Event Distribution Service

NetPlane Core Services

 

 

2.5.3.2.1Message Queue Director

The Message Queue Director (MQD) runs as process on a system manager node. Its main tasks are:

z Maintaining location and state data of all queues and queue groups in a system z Resolving all queue and queue group names and location information

z Supporting group change tracking on behalf of registering clients

There is an active and a stand-by MQD running respectively on the two system manager nodes. MQD uses the NCS Message based Checkpoint Service to keep the two synchronized and available for failover situations.

2.5.3.2.2Message Queue Node Director

The Message Queue Node Director (MQND) runs as process both on payload and on system manager nodes. Its main tasks are:

z Managing queue send/receive operations initiated by Message Queue Agents (MQA) z Creating, maintain and destroy queues

z Notifying MQAs when messages are delivered, received or when tracked group traits change

z Destroying a queue if its creator process dies or a retention timer expires z Preserving messages until fetched or queue is destroyed

2.5.3.2.3Message Queue Agent

This is a linkable library that makes all MQSv APIs available to applications.

2.5.4Event Distribution Service

The Event Distribution Service (EDSv) is compliant with the Event Service APIs defined by the SAF.

This service controls the multiplexing of event messages in a publish/subscribe environment. It exposes a rich set of APIs which allow applications to control event distribution criteria. The implementation details of the event distribution mechanism remain transparent to the application. In the NCS environment, the EDSv uses the underlying Message Distribution Service (MDS) to implement the communication channels.

The EDSv functionality is closely linked with other NCS services, such as System Definition, Availability Service and Checkpoint Service.

2.5.4.1Architecture

The EDSv consists of the following two parts:

zEvent Distribution Server (EDS)

zEvent Distribution Agent (EDA)

NetPlane Core Services Overview User’s Guide (6806800C08B)

31

Page 30 Page 32
Page 31
Image 31
Motorola 6806800C08B Event Distribution Service, Message Queue Director, Message Queue Node Director, Message Queue Agent
Page 30 Page 32

6806800C08B specifications

The Motorola 68000 microprocessor, particularly the revision marked as 68000C08B, stands out as a seminal component in the evolution of computing technology. Introduced in 1979, the 68000 architecture laid the groundwork for many advanced systems, influencing a multitude of platforms, from personal computers to game consoles.

The Motorola 68000C08B features a 16-bit data bus and a 24-bit address bus, allowing for a memory addressing capability of up to 16 MB. This architecture was pioneering for its time, enabling more extensive and complex software applications than its predecessors. The C08 revision particularly emphasized optimizing power consumption while maintaining performance, making it ideal for embedded systems and portable devices.

One of the 68000's key characteristics is its unique register set, which allows for a versatile range of operations. It consists of 8 general-purpose data registers and 8 address registers. The architecture supports both integer and floating-point operations, thanks to an integrated instruction set that facilitates complex mathematical computations, crucial for applications in graphics and gaming.

In terms of performance, the 68000 processor operates at clock speeds ranging from 8 MHz to 16 MHz, depending on the specific variant. The instruction set architecture (ISA) is known for its orthogonality, meaning that most instructions can be used interchangeably across different registers. This design simplicity allows for efficient coding and faster execution times, a significant advantage for developers.

Another remarkable feature of the 68000C08B is its capability for multitasking and improved context switching. Its advanced memory management, combined with support for virtual memory in later implementations, catered to the needs of operating systems and real-time applications, making it suitable for both consumer electronics and industrial machinery.

The Motorola 68000 family also supports a variety of peripherals, enhancing its flexibility as a microcontroller. This compatibility allowed manufacturers to create diverse product lines, from keypads and mice to modems and hard drives.

In summary, the Motorola 68000C08B microprocessor not only advanced the landscape of computer technology in the late 20th century but also helped set the stage for future innovations through its architecture, performance capabilities, and versatility in numerous applications. Its legacy continues to influence modern computing paradigms, ensuring the 68000 remains an essential chapter in the history of microprocessors.
Top Page Image Contents