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
Model Mondays S2E04: AI Developer Experiences
nitya
0
120
AIの全社活用を推進するための安全なレールを敷いた話
shoheimitani
2
510
LangSmith×Webhook連携で実現するプロンプトドリブンCI/CD
sergicalsix
1
230
LLM時代の検索
shibuiwilliam
1
150
AI時代の開発生産性を加速させるアーキテクチャ設計
plaidtech
PRO
3
160
関数型プログラミングで 「脳がバグる」を乗り越える
manabeai
1
190
KubeCon + CloudNativeCon Japan 2025 Recap Opening & Choose Your Own Adventureシリーズまとめ
mmmatsuda
0
280
PO初心者が考えた ”POらしさ”
nb_rady
0
210
AWS認定を取る中で感じたこと
siromi
1
190
Tokyo_reInforce_2025_recap_iam_access_analyzer
hiashisan
0
190
NewSQLや分散データベースを支えるRaftの仕組み - 仕組みを理解して知る得意不得意
hacomono
PRO
2
160
「クラウドコスト絶対削減」を支える技術—FinOpsを超えた徹底的なクラウドコスト削減の実践論
delta_tech
4
170
Featured
See All Featured
A designer walks into a library…
pauljervisheath
207
24k
Agile that works and the tools we love
rasmusluckow
329
21k
Performance Is Good for Brains [We Love Speed 2024]
tammyeverts
10
950
The Cult of Friendly URLs
andyhume
79
6.5k
I Don’t Have Time: Getting Over the Fear to Launch Your Podcast
jcasabona
32
2.4k
It's Worth the Effort
3n
185
28k
Optimising Largest Contentful Paint
csswizardry
37
3.3k
Become a Pro
speakerdeck
PRO
29
5.4k
How GitHub (no longer) Works
holman
314
140k
Gamification - CAS2011
davidbonilla
81
5.4k
The Success of Rails: Ensuring Growth for the Next 100 Years
eileencodes
45
7.5k
Building Adaptive Systems
keathley
43
2.7k
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