[⌛ Resolved?] Unknown infinite loop

[mkalam-alami]

A 100% CPU issue making the server inoperable has been encountered multiple times before and during the 10th Alakajam. I suspect this is related to templating, as the biggest update introduced since the previous jam is the JSX templating system.

• The last occurrence was on september 17th evening ; no issue since the jams has started, which may be a hint. (Oct. 4th update: still never happened)
• I managed to get heapdumps, still need to investigate them more
• I need to set up a reliable way to do thread dumps if possible, which would be more useful

[mkalam-alami]

Happened again on Oct 5th 22:35 UTC, it locked the full server despite the lower CPU priority given to the Node process

[mkalam-alami]

Apache access logs haven't yielded much, here's the last few requested URLs before the 22:35 crash :

[05/Oct/2020:20:43:46 +0000] "GET /post/1380/i-get-the-feeling-well-all-be-seasick-by-the-end-of-the-rating-phase/ HTTP/1.1"
[05/Oct/2020:20:43:47 +0000] "GET /scorespace-alakajam HTTP/1.1"
[05/Oct/2020:20:43:47 +0000] "GET /post/1380/i-get-the-feeling-well-all-be-seasick-by-the-end-of-the-rating-phase HTTP/1.1" 
[05/Oct/2020:20:43:47 +0000] "GET /posts?p=10 HTTP/1.1" 
[05/Oct/2020:20:43:48 +0000] "GET /robots.txt HTTP/1.1"
[05/Oct/2020:21:13:36 +0000] "GET /robots.txt HTTP/1.1"
[05/Oct/2020:21:13:36 +0000] "GET /robots.txt HTTP/1.1"
[05/Oct/2020:22:19:28 +0000] "GET /robots.txt HTTP/1.1" 
[05/Oct/2020:22:19:28 +0000] "GET /robots.txt HTTP/1.1" 

The few Node server logs in that timeframe show nothing special, except a 500 error 40mn before the freeze (now fixed with 380563b).

I have set up per-request server logging just in case it could help, but the crash seems to be more subtle than just something route-specific.

[mkalam-alami]

With my jsx-pistols lib remaining the main suspect, I have optimized its behavior in production mode (instead of a transpiler, it basically becomes a pass-through that only loads the compiled templates using NodeJS' require()). It should reduce its use of resources a lot. I have good hopes it will help.

[mkalam-alami]

Assuming fixed 🤞