Vocabulary · Volume 1 and Volume 2

Failure group

Resources assumed to become unavailable together in a specified scenario. Independence between groups is an assumption requiring evidence, not a property conferred by naming them differently. Degraded capacity is what remains after a group is lost: in the book's service, 48 workers at 250 requests per second each, or 12,000 requests per second.

The definition appears in the Volume 1 glossary and Volume 2 glossary. This page collects where the book uses the term and where the blog takes it up.

Discussed in the book

Chapters where “Failure group” is discussed at length, ranked by how directly each section treats it.

Volume I, Chapter 2: Capacity Is a Decision
Sections: Specify the work before naming the size
Volume I, Chapter 4: The Simplest Practice
Sections: How to read this chapter · Find a choice that can be ready
Volume II, Chapter 23: What Scale Brings
Sections: The portfolio at ten times the bill

Failure group

Discussed in the book

See also