Unprecedented levels of uncertainty threaten the architecture of many global firms. Six principles of biological systems can help companies address the unknown and the unknowable.

"In this guest blog, Karen Deignan of Net-Works interviews Christina Ulardic of Swiss Re and Marjorie Brans, formerly of Oxfam America, to find out how they worked together to create the R4 Rural Resilience Initiative to tackle climate risk in Africa"

"The R4 Rural Resilience Initiative is a comprehensive risk-management initiative that helps smallholder farmers in Africa cope with the impacts of climate change. ...
R4 currently reaches over 40,000 farmers (about 200,000 people) in Ethiopia, Senegal, Malawi and Zambia through a combination of four risk-management strategies: improved resource-management through asset creation (risk reduction), insurance (risk transfer), livelihoods diversification and microcredit (prudent risk taking) and savings (risk reserves)."

"Swiss Re provided the insurance component, but there were other components designed to ensure farmers could grow their crops successfully, get access to micro-credit to buy more seeds, and build up some savings."

Bitrot

robustness principle is a design guideline for software:

Be conservative in what you do, be liberal in what you accept from others (often reworded as "Be conservative in what you send, be liberal in what you accept").
The principle is also known as Postel's law, after Jon Postel, who wrote in an early specification of TCP:[1]

TCP implementations should follow a general principle of robustness: be conservative in what you do, be liberal in what you accept from others.

Fail a deployment when instances are not coming up healthy
Over the years, a few times we fell into a bad state when a deployment succeeded, and instances came up, but they weren’t healthy and were not in fact able to handle traffic appropriately. The “successful” deployment gave us a false sense of security which quickly vanished when a critical service wasn’t actually healthy, and requests were quickly stacking up and failing, sometimes causing a retry storm and all kinds of havoc. From these experiences, we learned how important it is to fail a deployment when instances come up, but aren’t healthy.

Spinnaker has a flexible means for associating instance health. When an instance is unhealthy, Spinnaker will note it accordingly; what’s more, unhealthy instances won’t receive traffic. In the event of all instances in an ASG being unhealthy, Spinnaker will fail a deployment. To make it easier for operators, Spinnaker also clearly marks instance state as coming up, starting, waiting for discovery, unhealthy, and healthy with different colors, as can be seen below.

Ubiquitous compute power has created frequent impedance mismatches between client capabilities and server capacity in distributed systems. Careful client behaviour design protects the server from unintended load and enables safe recovery after outages. These techniques improve resiliency both in microservice environments (where they protect microservices from each other) and in more traditional client-server environments (where a large number of clients such as mobile phone apps might be stacked against a comparatively small number of servers.)

Lovely graphic

Cities from five continents have been selected to contribute to the development of a global framework for water resilience. The City Water Resilience Framework, developed by Arup with support from The Rockefeller Foundation, will help cities better prepare for and respond to shocks and stresses to their water systems.

Amman, Cape Town, Mexico City, Greater Miami and the Beaches, and Hull were selected because they represent the range of water challenges facing cities around the world. With the exception of Hull, each city is a member of 100 Resilient Cities–pioneered by The Rockefeller Foundation.