SAP NetWeaver 7.x on UNIX with Db2 on IBM Cloud® VPC

Core platform features

SAP NetWeaver uses ABAP or Java core platforms to support the SAP applications. SAP NetWeaver:

• Has application lifecycle management capabilities.
• Provides the basic structure for the on-premises versions of SAP Business Suite and other applications, as an application server.
• Is the foundation for the on-premises SAP S/4HANA next-generation business suite, with SAP HANA serving as the sole underlying database.

SAP provides a list of the SAP versions to learn more about the versions available in IBM Cloud. Each support package stack has a leading software component version. The support package level of each component version is a key part of the stack and a unique identifier for the support package stack.

Installation types

The three installation types for SAP NetWeaver Application Server are:

• ABAP System– You can run ABAP programs and some SAP Java apps
• Java System– You can run only Java Platform, Enterprise Edition apps. No ABAP programs can be run on a Java system
• Dual Stack – You can run both ABAP and Java Platform, Enterprise Edition in separate instances

Standard system

In a standard system, all main instances run on a single virtual server instance within a private subnet. For more information, see About virtual server instances for VPC. The virtual server instance has these components:

Architecture of SAP NetWeaver AS for ABAP

SAP tools create a PAS Instance and an ASCS Instance. This method is the standard for Java Stack (System) and is now standard for ABAP Stack.

1. The Primary Application Server (PAS) - An instance is an administrative unit that contains various components of an SAP system. The components of an instance are parameterized in a shared instance profile. Each instance is identified by a system ID and an instance number and includes:

   • SAP Web Dispatcher & Work Process (DIA,BTC,UPD,SPOOL) - The SAP Web Dispatcher lies between the internet and your SAP system. The SAP Web Dispatcher is the entry point for HTTP and HTTPs requests into your system, which consists of one or more SAP NetWeaver application servers. As a “software web switch”, the SAP Web dispatcher can reject or accept connections. When it accepts a connection, it balances the load to ensure an even distribution across the servers. The SAP Web Dispatcher contributes to security and also balances the load in your SAP system.

     You can use the SAP Web Dispatcher in ABAP and Java systems, in pure Java systems, and in pure ABAP systems.

   • SAP Gateway Service - The SAP Gateway carries out RFC services within the SAP world, which are based on TCP/IP. These services enable SAP Systems and external programs to communicate with one another. RFC services can be used either in the ABAP program or for the external programs that use the interfaces. RFC can be used between processes of an instance or a system, or between systems.

   • ICM (Internet Communication Manager) Service - Application server component that receives and dispatches Web requests (HTTP(S), SMTP, …). ICM evaluates the URL and forwards requests to AS ABAP or AS Java.

   • IGS (Internet Graphic Server)

2. The ABAP Central Services Instances (ASCS) – This instance contains the message server, the enqueue server, and a separate start. The ASCS instance cannot process any dialog requests. It is used to manage locks, exchange messages, and balance workload in the SAP system. The ASCS instance includes:

   • Message Server - The SAP message server runs as a separate process, mostly on the same host as the central instance. If an SCS instance (SAP Central Services) or ASCS instance (ABAP SCS) is configured in the system, the message server is part of this instance.
   • Stand-alone Enqueue Server - Part of the central instance (ABAP or Java)that manages the SAP locks. In combination with the enqueue replication server, this single point-of-failure can be made into a high availability solution.
   • ABAP Central services instance (ASCS instance) - Contains the ABAP message server and the stand-alone Enqueue Server
   • The enqueue replication server instance is only mandatory in a high-availability system.

Optionally, you can install the ASCS instance with an integrated:

• SAP Web Dispatcher. For more information, see ASCS Instance with Embedded SAP Web Dispatcher.
• Gateway. For more information, see ASCS Instance with Embedded Gateway.

Architecture of SAP NetWeaver AS for Java

1. Java central instance (J< nn > instance) – A Java instance is a unit in the AS Java cluster that is identified by its instance number. The elements that form an instance that is run on one physical machine. Also, it is possible to run several instances on one physical machine, but it is recommended that you split the different instances among different physical machines. A AS Java Cluster Architecture consists of:

   • Internet Communication Manager (ICM) - The ICM is an element of the Java instance that handles requests coming from clients and dispatches them to the available server processes. Data is transferred from the ICM to the server processes and vice versa by using the Fast Channel Architecture (FCA), which allows fast and reliable communication between them
   • One or several server processes - The server processes of AS Java run the Java application. They are responsible for processing incoming requests that are assigned to them by the ICM. Each server process is multi-threaded, and can therefore process many requests simultaneously.

2. System Central Services instance (SCS instance) - Central services form the basis of communication and synchronization for the AS Java cluster. They are responsible for lock administration, message exchange, and load balancing within the cluster. Central services that are run on one physical machine and constitute a separate instance. This SAP Central Services Instance (SCS) comprises:

   • Message Server - The message server keeps a list of all server processes in the AS Java cluster and provides information about their availability to Internet Communication Manager (ICM). It also represents the infrastructure for data exchange between the participating server processes.
   • Enqueue Server - The enqueue server manages logical locks. The enqueue server runs on the Central Services instance of the Java cluster. It manages the lock table in the main memory and receives requests for setting or releasing locks. It maps the logical locks to the database.

Db2 for standard system

• Database instance (DB) - Db2 in this case. For more information, see AnyDB - IBM Db2 and Infrastructure certified for SAP.

• Primary application server instance (PAS instance) - The global directories of the ASCS instance can be used as the global file system. That means that the host with the ASCS instance is the SAP global host. However, you can also separately install the global directories on any host of your SAP system landscape. You can also use the SAP transport host or the host with the global file system (SAP global host) as your primary application server instance host. Optionally, you can install one or more extra application server instances.

• Additional Application Server (AAS) - You can install one or more extra application server instances for an existing SAP system. Additional application server instances are optional and can be installed on separate hosts.

  An extra application server instance can run on:

  • The host of any instance of the existing SAP system
  • On a dedicated host

Distributed system

In a distributed system, there are multiple virtual server instances and every instance can run on a separate host:

The components in a distributed system are the same as the components in a standard system, but there are restrictions as to which instances can go on which hosts.