Enable yjit

[just1602]

Before we merge #3038, we should add one of the following environment variable to production : RUBY_YJIT_ENABLE=1 or RUBYOPT="--yjit", so ruby is gonna run with yjit enabled, which is supposed to make our application faster and reduce some resources' consumption over time.

[veganstraightedge]

✅ I have set RUBY_YJIT_ENABLE=1 in both staging and production

Thanks @just1602!

[veganstraightedge]

I've reverted this change because we're now seeing too much memory usage in production.

I'll leave this issue open to re-investigate in the future.

[just1602]

What are our options here? Can we increase our manage the quantity of memory every dyno have?

This is possible, I think the JIT compiler have a bigger memory footprint.

[veganstraightedge]

I have re-enabled YJIT in staging and production

[veganstraightedge]

What are our options here? Can we increase our manage the quantity of memory every dyno have?

This is possible, I think the JIT compiler have a bigger memory footprint.

The WEB_CONCURRENCY ENV var was set to 4 in production.
For now, I've set down to 3

[bensheldon]

I noticed you're using the jemalloc build pack. Have you set a MALLOC_CONF?

You likely want to set:

MALLOC_CONF="dirty_decay_ms:1000,narenas:2,background_thread:true"

https://gist.github.com/jjb/9ff0d3f622c8bbe904fe7a82e35152fc

[veganstraightedge]

thank you @bensheldon! i just set that in production.