Tester's Digest

A weekly source of software testing news


ISSUE #3 - Feb 20th, 2017

I try to focus on one main topic in each weekly issue of Tester’s Digest, with news sprinkled in.

Topic: Testing Distributed Systems

In today’s world, you’d have to be in a rather niche space to not be testing distributed systems, so most aspects apply whether you’re testing a system built on microservices, a web app that relies on AWS for its backend, an online game, or a large-scale NoSQL database. Global village, you know.

This remains required reading for newcomers to distributed systems (testers and coders alike):


Great list of testing resources:


The challenges of scaling a system, as experienced by Uber, with “what I wish I knew” style lessons, and a prominent mention of load and failure testing:


How Facebook does load testing in production (live! but safely)


How do you uncover bugs in distributed storage systems during testing, rather than in production? These Microsoft folks exercised a test harness against systems written in the .NET framework, and found 8 bugs in MS Azure products that were hard to find with traditional testing techniques.


The two posts above come from The Morning Paper, a blog I hugely respect.

On the probability of data loss in large clusters, with the math (subtly incorrect, so be sure to read the comments about replication time being a factor in mean time to data loss):



A recent post on migrating data at scale, safely (Stripe’s account, pretty standard dual-writing approach). Does not cover the testing angle… left as an exercise to the reader?



One approach to spreading good testing practices while, uh, not spreading germs. I swear this is not an April Fool’s post:


As proof that the above was not a joke, here is the most recent installment of Testing on the Toilet, direct from Google’s restrooms to yours:


There were maybe a dozen posts total over the years, search for “testing on the toilet” to see them all.

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