Little help with 70-226 study please

The book I'm using does not seem to explain the relationship between NLBing
and Clusters. I know I can have up to 4 nodes in a cluster and I know there
can be up to 32 host on a NLB so it seems obvious to me that NLBing is not
restricted to a cluster. So how would one NLB across mutable clusters? Also
I was wondering if it would be possible in theory to NLB as individual
groups by putting a proxy server in front of each cluster and just NLB
across the proxies and have 128 host under the NLB?

Thanks
~Ben

 

What book are you using? It is explained in the Sybex book.

I think your confusion is because you are trying to relate them. They are
not related. They are 2 different technologies for 2 different types of
problems - albeit that the problems are similar. They are both high
availability technologies.

Clusters are for things like SQL server, Exchange, file server. Clusters
you generally have to scale up

NLBs are for things like HTTP, FTP. NLB you scale out.

So in a web environment, you might have your web pages served by several
http servers in a NLB configuration. On a network behind that you might
have a SQL database in a cluster configuration.

To make it more complex (and more scalable), you could add a component load
balance (CLB) farm in between the http and sql.

 

I'm using the Global Knowledge Syngress Osborne book. Actually I have found
this book to be full of errors. You might ask how I know there errors when
I'm learning from it. Well one page says one thing and then another page
tells it differently. I'm rather disappointed in this book.

Your explanation does help some. Thank you.

I'm going thought the included CD's examples and practice questions right
now. I'll see how I do on the practice questions before deciding if I need
to buy another book.

~Ben