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#pex
Title
# pex
h

hundreds-father-404

10/20/2020, 8:04 PM
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?
h

happy-kitchen-89482

10/20/2020, 9:50 PM
Probably performance by default, with documentation on how to downtune if necessary.
h

hundreds-father-404

10/20/2020, 9:51 PM
Okay. I think I’m comfortable with
cpu_count() / 2
- not super likely to OOM fwict