Re: Database Server Consolidation

1. Advantages: fewer machines to maintain.
2. Disadvantages:
   1. the fewer machines are much more difficult to maintain. E. g., you cannot upgrade machine A to Solaris 2.7 and leave another application untouched that asks for Solaris 2.6.
   2. artificial and unnecessary dependencies are introduced thus reducing the availability. If the one big box goes down, all projects are stopped. Just remember: if you have two systems with n1 and n2 parts, each part may interact with each other within that system. So you have n1 * n1 + n2 * n2 interactions to consider. If you have one system with (n1 + n2) parts, you have (n1 + n2) * (n1 + n2) = n1 * n1 + n2 * n2 + 2 * n1 * n2 interactions to look at. The difference is 2 * n1 * n2 interactions. So "divide and conquer"!
   3. tuning may be impossible. You may have several small OLTP systems and one big datawarehouse. They differ considerably in their load requirements. Do you tune the box for fast response or high throughput?
   4. problem solving: if something goes wrong it may be very difficult to find the faulty hardware or software piece. Due to b), it may be impossible to fix it.
3. Did it? Yes, our job ancestors did so and we were called to change it back to small manageable systems.

Martin Received on Thu Apr 26 2001 - 03:35:52 CDT