SAP Technical Architecture guide
SAP Architecture & Provisioning
Understand PAS, AAS, ASCS, ERS, SAP Web Dispatcher, SAP HANA, and the control points in an SAP provisioning workflow.
Component responsibilities
The Primary Application Server (PAS) hosts the initial ABAP application-server instance. An Additional Application Server (AAS) adds application capacity and can improve distribution/availability. ASCS provides central services such as message and enqueue services. ERS replicates enqueue data so lock information can be recovered during a central-services failover. SAP Web Dispatcher is an HTTP(S) reverse proxy/load balancer in front of SAP application endpoints.
Architecture flow
UUsers / browsers → WDSAP Web Dispatcher WD → PASPrimary Application Server WD → AASAdditional Application Server PAS → ASCSASCS: message + enqueue AAS → ASCS ASCS → ERSEnqueue Replication Server PAS → DBSAP HANA AAS → DB
Provisioning control points
Pre-install: confirm product/version, maintenance plan, media, checksums, OS/database support, hosts, ports, SIDs, instance numbers, storage, users and rollback plan. During SWPM: define approved parameters, review them, execute the selected service, and monitor logs. Post-install: verify instance/service state, logon, database connectivity, central services, licensing, clients, transports, security and backups.
For an AAS, know the target host, SAPSID and instance design. For ERS, identify the ASCS instance being replicated and the approved ERS host/instance. For Web Dispatcher, treat master credentials, certificates, back-end routing and network exposure as security design: not sample values to copy.
Active recall
Test yourself
1. Which component preserves enqueue information for central-services failover?
Reveal answer
ERS replicates the enqueue state from ASCS.
2. Why is Review Parameters a separate SWPM phase?
Reveal answer
It is the final control point to catch incorrect, destructive or environment-specific values before execution.
3. Does adding an AAS create another database?
Reveal answer
No. It adds application-server capacity and normally connects to the same SAP system/database.
Practice this module
This guide maps to 3 questions in the SAP Technical Architecture Top 40 bank.
Open practice