There isn't concurrent access in the test when it runs, and a new hdf5 file is created for each test function, so I think this is something intrinsic to the way h5py is doing locking in 3.12.

I'm trying to test a build of h5py 3.9.0 using the --no-network option defined in h5py/tests/conftest.py But the option is not being recognised when launching tests inside python using h5py.run_tests( ...

We summarize our survey and Python performance evaluation of major scientific data formats that are under consideration for access to heliophysics data in cloud computing environments, which provide ...