Sunday, 18 August 2013

Optimism vs. Pessimism

Recently I've read a nice maxim by Bill Clinton "Every person has an optimist and a pessimist side. The trick is to be optimist on bad days and pessimist on good days".

In the technology world, we still live up to the optimism of the 50ies, it's considered anti-innovative, even anti-social, when concerns are brought up - unless you directly describe how you solved them. This begins with interviewers looking for  10x, Ninja and Rockstar programmers, assuming agile processes will work more productive amongst superstars, born with success and hyper-productive. Or people argue resilience is a bunch of fault-tolerant servers and session state in a distributed database that will make sure transactional safety for us (we don't care how), or delegating it to a messaging system that will encapsulate flow from us (we don't care how), or a hardware load balancer that will normalize access (we don't care how). But it's not relying on superpowers that creates successul networked systems. Evolution has told us: it's communication, the best communicating group of the fittest will win.

We're only at the very beginning of understanding complexity and peer-to-peer-networks. The military has a long history in understanding complex networked systems involving humans and therefore error. Looking at the current discussion around drones the problem does not seem to be ultimately solved. For our systems to achieve a kind of "Byzantine fault tolerance" against infrastructure errors, we need a new approach to concurrency and consistency. Once we include business-critical processes in distributed systems, we need to make sure information is valid - in the eye of the beholder. Usually, transaction safety is considered ubiquitous, but we need systems more like MVCC, that gives one user the impression of consistency, yet allowing concurrent modifications in limited scope. True Resilience is about having the user chose between optimistic and pessimistic locking, and providing a relevant consistency context for the user, hyper-consistency if you want. In military, logistics is key. In the same way, having access to trusted, coherent, resources, is key in our distributed systems.

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