The SAP start service runs on every computer where an instance of an SAP system is started. It is implemented as a service on Windows, and as a daemon on UNIX. The process is called sapstartsrv.exe on Windows, and sapstartsrv on UNIX platforms.
The SAP start service provides the following functions for monitoring SAP systems, instances, and processes.
Starting and stopping
Monitoring the runtime state
Reading logs, traces, and configuration files
Technical information, such as network ports, active sessions, thread lists, etc.
These services are provided on SAPControl SOAP Web Service, and used by SAP monitoring tools (SAP Management Console, SAP NetWeaver Administrator, etc.).
The start service connects the following ports:
HTTP port 5<xx>13 (or sapctrl <xx> in /etc/services), where<xx> is the number of the instance
HTTPS port 5<xx>14 (or sapctrls <xx>) in /etc/services), where <xx> is the number of the instance
The start service uses HTTP port 50013 and HTTPS port 50014 for an instance with number 00.
The standard SAP setup is used for secure SSL communication.
If critical functions (“protected methods”, such as restarting an instance) are not called using a trusted connection, they require authentication with operating system user and password. On UNIX platforms trusted connections go through UNIX domain sockets (/tmp/.sapstream<port-no>), and on Windows they go through “Windows named pipe” (\\<host>\pipe\sapcontrol_<xx>)
The start service is registered automatically in LDAP (Lightweight Directory Access Protocol) if ldap/autoregister = 1 is set in the profile.
The start service is registered automatically in SAP SLD (System Landscape Directory). File slddest.cfg is required in directory DIR_GLOBAL for the registration.
The Web service interface is compatible with the following SOAP implementations: SAP ABAP, SAP JEE, Java Axis, Microsoft .NET.
An SAP instance is started differently on Windows and UNIX platforms.
For both operating systems, the start service requires the SAP profile. If this is not found, the service cannot start. You can find the related error message in file sapstartsrv.log.
The instance is started by the sapstartsrv process, and not directly by the start service sapstart. The process is started by the start service, which ideally is started by the sapinit script when the operating system is booted.
The following figure shows how these processes fit together:
You can also still use the startsap and stopsap scripts to start and stop the instance (standard procedure in older releases).
On Windows the instance is started directly by the start service (process sapstartsrv.exe). The start service is started automatically when the operating system is booted.
The start service reads the instance profile and executes all commands in the instance profile that contain an Execute_ statement. It then starts the processes of the SAP instance in the order in which the Start_Program_ statements are listed in the profile.
Systems and Instances
An SAP NetWeaver Application Server comprises specific entities called “system” and “instance”. The two terms are often used incorrectly and this can cause confusion. Below is a definition of the most important entities contained in ABAP, Java, and dual stack systems. Their relationship to each other is also described.
SAP system – installed software system that provides a defined set of functionalities that are part of an SAP solution. These functionalities are implemented in a set of software components. An SAP system is installed and configured as a unit. It consists of a logical database, one or more application server instances (ABAP and/or Java), central services (such as a message server and enqueue server), and optional components (such as TREX and liveCache). The system is identified by its SAP system ID, which consists of 3 letters or digits (e.g. PRD).
Application server instance – administrative unit that puts together components of an SAP system running on one physical host. Application server instances provide the actual data processing functions of a system and offer the corresponding services. Instances are started, stopped, and monitored as one unit. There can be multiple instances (belonging to the same system or to different systems) on one host. An instance can be uniquely identified by the host name and a two-digit instance number.
There are three different types of systems: The ABAP system, the Java system, and the dual-stack system, which offers both technologies in one system. These system types consist of the corresponding instance types in a homogeneous way, meaning only one type is permitted in the system: ABAP instance, Java instance, or dual-stack instance.
The instance types in turn consist of different processes.
The main instance types are the following:
ABAP server instances are often called “dialog instances”. This term is however incorrect because ABAP server instances and client requests also work as background jobs. They consist of common components such as ICM (Internet Communication Manager), IGS (Internet Graphics Server), and ABAP work processes of different types: dialog (for mostly interactive use), batch (for background processing), update (for update processing, which plays an important role in the ABAP transaction model), and spool (for printing) depending on the purpose of the instance and the work load characteristics.
Java server instances consist of common components such as ICM, IGS, and Java server processes, each running on one Java Virtual Machine (JVM).
Dual-stack instances are a combination of ABAP and Java parts in one instance.
Central services instance (SCS) – each ABAP or Java system has one SCS consisting of a message server for communication between instances and an enqueue server for lock management. Dual-stack systems can have either one shared or two separate SCS instances.
In addition to the instance types described here there are others, such as TREX, Web Dispatcher, and enqueue replication server.
The following monitoring tools use the Web service interface:
SAP Microsoft Management Console: Windows
SAP Management Console
SAP NetWeaver Administrator
sapcontrol: with sapcontrol (process name on Windows sapcontrol.exe) you can call the functions of the Web service interface from the command field. sapcontrol -h shows the syntax and the available options.
You can find information for developers about using SAPControl Web services in SDN at http://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/60e24f7b-1ba1-2b10-c0a0-e514b855624b&overridelayout=true