
Driving Organizational Change Through Active-Active Architecture - bdwalter
http://stories.iovation.com/organizational-change-through-active-active-architecture
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justizin
This is a really fascinating problem set for distributed computing. I've been
involved in Active-Active designs that never fully went live, and some Active-
Passive, and I def agree with the criticisms of Active-Passive, and the
assertion that you should fail back and forth regularly to ensure that you
have a procedure that works, and resources that actually match.

It's easy for N+1 to be N+0.8, and at peak load, that may be essentially
worthless.

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eprosenx
Exactly justizin! I find it is actually very difficult to ensure we have not
crossed over that threshold of N+X where X < 1\. You have to test each
application tier after each release to be sure of this, and for app tiers that
have data storage, the results are only relevant when nodes are loaded to
their maximum target data load and in their worst case "availability model
degraded" state. (I am the author of this blog post BTW)

