Here are the definitions for several terms used in this chapter:
Process – an execution environment scheduled onto physical CPUs by the operating system.
Engine – a process running an Adaptive Server that communicates with the other Adaptive Server processes via shared memory. An engine can be thought of as one CPU’s worth of processing power. It does not represent a particular CPU. Also referred to as a server engine.
Task – an execution environment within the Adaptive Server that is scheduled onto engines by the Adaptive Server.
Affinity – describes a process in which a certain Adaptive Server task runs only on a certain engine (task affinity), a certain engine handles network I/O for a certain task (network I/O affinity), or a certain engine runs only on a certain CPU (engine affinity).
Network affinity migration – describes the process of moving network I/O from one engine to another. SMP systems that support this migration allow Adaptive Server to distribute the network I/O load among all of its engines.
