Warnings and Limitations

Experimental Software

h5s3 is currently not robust software. Assume it does not work correctly. This package is in a pre-release phase so that people may begin testing and providing feedback.

Concurrent Access

h5s3 does not turn hdf5 into a database. Amazon S3 is only eventually consistent and does not provide atomic access to objects nor locking mechanisms.

For safe, deterministic access, you may either have:

  • Exactly one read-write user at a time.
  • Unlimited read-only users.

While a user is writing to a file, changes will not be sent to other clients. Other clients will still see stale data for a potentially unlimited amount of time. If two clients are writing to a file at the same time, their writes will not be sent to each other, so stale data may overwrite new data when flushing the client’s in-memory pages to S3. For these reasons, we recommend sticking to one of the two usage patterns described above.