Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), February 2008

Understanding Serviceguard Extension for SAP on Linux
The Replicated Enqueue
Chapter 1 25
A stand-alone version of the Enqueue Server is included with the
binaries of SAP kernel 6.40. The stand-alone version of the Enqueue
Server has the ability to create a copy of its memory content to a
Replicated Enqueue Service that needs to be running on a remote host.
This is a real-time copy mechanism and ensures that the replicated
memory accurately reflects the status of the Enqueue Server at all times.
Figure 1-3 Replicated Enqueue Clustering for ABAP or JAVA Instances
Enqueue Services also come as integral part of each ABAP DVEBMGS
Central Instance. This integrated version of the Enqueue Service is not
able to utilize replication features. The DVEBMGS Instance needs to be
split up in a standard Dialog Instance and a ABAP System Central
Service Instance (ASCS). The ASCS Instance will then use the stand-alone
Enqueue Server and is able to replicate its status. On the alternate node
a Replicated Enqueue needs to be started that receives the replication
information. The Serviceguard Extension for SAP on Linux packaging of
dbciC11
arepC11
arepC12
dbciC12
Serviceguard Extension for SAP on Linux Cluster
shared disks
node1
node2
Application servers not part of cluster
Replicated Enqueue with
two systems