Customer Reviews

Server Load Balancing

5 star:		(1)
4 star:		(0)
3 star:		(3)
2 star:		(2)
1 star:		(2)

 

 

This deals mainly the web based load balancing. This is the simplest solution since the sessions only last for ms. It has a good hands on approach to router configuration and network design but lacks hardcore application design that this topic deserves.

There is no discussion on complex systems which require sessions to last for days and how to distribute state between multiple servers. There is also no discussion on locking mechanisms, determining load, primary/backup determination, latency across WANs, distributed objects, DB failover, server synchronization, heartbeat implementations, shifting load for scheduled down time, or dynamic router configuration or alternative scheduling mechanism apart from round robin.

I think the title "Web Server Load Balancing" would be a more appropriate title and if that is what your goal is then this is the book for you.

I expected a lot more from this book that while admittedly was the first that covered the topic, but did not really explain things in detail. Half of the book is on configurations that you can download from vendor web sites and the real design issues are never really addressed. The author runs a web site on teh topic and also is a known expert so this made the book more dissappointing.
The first O'Reilly book I have ever regretted buying.

But after digging into the content I was forced to re-evaluate my first impression. I looked to this book to guide me through numerous pieces and choices of server load balancing on a fair but balanced agenda. What I found was far too much information that was simply digested and reformatted from vendor and free areas.

I look to an expert on a topic to give new insight and twists to anything they write. The lack of any personal commitment or recommendation was surprising. Which made the book more into a mid-level technical guide with no path or strategy summary as I would expect. A good beginner type book for the basic information. It was well organized and had decent flow. Chapter 5 seemed to offer the most promise, but never quite concluded with anything concrete.

This publication is good for an quick introductory view of server load balancers. Users of load balancing products from certain manufacturers will benefit from the configuration options discussed in the final section of the book. For a more in-depth discussion, I would recommend Kopparapu's text "Load Balancing Servers, Firewalls, and Caches".

This book gives an organized but purely descriptive overview of server load balancing and should be helpful to anyone who is approaching the subject for the first time but does not require quantitative assessments of the different methods for doing server load balancing. It is written for the network administrator, but anyone, including network managers should find it helpful. Network engineers may find the treatment too qualitative, but it could be supplemented by more rigorous material if needed.

Chapter 1 is a brief overview of the history of load balancing and why it is needed in Internet environments. DNS-based, firewall, and global server load balancing are briefly discussed, along with clustering. This is followed in chapter 2 by a brief review of the OSI model and the different components involved in server load balancing. The author cautions that the use of VRRP (Virtual Router Redundancy Protocol) may cause problems if the load balancers become isolated from each other, but does not give any historical or test examples of this. The same holds true for his caution on the use of fail-over cables.

The discussion becomes a little more detailed in chapter 3, wherein the author discusses the actual functioning of a server load balancer. Direct server return is discussed, with its use of MAC address translation and loopback interfaces. Both server-based and switch-based load balancers are briefly discussed, but the author does not want to commit to which is the better architecture. The inclusion of some benchmarking studies would be helpful here.

Performance metrics, such as connections per second, total concurrent connections, and throughput are discussed in chapter 4. Although the discussion is purely descriptive, the author does give a "metrics matrix" that outlines what metrics are important for different types of traffic.

The author gets down to describing the network infrastructure needed to do server load balancing in chapter 5. The different possibilities for network infrastructure are classified according to the IP configuration (flat-based or NAT-based), the return path (bridge path, route path, or DSR), and physical connectivity (one-armed or two-armed). The advantages of the different types of SLB architectures are discussed briefly, but no real test cases or benchmarking studies are included.

The details of flat-based SLB network architectures are discussed in chapter 6. The simplicity of this architecture is emphasized, along with its ability to pass FTP and stream traffic more readily (no real examples given however).

I did not read the rest of the book which covers administrative matters, and so its review will be omitted.

this is the first O'reilly book that I've been disapointed with! Too many purposeless examples and some configs can be downloaded from vendors web site...am also wondering about the many PETA references for a load balancing book (just off topic)

This was actually a very good book. It really explains the background behind server load balancing very well. However, the book only emphasizes hardware solutions for server load balancing. It doesn't discuss any of the software solutions, such as Windows 2000 or IBM Edge Server.

The only reason why I rated this book relatively low is that much of the theory behind server load balancing can be obtained for free from various web sites.

If you're only looking for information about the concept of server load balancing, then you're better off getting the info from web sites for free. However, if you're also looking for great tips on the various load-balancing hardware solutions, then it's worth purchasing this book.

I found this to be an excellent, clear and concise introduction to web server load balancing and configuration.

Highly recommended.