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Node.js Benchmarking Working Group
https://benchmarking.nodejs.org
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Performance impact of async_hooks #181

Open bmeurer opened 6 years ago

bmeurer commented 6 years ago

I've already started a related discussions on Twitter earlier here, but Twitter doesn't scale for this kind of discussion, so I thought I should move it here, so it's easier to follow the discussion. For background: @jasnell approached me at NodeConfEU in November 2017, asking for help on the performance of async_hooks on the V8 side, especially when it comes to the Promise lifecycle hooks. And I've talked briefly with @thlorenz about it during the conference (although I have to admit that I was using the wrong terminology and thus kinda ruined the conversation, sorry). And we had chatted briefly about this as well with @trevnorris during one of the CTC-V8 calls.

Since Promise based APIs are likely becoming a (big) thing for Node 10 and at the same time there are estimates (i.e. by @ofrobots) that by the end of next year every Node server in enterprise is going to run with async_hooks, we should start a discussion about this early one to stay ahead of the problem before it becomes a real problem for our users.

In the last year @gsathya and @caitp already spent a lot of effort optimizing promises in V8 in general, so we're in a pretty good position wrt. baseline performance!

I'd like to use this forum to come to an agreement on what the concrete use cases are (at least estimate that), which aspects of the performance matter the most (i.e. promises created inside of C++ vs. in JS land), and what are useful benchmarks to drive the performance work in a meaningful way. I think we need both a set of micro-benchmarks to drive certain, in addition to real-world code that makes heavy use of promises, i.e. koa.js or fastify servers maybe? I feel that these benchmarks are most important, otherwise we might easily sink a lot of effort into work that doesn't help real-world use cases in the end. That's why I opened the issue on the benchmarking WG.

Comments and contributions are very welcome!

rochdev commented 5 years ago

I definitely don't expect that it will be an easy task, but it's definitely an issue that is severely impacting APM vendors. I don't know if I'll be able to put a lot of time into it, at least short term, but I'd like to familiarize myself with the issue and how async_hooks currently works in general.

I'll try to join the next Diagnostics meeting. Thanks for the tip!

rochdev commented 5 years ago

I won't be able to make it to this week WG meeting. I'll make sure I stay available for the next one.