2022 HDF5 Release Schedule
Dana Robinson (Email)
Hi everyone! I’m Dana Robinson and I’m the Director of Engineering at The HDF Group. I’ve been with the company since 2009 so many of you may already know me. In an effort to increase transparency at The HDF Group, I’m going to try to blog more frequently so that everyone is more aware of what’s going on at the company and with our products.
Today I’d like to talk about our upcoming release schedule. As some of you may already have noticed, we now post the current HDF5 release schedule in the README.md document in the project’s root on GitHub. I’ll update this as circumstances change so it always reflects our current thinking.
Here’s the current schedule, which is being propagated to the HDF5 maintenance branches:
And the features we intend to release in each version of HDF5 1.13.x (also listed in the GitHub README.md file):
- HDF5 1.13.2: Selection I/O, VFD SWMR, Onion VFD
- HDF5 1.13.3: Multi-dataset I/O, Subfiling
HDF5 1.8.23, to be released in December 2022, will probably be the last release of the 1.8 maintenance branch. We’ve implemented several performance improvements to HDF5 1.10+ that bring it much closer to HDF5 1.8’s performance and we hope to finish off that work over the summer.
HDF5 1.10.9 released last month and that is the last planned release of HDF5 1.10 until spring of next year. If the performance improvements I plan for the summer are compelling enough, we’ll think about doing another 1.10 release in the fall. I anticipate this branch living on throughout 2023, given the imminent demise of 1.12 and how new 1.14 will be (see below).
This maintenance line will be retired shortly after HDF5 1.14.0 is released. We had to make changes to the VOL class struct in 1.13 that break binary compatibility and therefore these can’t be pushed back to the 1.12 maintenance line. All new VOL development should be targeting 1.13 (i.e., the develop branch).
HDF5 1.13 / 1.14
HDF5 1.13 will have two more releases as we prep for the HDF5 1.14.0 release at the end of the year. The major new features will be selection I/O, subfiling, multi-dataset I/O, VFD SWMR, and the onion VFD. I’ll have separate posts for each of these features over the next month or three. As mentioned in a previous blog post, HDF5 1.13.x are experimental releases where the API and file format can change. These are produced directly from the develop branch in GitHub. At the end of the year, we will create an hdf5_1_14 branch, release 1.14.0 out of that, and develop will be updated to 1.15.
This month, I changed the 1.13.x release schedule:
- HDF5 1.13.2 will release in July of this year instead of June. The onion VFD and VFD SWMR required more integration work than anticipated, so we had to move this back a month.
- HDF5 1.13.3 has been moved back a month to September and combined with HDF5 1.13.4 (which is thus moved up a month). This was prompted by the move of HDF5 1.13.2 and not development problems with either the subfiling or multi-dataset I/O features.
Hopefully, this will put us on track to reduce the plethora of branches we maintain, which will be less confusing for users and less maintenance work on our end.