Hi team this is a question on how Pants run tests in paralle

Question

Hi team this is a question on how Pants run tests in parallel I have multiple shards of unit tests and I run the command like this ` pants ldebug test test dags shard 1 test dags shard 2 ` What I see from the log is `22 36 33 91 DEBUG Running Run Pytest for airflow2 test python data dag tests dag tests test dags shard 6 py tests under semaphore with concurrency id 8 and concurrency 1` `22 36 33 91 DEBUG Starting Run Pytest for airflow2 test python data dag tests dag tests test dags shard 6 py tests` `22 36 33 91 DEBUG Starting setup sandbox` The message `concurrency 1` makes me think there is actually no concurrency Am I correct Thanks

witty-crayon-22786 · Answer

by default pants will run multiple test files in parallel but it will not run multiple test methods in parallel

witty-crayon-22786 · Answer

what you are seeing there is Pants spawning 1 pytest process and assigning it 1 core

witty-crayon-22786 · Answer

if you want to run methods in parallel you can use <https www pantsbuild org docs reference pytest xdist enabled> but note that it requires that your test methods be concurrency safe

powerful-florist-1807 · Answer

Thanks Stu

busy-vase-39202 · Answer

That d make a cool Pants tip of the Day How s this gt Tip of the Day gt Pants runs multiple test files in parallel by default Want to run multiple test methods in parallel Sure no problem <https www pantsbuild org docs reference pytest xdist enabled> just remember to first make your test methods concurrency safe

powerful-florist-1807 · Answer

Yea it is really cool