Committing Fedora 6 transactions in parallel

[Basil Marti]

Hi everybody

For one of our customers, docuteam is using Fedora 6.4.1 running under Tomcat on a Windows server. For storage we're using a Dell S3 (ECS).

As our AIP consist of multiple Fedora resources, we import these using transactions:

- POST the create a transaction
- Multiple PUTs to create new resources in Fedora
- PUT to commit the transaction

These ingests can happen in parallel, so it is possible to have multiple open transaction at the same time (each creating a different set of Fedora resources).
This generally works well, but we observed that when committing a large transaction (i.e. consisting of multiple large files), the other open transactions (even if they are much smaller) wait until the large transaction is finished.
So it seems to us that transactions are committed in a sequential manner.

Does somebody have similar experiences or knows if this is the expected behavior? It is not clear to me if this is a normal feature of the Fedora transaction mechanism or if it is connected to using S3 as a storage.

As the data transfer of individual files to S3 is rather slow, it would help if multiple transactions could happen in parallel, but I suspect currently one open transaction is executed after another.

Best regards

Basil