BKVXCLST.RVW 930910 Digital Press PO Box 3027 One Burlington Woods Drive Burlington, MA 01803-9593 800-DIGITAL (800-344-4825) VAXcluster Principles, Davis, EY-M740E-DP-CRE, 1993 If "principles" were all this book dealt with, it would only be fifteen pages long. What we have here, rather, is a very detailed description of the component parts of a VAX cluster - other than the VAXen themselves. Communications channels and devices, storage hardware, and the various system files and utilities are examined. Included in this overview are some of the underlying principles of those components. Although it is somewhat unfair to ask a technical work to conform to the same literary standard as other works, the style here could definitely use improvement. We are given the same (word for word) definition of a VAX cluster twice in the first eight pages, and the same (Digital specific) definition of a network twice within twelve pages. I know we are talking about fault tolerance here, but some of the redundant material could easily be removed. At the same time, the formatting of the text and the use of bullets and indenting is often confusing, especially when multiple levels of bullets and indents get mixed on a single page. Since the VAX cluster is implemented only on proprietary machinery and a proprietary operating system, it is not surprising that much of the material is hardware and operating system specific. Scattered throughout the work, however, are gems of generic interest, such as the well-defined structure of an Ethernet packet, right down to the diagrammed description of Manchester phase encoding of data. Chapter one is an introduction to the topic. Unfortunately, it is possibly the most confusing part of the book. Chapter two, discussing the outline of Systems Communication Architecture (SCA) is somewhat better, but still a bit ragged. (For example, having almost completed the description of SCA, we are given a simplistic analogy of SCA likened to a telephone system. This might better have been an introduction.) Davis is obviously more at home with the guts of the system, and the book improves a great deal as chapters three through eight delve into interconnects, storage architecture and options, locking, the Connection Manager, and miscellaneous topics. The work is replete with specific examples and notes regarding particular devices. It is not simply a reproduction of the documentation and marketing notes, though. The material is well-organized, and gives details about the underlying structures before moving on to details of operation. This may be frustrating for some who merely want a "cookbook", but for the curious it can be an interesting and potentially valuable excursion. For those considering the installation or configuration of a cluster the book will give valuable background and guidance. Those already managing VAX clusters may not find an immediate need for it, but will probably deepen their understanding of the system. Those running MVS, of course, won't have the slightest idea what I'm talking about. copyright Robert M. Slade, 1993 BKVXCLST.RVW 930910 ====================== DECUS Canada Communications, Desktop, Education and Security group newsletters Editor and/or reviewer ROBERTS@decus.ca, RSlade@sfu.ca, Rob Slade at 1:153/733 Author "Robert Slade's Guide to Computer Viruses" (Oct. '94) Springer-Verlag