Bug #21205
Updated by Peter Amstutz 6 months ago
User reported "duplicate key value violates unique constraint index_collections_on_owner_and_name".
This error occurred from arvados-cwl-runner creating a collection called "Intermediate collection".
This case does supply the ensure_unique_name flag.
However, it seems that between running 100s of workflows, and this particular step doing a 24-way scatter, that it attempting to create ~10 collections per second (see screenshot), and that, while < 1% chance, it is evidently possible for two or more collections to be created at the same time and for save_with_unique_name! to fail enough times in a row that one of those collection create operations fails with a uniqueness error.
I propose two tweaks to make this function more robust:
# increase max_retries from 2 to 10
# make the "sleep" statement pick a random sleep time between 2 and 10 milliseconds instead of always sleeping for exactly 2 milliseconds