Ruby 2.5 support

Question

Ruby 2.5 support

wjordan opened this issue 7 years ago · comments

Tracking Ruby 2.5 support in this issue.

Running require 'gctools/oobgc/unicorn_middleware' in Ruby 2.5.0 generates the following error:

LoadError (/var/lib/gems/2.5.0/gems/gctools-0.2.4/lib/gctools/oobgc.so: undefined symbol: rb_autoload - /var/lib/gems/2.5.0/gems/gctools-0.2.4/lib/gctools/oobgc.so)

This might be fixed in the next published release of 2.5.x by f6631c30.

Aman Karmani · Answer 1 · Tue Feb 13 2018 10:07:56 GMT+0800 (China Standard Time)

I don't recommend using this OOBGC with Ruby 2.5. The GC has changed significantly and the algorithm used in this gem is no longer relevant.

Will Jordan · Answer 2 · Wed Feb 14 2018 03:52:31 GMT+0800 (China Standard Time)

I don't recommend using this OOBGC with Ruby 2.5. The GC has changed significantly and the algorithm used in this gem is no longer relevant.

Are you sure? Do you have more details or references to profiling, benchmarking, or code-analysis that could help me confirm this?

@peteygao in #11 (comment) responded to your original comment that out-of-band GC still provides significantly different performance behavior compared to Ruby 2.2+'s incremental GC alone, making this gem still relevant in certain use-cases.

In my own monitoring of production metrics on a high-traffic Rails app running Ruby 2.2, I've seen out-of-band GC provide lower average request-latencies over the built-in RIncGC, which is why I still use this gem today and would like to maintain it through a Ruby 2.5 upgrade.

Aman Karmani · Answer 3 · Sat May 19 2018 05:19:49 GMT+0800 (China Standard Time)

See for example https://githubengineering.com/removing-oobgc/

Will Jordan · Answer 4 · Sat May 19 2018 13:50:48 GMT+0800 (China Standard Time)

First, the linked post doesn't specify the specific OOBGC algorithm used. The difference between the naive 'OOBGC every X requests' algorithm and the more nuanced 'OOBGC only when finishing a sweep or when close to the allocation limit' algorithm is extremely significant.

Second, a single example where OOBGC turned out to be unhelpful doesn't contradict the claim that OOBGC for Ruby 2.2+ is still relevant in certain use cases. The benefits are workload-dependent.

Third, my own workload has consistently showed opposite results. I already mentioned that my own production metrics showed OOBGC provided lower average response times in Ruby 2.2. Since then, I've upgraded to Ruby 2.5 using the patch in #17. I just ran a direct side-by-side comparison, and continue to see OOBGC providing slightly (~10%) faster response times in production:

(blue = OOBGC disabled)

Agis Anastasopoulos · Answer 5 · Wed Jul 04 2018 22:44:33 GMT+0800 (China Standard Time)

In our case, we noticed that by removing oobgc our response times at the 90th and 95th percentile got slower by ~10ms. I believe OobGC is still relevant.

Fernando Gonçalves · Answer 6 · Fri Jul 03 2020 01:24:36 GMT+0800 (China Standard Time)

Is there any downside of merge this change?

I would like to use it too, but use it directly from ruby gems and from the original repository would be better than point to the @wjordan fork directly.

Aman Karmani · Answer 7 · Fri Jul 03 2020 02:38:46 GMT+0800 (China Standard Time)

I am not using or maintaining this project anymore. If @wjordan is still using it in production and would like to take over, I am happy to add him as a maintainer.