coyote VS concurrencyRunner

ex: https://github.com/microsoft/coyote/blob/main/Samples/Accoun...

Microsoft has a library/tool called Coyote* that helps with testing distributed systems; you can write tests/specifications, Coyote will systematically explore nondeterminism in your system and check if your tests still pass. If there's a failure, it'll show the sequence of events that led to the failing test.

I started a project to implement Raft with a KV-store on top, similar to the article, meaning to use Coyote to test it; I didn't get that far before losing interest, though. It's reassuring to read that it took Phil several months to write the code in the post, it's good to know that this is a decidedly nontrivial problem.

* https://github.com/microsoft/coyote

Something like coyote by MS?

If you're looking for similar concurrency testing in the dotnet world, checkout Coyote:

https://microsoft.github.io/coyote/

https://innovation.microsoft.com/en-us/exploring-project-coy...

MS provides a framework for testing for concurrency issues: https://microsoft.github.io/coyote/.

I suggest you try Microsoft Coyote

Visualizations do help a lot when model checkers and concurrency schedule exploration tools like Coyote find bugs. Coyote include the ability to visualize the traces if you express your concurrency using actors (see https://microsoft.github.io/coyote/#concepts/actors/state-ma...)

It also allows you to implement your own "logger" through which you can emit enough information to construct some cool visualizations. I had a lot of fun working on visualizing an implementation of Paxos using Coyote (then P#) (screenshot at https://ibb.co/TTk2hYb)

If curious, you can learn more in the Coyote website https://microsoft.github.io/coyote

Hi HN,

The tweet links to a couple of tutorials showing how to test an extremely simple CRUD service using Coyote to find concurrency bugs. Developers write simple unit tests whose concurrency is explored by Coyote to find bugs. You might be surprised to learn how we can write a number of interesting concurrency tests for even the simplest of CRUD services.

https://microsoft.github.io/coyote/#tutorials/first-concurre...

I made a little project called Concurrency Runner a while ago to attempt to test these kinds of scenarios: https://github.com/weinberg/concurrencyRunner. It does so by running multiple copies of your process in debug mode with breakpoints set to allow specific interleaved execution paths to be explored. This allows you to trigger concurrency scenarios which are difficult to analyze because they otherwise would rely on random timing. That repo has examples which demonstrate "read skew", "write skew" and "read modify write" concurrency scenarios. I was hoping I could make it into something you could run in CI to actively test for these things. Ultimately it was more of a research project than anything else but maybe someone will find it useful or interesting.

Here's a couple...

This project I made a while ago and never took it further: https://github.com/weinberg/concurrencyRunner. Concurreny Runner allows you to debug multiple running processes simultaneously, with breakpoints set to allow specific interleaved execution paths to be explored. This allows you to trigger concurrency scenarios which are typically very difficult to analyze because they rely on random timing. That repo has examples which demonstrate typical database concurrency issues of "read skew", "write skew" and "read modify write". I envisioned it as something you could run in CI to actively test for these things like we do other integration testing.

This other one is in the sad graveyard of promising projects which I never could devote enough time to: https://forums.tigsource.com/index.php?topic=69545.0. It's an adventure game where I recorded hundreds of panoramic images and stitched them all together into a seamless walkable player experience. One day...