Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
PWL NY: Simple Testing Can Prevent Most Critica...
Search
Caitie McCaffrey
June 14, 2016
Technology
8
470
PWL NY: Simple Testing Can Prevent Most Critical Failures
Caitie McCaffrey
June 14, 2016
Tweet
Share
More Decks by Caitie McCaffrey
See All by Caitie McCaffrey
Distributed Sagas: A Protocol for Coordinating Microservices
caitiem20
331
22k
The Path Towards Simplifying Consistency in Distributed Systems
caitiem20
1
340
Argus Papers We Love
caitiem20
13
1.2k
The Verification of a Distributed System
caitiem20
22
2.3k
We Hear You Like Papers: Eventual Consistency
caitiem20
14
820
The Verification of a Distributed System
caitiem20
12
780
The Verification of a Distributed System
caitiem20
6
780
A Brief History of Distributed Programming: RPC
caitiem20
31
6.7k
Building Scalable Stateful Services
caitiem20
12
1.6k
Other Decks in Technology
See All in Technology
ビギナーであり続ける/beginning
ikuodanaka
3
760
Beyond Kaniko: Navigating Unprivileged Container Image Creation
f30
0
130
CDKTFについてざっくり理解する!!~CloudFormationからCDKTFへ変換するツールも作ってみた~
masakiokuda
1
140
ビズリーチにおけるリアーキテクティング実践事例 / JJUG CCC 2025 Spring
visional_engineering_and_design
1
120
fukabori.fm 出張版: 売上高617億円と高稼働率を陰で支えた社内ツール開発のあれこれ話 / 20250704 Yoshimasa Iwase & Tomoo Morikawa
shift_evolve
PRO
2
7.7k
OPENLOGI Company Profile for engineer
hr01
1
34k
Claude Code に プロジェクト管理やらせたみた
unson
6
4k
怖くない!はじめてのClaude Code
shinya337
0
400
Connect 100+を支える技術
kanyamaguc
0
200
KubeCon + CloudNativeCon Japan 2025 Recap by CA
ponkio_o
PRO
0
300
Core Audio tapを使ったリアルタイム音声処理のお話
yuta0306
0
190
American airlines ®️ USA Contact Numbers: Complete 2025 Support Guide
airhelpsupport
0
380
Featured
See All Featured
StorybookのUI Testing Handbookを読んだ
zakiyama
30
5.9k
Adopting Sorbet at Scale
ufuk
77
9.5k
Testing 201, or: Great Expectations
jmmastey
43
7.6k
The Pragmatic Product Professional
lauravandoore
35
6.7k
YesSQL, Process and Tooling at Scale
rocio
173
14k
What's in a price? How to price your products and services
michaelherold
246
12k
Intergalactic Javascript Robots from Outer Space
tanoku
271
27k
CoffeeScript is Beautiful & I Never Want to Write Plain JavaScript Again
sstephenson
161
15k
[RailsConf 2023 Opening Keynote] The Magic of Rails
eileencodes
29
9.6k
Automating Front-end Workflow
addyosmani
1370
200k
Raft: Consensus for Rubyists
vanstee
140
7k
Unsuck your backbone
ammeep
671
58k
Transcript
Simple Testing Can Prevent Most Critical Failures: An Analysis of
Production Failures in Distributed Data-Intensive Systems Papers We Love New York - June 2016
Caitie McCaffrey @caitie Distributed Systems Engineer CaitieM.com
None
None
Analyzed Failures in Real World Systems
“A majority (77%) of failures require more than one input
event to manifest, but most of the failures (90%) require no more than 3” Complexity of Failures
“The specific order of events is important in 88% of
the failures that require multiple events Complexity of Failures
“3 Nodes or less can reproduce 98% of Failures” Complexity
of Failures
Unit Tests “A majority of production failures (77%) can be
reproduced by a unit test”
Top Down Fault Injection & State Space Exploration is Expensive
Logging • 76% of the failures print explicit failure- related
error messages • For 84% of the failures, all of the triggering events are logged • Logs are noisy: each failure prints 824 log messages (median)
Catastrophic Failures
Error Handling • 92% of failures were the result of
incorrect handling of non-fatal errors • 58% of faults could have been detected via simple testing • 35% of failures caused by bad practices in error handling code
• Error Handling Code is simply empty or only contains
a Log statement • Error Handler aborts cluster on an overly general exception • Error Handler contains comments like FIXME or TODO Bad Practices
Aspirator Performs static analysis of Java bytecode to detect: •
error handler is empty • error handler over-catches exceptions and aborts • error handler contains phrases like “TODO” or “FIXME”
• 500 New Bugs & Bad Practices • 115 Fasle
Positives • 171 bugs reported • 143 bugs confirmed or fixed Aspirator Results
-developer “I fail to see the reason to handle every
exception” Developer Reactions
“It is often much harder to reason about the correctness
of a system’s abnormal path than its normal execution path ”
Moving Forward • Use a tool like Aspirator that is
capable of identifying trivial bugs • Enforce code reviews of error handling code • High code coverage on error handling code
Questions @caitie