6.4 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Cascading failure | 2/3 | https://en.wikipedia.org/wiki/Cascading_failure | reference | science, encyclopedia | 2026-05-05T14:35:55.208170+00:00 | kb-cron |
=== Example === Network failures typically start when a single network node fails. Initially, the traffic that would normally go through the node is stopped. Systems and users get errors about not being able to reach hosts. Usually, the redundant systems of an ISP respond very quickly, choosing another path through a different backbone. The routing path through this alternative route is longer, with more hops and subsequently going through more systems that normally do not process the amount of traffic suddenly offered. This can cause one or more systems along the alternative route to go down, creating similar problems of their own. Related systems are also affected in this case. As an example, DNS resolution might fail and what would normally cause systems to be interconnected, might break connections that are not even directly involved in the actual systems that went down. This, in turn, may cause seemingly unrelated nodes to develop problems, that can cause another cascade failure all on its own. In December 2012, a partial loss (40%) of Gmail service occurred globally, for 18 minutes. This loss of service was caused by a routine update of load balancing software which contained faulty logic—in this case, the error was caused by logic using an inappropriate 'all' instead of the more appropriate 'some'. The cascading error was fixed by fully updating a single node in the network instead of partially updating all nodes at one time.
== Cascading structural failure == Certain load-bearing structures with discrete structural components can be subject to the "zipper effect", where the failure of a single structural member increases the load on adjacent members. In the case of the Hyatt Regency walkway collapse, a suspended walkway (which was already overstressed due to an error in construction) failed when a single vertical suspension rod failed, overloading the neighboring rods which failed sequentially (i.e. like a zipper). A bridge that can have such a failure is called fracture critical, and numerous bridge collapses have been caused by the failure of a single part. Properly designed structures use an adequate factor of safety and/or alternate load paths to prevent this type of mechanical cascade failure.
=== Fracture cascade ===
Fracture cascade is a phenomenon in the context of geology and describes triggering a chain reaction of subsequent fractures by a single fracture. The initial fracture leads to the propagation of additional fractures, causing a cascading effect throughout the material. Fracture cascades can occur in various materials, including rocks, ice, metals, and ceramics. A common example is the bending of dry spaghetti, which in most cases breaks into more than 2 pieces, as first observed by Richard Feynman. In the context of osteoporosis, a fracture cascade is the increased risk of subsequent bone fractures after an initial one.
== Other examples ==
=== Biology === Biochemical cascades exist in biology, where a small reaction can have system-wide implications. One negative example is ischemic cascade, in which a small ischemic attack releases toxins which kill off far more cells than the initial damage, resulting in more toxins being released. Current research is to find a way to block this cascade in stroke patients to minimize the damage. In the study of extinction, sometimes the extinction of one species will cause many other extinctions to happen. Such a species is known as a keystone species.
=== Electronics === Another example is the Cockcroft–Walton generator, which can also experience cascade failures wherein one failed diode can result in all the diodes failing in a fraction of a second. Yet another example of this effect in a scientific experiment was the implosion in 2001 of several thousand fragile glass photomultiplier tubes used in the Super-Kamiokande experiment, where the shock wave caused by the failure of a single detector appears to have triggered the implosion of the other detectors in a chain reaction.
=== Finance ===
In finance, the risk of cascading failures of financial institutions is referred to as systemic risk: the failure of one financial institution may cause other financial institutions (its counterparties) to fail, cascading throughout the system. Institutions that are believed to pose systemic risk are deemed either "too big to fail" (TBTF) or "too interconnected to fail" (TICTF), depending on why they appear to pose a threat. Note however that systemic risk is not due to individual institutions per se, but due to the interconnections. Frameworks to study and predict the effects of cascading failures have been developed in the research literature. A related (though distinct) type of cascading failure in finance occurs in the stock market, exemplified by the 2010 Flash Crash.
== Interdependent cascading failures == Diverse infrastructures such as water supply, transportation, fuel and power stations are coupled together and depend on each other for functioning, see Fig. 1. Owing to this coupling, interdependent networks are extremely sensitive to random failures, and in particular to targeted attacks, such that a failure of a small fraction of nodes in one network can trigger an iterative cascade of failures in several interdependent networks. Electrical blackouts frequently result from a cascade of failures between interdependent networks, and the problem has been dramatically exemplified by the several large-scale blackouts that have occurred in recent years. Blackouts are a fascinating demonstration of the important role played by the dependencies between networks. For example, the 2003 Italy blackout resulted in a widespread failure of the railway network, health care systems, and financial services and, in addition, severely influenced the telecommunication networks. The partial failure of the communication system in turn further impaired the electrical grid management system, thus producing a positive feedback on the power grid. This example emphasizes how inter-dependence can significantly magnify the damage in an interacting network system.
== Model for overload cascading failures == A model for cascading failures due to overload propagation is the Motter–Lai model.
== See also ==
== References ==