NodeCB: A Comprehensive Study on Real World Concurrency Bugs in Node.js

About NodeCB

Node.js has become one of most popular platforms for building server-side applications. Applications built on Node.js face various non-determinism and may contain intricate concurrency bugs. We present NodeCB, a comprehensive study on real world concurrency bugs in Node.js. Our study is based on 57 real world concurrency bugs, collected from various open-source Node.js applications. We examine their bug patterns, root causes, failure symptoms, manifestation, and fix strategies. Our study reveals many interesting findings and implications, which can promote future concurrency bug detection, testing, and automated fixing.

Our 57 documented concurrency bugs can serve as a basis for future work on finding and fixing them. We have made the collected bugs available online for future studies.

Please use the data only for teaching and research purposes. Should you have any questions, please contact Wensheng Dou ( and Jie Wang (

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Page maintained by Wensheng Dou. Last update: Sept 09, 2017.