[regression] NodeOS don't boot with Node.js v0.11.15

[piranna]

Continue discussion from nodejs/node-v0.x-archive#9097.

Since version v0.11.15 of Node.js that changed the version of v8, NodeOS can't boot entering an infinite loop instead of showing a REPL and consuming 100% of CPU. Recent tests showed that this still happen with Node.js v4.1.1

[ChALkeR]

Could you share a small reproducable testcase that shows that this is a bug in Node.js/v8?

[piranna]

You can be able to download NodeOS and generate yourself with npm install, by generating only the barebones is enought. You can check it with npm start and it will start NodeOS directly to a Node.js REPL.

Later, change the version to something bigger than v0.11.14, delete the deps and obj folders to force regeneration with the new version, and exec again npm install: the new one will enter an infinite loop consuming the 100% of the CPU and not showing the REPL.

[ChALkeR]

@piranna I am afraid that NodeOS doesn't fit into «small».
Could you make a self-contained testcase?

[piranna]

nodeos-barebones is the most minimal use case... Besides that, I only can think about upload somewhere a compiled version with v0.11.14 and another with v0.11.15 (or v4.1.1 if you want, but this is still in experimental status and still not merged in master due to the requeriment of GCC 4.8) so you can be able to check both.

[jbergstroem]

I'm not sure if this is a nodejs problem. What API in nodejs do you interface with? v8 is a very moving target which is why you should use NaN whenever possible.

Edit: I recall prior discussions about incompatibilities between musl and node (v8). Guessing that might be related. Even if you get it to compile I wouldn't assume it'll work as intended. It needs a lot of low level work [probably on both v8 and musl sides] and I'm not sure who would be interested in doing that at the moment.

[piranna]

Nodeos-barebones is only vanilla Node.js running directly on top of a Linux
kernel as PID 1, the only special thing is the usage of musl as C lib.
Besides that, code is untouched and are standard compilations.
El 06/10/2015 12:36, "Johan Bergström" notifications@github.com escribió:

I'm not sure if this is a nodejs problem. What API in nodejs do you
interface with? v8 is a very moving target which is why you should use NaN
whenever possible.

—
Reply to this email directly or view it on GitHub
#3204 (comment).

[jbergstroem]

@piranna I'm with @ChALkeR here; your case is specific enough to fall outside the scope of what is relevant to this project versus nodeos. If you can create a minimalistic test case which is debuggable it might be more relevant, but seeing how you're using musl I think thats too much to chew at the moment. Can you reproduce the same issue with glibc?

[ChALkeR]

@piranna nodeos-barebones compiles and builds a Linux kernel. It doesn't fit into my definition of «minimal».
Please, research that issue in your code and create a testcase.

[piranna]

We already checked, read the issue pointed on the first comment: the problem came on Node.js v0.11.15 with the change of version of v8, and a lot of people got problems and regressions then, just check old issues tracker. Seems the problem is due to a spin lock on v8:

nodejs/node-v0.x-archive#9113
nodejs/node-v0.x-archive#25137
nodejs/node-v0.x-archive#25295

[jbergstroem]

@piranna v8 will continue to be updated, and we make sure we ship a nodejs binary that works on our supported platforms. Your peculiar setup I would argue is out of that scope. Can you try building against glibc and report back?

[jbergstroem]

@piranna all linked issues has fixed closed to them. The last one seems to be related to using node.js --prof stuff. Do you use that in nodeos?

[piranna]

No, I can't, we are using musl on NodeOS because glibc is too much complicated to compile from scratch. Node.js supports musl and there's a lot of people using it already, and NodeOS uses a vanilla Linux kernel. You could get a similar environment just by copying the files from your Linux system by hand and put them together, since there are no modified code. Honestly, I don't know why you say it's a peculiar setup...

[piranna]

The last one seems to be related to using node.js --prof stuff

No, I'm not using it, I'm using regular Node.js without flags, but the problem seems to be related, since the results are similar.

[jbergstroem]

@piranna there's no official support of nodejs-baked binaries on top of musl as of yet. We're exploring this as part of making smaller docker images, but its still a work in progress. As per above, compile time doesn't mean runtime.

I don't have much to add from here. If anyone else wants to chip in and learn the innings of nodeos that would probably be a next step since we won't get a reduced case.

[piranna]

The Node.js binary used on NodeOS with musl works correctly on Ubuntu when pointing to the musl libraries, and as I told you, NodeOS uses a vanilla Linux kernel and Node.js v0.11.14 works but newer not. The only different thing between NodeOS and an Ubuntu environment that could explain this issue is the usage of /dev/console as stdio. Besides that, it's a plain regular Linux system.

And regarding NodeOS internals, honestly there's not too much to learn here...