

Regards

Juan