AristaDBA’s Oracle Blog….

Oracle’s Real Application Cluster(RAC) is database’s industry’s most innovative, popular and (obviously) complex technologies. Using RAC and with a careful planning and proper design of the application, a shop can achieve immense scalability and performance without going for a very high end hardware. This is the reason, now a days, almost every shop that runs Oracle database, is having at least one implementation of RAC for sure and the numbers are keep on growing worldwide ensuring and establishing the fact that RAC is indeed one of the best technical milestones achieved by Oracle corp and with the upcoming releases of it for the version 11g, it has become even better!

You can read more about RAC from the below links,

http://www.oracle.com/us/products/database/options/real-application-clusters/index.html

http://en.wikipedia.org/wiki/Oracle_RAC

Being innovative technology means that RAC must be a complex piece of technology as well. Well, that should hardly come as any surprise since in RAC, there are many moving pieces and even within RAC, there is a lot that keeps on going all the time which makes it a tough thing to grasp. Though Oracle documentation does a very good job in explaining its in-how but still, its always welcome to have more information. That’s why, a book over such a complex technology is always a welcome thing. Being very advanced technology, there are just a handful of books available for it and the number is even lesser for the latest version 11.2. All these facts make the book, Oracle 11gR1/R2 Real Application Clusters Essentials from my friend Syed Jaffar Hussain and Ben Prusinski, published by Packt Publications a must-buy book!

There are always two approaches to write about a technical topic, write the internal but mostly, non-usable stuff in a real world and another, write what is going to be usable in the real life, production systems. The RAC Essential books does a very good job in making a dba very well aware about the RAC technology and holds her hand to go through with different aspects of it in a step-by-step process. The language chosen is simple, the layout within the chapters for the content is clean and doesn’t confuse one when he is reading the chapter.

The chapters start with the introduction of the high availability architecture making the reader understand that why such technology like RAC is needed. There can be several types of failures which may bring the business down and using RAC some of those failures can be taken away and one can still let the business run. With that introduction, the chapter goes into the introduction of several jewels under the umbrella of the MAA(Maximum Availability Architecture) which includes RAC, Data Guard, Streams and so on.This chapter should make the reader aware and confident about the technology and also would make him understand the necessity of it as well.

The chapter 2 starts with the RAC architecture thus diving deeper into the technical aspects of the RAC technology. This chapter also discusses the necessary hardware requirements such as network and storage, something which can be a very crucial factor in the RAC installation and configuration. With a very detailed presentation of it, the chapter goes more deeper with the explanation of some crucial processes of RAC with the discussion about ASM , the new features of 11.2 RAC and so on. With that knowledge in hand, the next chapter , chapter 3 should come easy for the reader since its about the installation and configuration of RAC. Since there are differences in the configuration of 11.1 and 11.2 RAC, the authors have tried to explain both the configurations so that the difference becomes evident to the reader.

The chapter 4 is devoted to the Automatic Storage Management(ASM). Those who are not keeping track with the latest new features of ASM, or even those who don’t know about ASM before, both should get a good deal of info about its architecture, configuration and most importantly the new things introduced in it by Oracle from 11.2. A detailed description of ASMCMD is also given which in itself has become a very elaborated utility from 11.2(there are about 60+ commands in it now compared to around 14 in the previous versions) .

The next chapters, 5, 6 , 7 and 8 covers up the most important that is needed by a production DBA to manage and administer a clustered environment. There is a lot that RAC offers and some things in RAC land are completely different compared from the single instance world. These chapters are covering the information about the debugging, handling the backups within the clustered environment and also about performance tuning, things which are not different compared to single instance but when done on RAC, come up with couples of new surprises which are covered up in these chapters. If you are not familiar with RAC before, I would suggest to read these chapters couple of times so that you can sync up the concepts and understand fully what’s there.

My favorite chapters from the entire book(just for the record, I liked the entire book) are the chapters 9 and 10 which cover up the part of upgrade and also some of the real world problems which both the authors are very well aware being old veterans in the database world. There are different ways that one can use to upgrade clustered environments and its not really a piece of cake many times. Since there can be many different bells and whistles that one would find in his own environment, may be not all the instructions given in the chapters may be applicable in the exact form but still, having an idea given here is going to be very useful for DBA to understand the entire life cycle of doing it. In the same way, its not possible that one would be lucky enough to see all the errors in his own environment, the chapter’s information about some of the real world issues related to RAC would come very handy when someone would see such things in his own world.

The 2nd last chapter is devoted to describe that how one can use the RAC in the E-biz environment. Strictly speaking about me here, since I am not having any knowledge about E-Biz, I just had a glance at it. But knowing that E-biz is a very complex piece of technology, the given information to manage it over RAC, I think it should come very useful to those DBA’s who manage it in their shops.

The book concludes with the discussion of some other components of MAA like data guard, streams and explains their usage with RAC. A detailed description of these components is provided in this chapter. Besides this, there is a very handy description of some the most useful goodies for the dba’s to be used in the clustered environment are given in a separate section. I guess that would be among the most used sections of the book.

Both Syed and Ben has done a very good job in choosing the topics , making their layout in terms of content and finally, writing them out. As I said already, RAC is something which needs that one must refer to a good book to understand it and since there is a lot of change in the 11.2 RAC, this book has come just in time for all who are willing to have a book which would prove as a very valuable addition in making the old concepts refreshed and describing the new concepts in a clear and simple manner! My sincere thanks and best wishes to Syed and Ben for their efforts to bring this book to us, the oracle community. And last but certainly not the least, my sincere thanks to Packt Publication as well for getting all the hard work done to make this book come to us. Well done guys!