Introduction

Models and Concepts

 

 

1.2Models and Concepts

The Checkpoint service comprises three distributed subparts that maintain the cluster-wide checkpoint database.

zCheckpoint Director

zCheckpoint Node Director

zCheckpoint Agent

Figure 1-1 Checkpoint Service -Subparts

CPD

CPD

Payload Blade 1

Payload Blade 2

active

standby

 

 

CPND

CPND

CPN D

C PND

C PA

C PA

CPA

C PA

A pplication

A pplication

A pplication

A pplication

Node SMH 1

Node SMH 2

 

 

CPD - Checkpoint Director

 

Communication path (MDS)

CPND - Checkpoint Node Director

 

Communication path (MBCSv)

CPA - Checkpoint Agent

 

 

 

SMH - System Manager Host

 

 

1.2.1Checkpoint Director

Checkpoint Director (CPD) runs as a process on a system manager node. CPD maintains the centralized repository of control information for all checkpoints created in the cluster. The CPD also maintains the location information of active replicas for all the checkpoints opened in the cluster. In case of non-collocated checkpoint, the CPD designates a particular node to manage an active replica for that checkpoint and also decides on the number or replicas to be created which depends on the policy (See section 8.1.5.1 Usage of Non-Collocated Checkpoints, for policies). Two instances of CPD are configured, one on each system manager node, in order to achieve high-availability. The two instances are configured to be part of a service group having a 2N redundancy model.

1.2.2Checkpoint Node Director

There is one instance of the Checkpoint Node Director (CPND) on each system manager and payload nodes. It is modeled as a separate process. CPND maintains the detailed information of the Checkpoints referred from that node and the corresponding updates and retrievals that operate on those checkpoints. CPND also handles the requests issued by the CPA instances on behalf of its client applications on the same node. In case of checkpoints that have been created with the collocated attribute and the asynchronous update option, the application will

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Checkpoint Service Programmer’s Reference (6806800C47B)

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Motorola 6806800C47B manual Checkpoint Director, Checkpoint Node Director, Introduction Models and Concepts
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6806800C47B specifications

The Motorola 68000 series microprocessor, which includes the 68000, 68010, 68020, and others, significantly impacted the development of computing technology. Among its variants is the Motorola 68000, often referenced for its advanced features, performance, and capacity for versatility, making it one of the most prominent processors in its time.

The Motorola 68000, with its 16-bit data bus and 32-bit internal architecture, provided a potent combination of speed and efficiency. This processor features a clock speed ranging from 5 to 25 MHz, enabling high-performance computing for a range of applications, from personal computers to embedded systems. It utilizes a sophisticated instruction set that accommodates complex operations, enabling developers to write efficient and powerful software.

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The architecture of the Motorola 68000 is notable for its orthogonal design, which provides a rich set of addressing modes, making it versatile for various programming tasks. Its instruction set includes operations for arithmetic, logic, and data manipulation, coupled with strong support for multitasking and complex data structures, essential for modern operating systems.

In terms of technology, the Motorola 68000 employed a dual-processor architecture that enabled it to work alongside other processors, such as the Motorola 68881 and 68882 floating-point coprocessors, significantly enhancing its computational capabilities especially in graphics, scientific calculations, and complex algorithms.

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The 68000 microprocessor also gained popularity in the world of gaming and graphics, being utilized in iconic devices like the Sega Genesis and the Atari ST series. Its performance and flexibility in diverse applications ensured that the 68000 series left an indelible mark on the evolution of computing technology, influencing generations of system design.

In conclusion, the Motorola 68000, particularly the 68000 series, is a foundation in microprocessor history, celebrated for its capabilities in memory management, software development, and multi-faceted applications that paved the way for modern computing.
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