The Allspaw-Collins effect

While reading Laura Maguire’s PhD dissertation, Controlling the Costs of Coordination in Large-scale Distributed Software Systems, when I came across a term I hadn’t heard before: the Allspaw-Collins effect:

An example of how practitioners circumvent the extensive costs inherent in the Incident Command model is the Allspaw-Collins effect (named for the engineers who first noticed the pattern). This is commonly seen in the creation of side channels away from the group response effort, which is “necessary to accomplish cognitively demanding work but leaves the other participants disconnected from the progress going on in the side channel (p.81)”

Here’s my understanding:

A group of people responding to an incident have to process a large number of signals that are coming in. One example of such signals is the large number of Slack messages appearing in the incident channel as incident responders and others provide updates and ask questions. Another example would be additional alerts firing.

If there’s a designated incident commander (IC) who is responsible for coordination, the IC can become a bottleneck if they can’t keep up with the work of processing all of these incoming signals.

The effect captures how incident responders will sometimes work around this bottleneck by forming alternate communication channels so they can coordinate directly with each other, without having to mediate through the IC. For example, instead of sending messages in the main incident channel, they might DM each other or communicate in a separate (possibly private) channel.

I can imagine how this sort of side-channel communication would be officially sanctioned (“all incident-related communication should happen in the incident response channel!“), and also how it can be adaptive.

Maguire doesn’t give the first names of the people the effect is named for, but I strongly suspect they are John Allspaw and Morgan Collins.

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