Hey, I’m thinking we should change the default for

[python-setup].resolver_jobs

, which translates to Pex’s

--jobs

. It controls Pex’s concurrency level. We set the default low to 2 because—before we added the single resolve optimization—it was common to build multiple PEXes at the same time. This resulted in exhaustion / an OOM issue for Toolchain, which was tricky to figure out. Now that we generally only do a single resolve at any given time, I think we can bump it higher. Pex’s default is

cpu_count()

. I’m thinking we do

cpu_count() / 2

. But, when you run

./pants package ::

, that may do multiple Pex resolves at the same time. And if you don’t have a constraints file, then this is a bad change. So I’m not sure: optimize for absolute safety vs. better performance?

Probably performance by default, with documentation on how to downtune if necessary.

Okay. I think I’m comfortable with

cpu_count() / 2

- not super likely to OOM fwict