We have some heavy tests which consume a lot of memory for t

Question

We have some heavy tests which consume a lot of memory for these tests we want to restrict the parallelism Is there a way to reduce parallelism for some tests While letting other tests run in parallel

wide-midnight-78598 · Answer

This might be a starting point <https www pantsbuild org docs troubleshooting controlling test parallelism>

gentle-gigabyte-52115 · Answer

Indeed I was looking at this ``` process execution local parallelism=1``` I wouldn t want to do because it will reduce performance ` pytest execution slot var` I don t really understand how this could be used to control parallelism

happy-kitchen-89482 · Answer

`execution slot var` is not used to control parallelism it names an env var that will contain a slot number that your tests can use to assign unique databases or other resources

happy-kitchen-89482 · Answer

I don t think there is a way to restrict parallelism for specific tests in a single pants run But one thing you can do is create separate `python tests` targets for those heavy tests and be sure to exclude those tests from the sources of the `python tests` target that owns the other tests in the same dir Then you can <https www pantsbuild org docs advanced target selection tags annotating targets|tag> the heavy test targets Then you can run Pants twice once with ` pants test process execution local parallelism=1 tag=heavy ` and again with ` pants test tag= heavy `

gentle-gigabyte-52115 · Answer

Thanks Benjy I think that would work indeed

ambitious-actor-36781 · Answer

If you use the pytest xdist parallelizer you could use xdists segmentation functionality