Managing Multiprocessor Servers

SAP ASE uses the Virtual Server Architecture™, which enables it to take advantage of the parallel processing feature of symmetric multiprocessing (SMP) systems.

You can run SAP ASE as a single process, as a single, multithreaded process, or as multiple, cooperating processes, depending on the number of CPUs available and the demands placed on the server machine. This chapter describes:

The target machine architecture for the SMP SAP ASE
SAP ASE architecture for SMP environments
SAP ASE task management in the SMP environment
Managing multiple engines

For information on application design for SMP systems, see Performance and Tuning Series: Basics > Using Engines and CPUs.

SAP ASE Kernels
SAP ASE version 15.7 and later includes a threaded kernel and a process kernel.
Target Architecture
The SMP product is intended for machines with a specific set of features, including a symmetric multiprocessing operating system, shared memory over a common bus, 1–1024 processors, cores, or hardware threads, no master processor, and very high throughput.
Kernel Modes
By default, SAP ASE starts in threaded mode, appearing as a single process on your operating system, and using native operating system threads for parallelism. By default, SAP ASE handles I/O with native threads.
Tasks
A task is an executable that is internal to SAP ASE (for example, user connections, daemons such as the housekeeper task, and kernel tasks such as I/O handling).
Configuring an SMP Environment
Configuring the SMP environment is similar to configuring a uniprocessor environment, although SMP machines are typically more powerful and handle many more users. In an SMP environment, you can also control the number of engines.