Agreed that it makes sense not to focus on in-place updating for this proposal. I’m not even sure it’s a great fit as a “general purpose” Arrow protocol, because of all the assumptions and restrictions required as you noted.
I took another look at the proposal and don’t think there’s anything preventing in-place updating in the future - ultimately the data body could just be in the same location for subsequent messages. Thanks! Paul On Fri, Mar 1, 2024 at 5:28 PM Matt Topol <zotthewiz...@gmail.com> wrote: > > @pgwhalen: As a potential "end user developer," (and aspiring > contributor) this > immediately excited me when I first saw it. > > Yay! Good to hear that! > > > @pgwhalen: And it wasn't clear to me whether updating batches in > place (and the producer/consumer coordination that comes with that) was > supported or encouraged as part of the proposal. > > So, updating batches in place was not a particular use-case we were > targeting with this approach. Instead using shared memory to produce and > consume the buffers/batches without having to physically copy the data. > Trying to update a batch in place is a dangerous prospect for a number of > reasons, but as you've mentioned it can technically be made safe if the > shape is staying the same and you're only modifying fixed-width data types > (i.e. not only is the *shape* unchanged but the sizes of the underlying > data buffers are also remaining unchanged). The producer/consumer > coordination that would be needed for updating batches in place is not part > of this proposal but is definitely something we can look into as a > follow-up to this for extending it. There's a number of discussions that > would need to be had around that so I don't want to add on another > complexity to this already complex proposal. > > That said, if you or anyone see something in this proposal that would > hinder or prevent being able to use it for your use case please let me know > so we can address it. Even though the proposal as it currently exists > doesn't fully support the in-place updating of batches, I don't want to > make things harder for us in such a follow-up where we'd end up requiring > an entirely new protocol to support that. > > > @octalene.dev: I know of a third party that is interested in Arrow for > HPC environments that could be interested in the proposal and I can see if > they're interested in providing feedback. > > Awesome! Thanks much! > > > For reference to anyone who hasn't looked at the document in a while, since > the original discussion thread on this I have added a full "Background > Context" page to the beginning of the proposal to help anyone who isn't > already familiar with the issues this protocol is trying to solve or isn't > already familiar with ucx or libfabric transports to better understand > *why* I'm > proposing this and what it is trying to solve. The point of this background > information is to help ensure that anyone who might have thoughts on > protocols in general or APIs should still be able to understand the base > reasons and goals that we're trying to achieve with this protocol proposal. > You don't need to already understand managing GPU/device memory or ucx to > be able to have meaningful input on the document. > > Thanks again to all who have contributed so far and please spread to any > contacts that you think might be interested in this for their particular > use cases. > > --Matt > > On Wed, Feb 28, 2024 at 1:39 AM Aldrin <octalene....@pm.me.invalid> wrote: > > > I am interested in this as well, but I haven't gotten to a point where I > > can have valuable input (I haven't tried other transports). I know of a > > third party that is interested in Arrow for HPC environments that could > be > > interested in the proposal and I can see if they're interested in > providing > > feedback. > > > > I glanced at the document before but I'll go through again to see if > there > > is anything I can comment on. > > > > > > > > # ------------------------------ > > # Aldrin > > > > > > https://github.com/drin/ > > https://gitlab.com/octalene > > https://keybase.io/octalene > > > > > > On Tuesday, February 27th, 2024 at 17:43, Paul Whalen < > pgwha...@gmail.com> > > wrote: > > > > > As a potential "end user developer," (and aspiring contributor) this > > > immediately excited me when I first saw it. > > > > > > > > I work at a trading firm, and my team has developed an IPC mechanism > for > > > efficiently transmitting pandas dataframes both remotely via TCP and > > > locally via shared memory, where the interface for the application > > > developer is the same for both. The data in the dataframes may change > > > rapidly, so when communicating locally via shared memory, if the shape > of > > > the dataframe doesn't change, we update the memory in place, > coordinating > > > between the producer and consumer via TCP. > > > > > > > > We intend to move away from our remote TCP mechanism towards Arrow > > Flight, > > > or a lighter-weight version of Arrow IPC. For the local shared memory > > > mechanism which we previously did not have a good answer for, it seems > > like > > > Disassociated Arrow IPC maps quite well to our problem. > > > > > > > > So some features that enable our use case are: > > > - Updating existing batches in place is supported > > > - The interface is pretty similar to Flight > > > > > > > > I'd imagine we're not the only financial firm to implement something > like > > > this, given how widespread pandas usage is, so that could be a place to > > > seek feedback. > > > > > > > > As I was reading the proposal initially, I gleaned that the most > > important > > > audience was those writing interfaces to GPUs/remote > memory/non-standard > > > transports/etc. And it wasn't clear to me whether updating batches in > > > place (and the producer/consumer coordination that comes with that) was > > > supported or encouraged as part of the proposal. But regardless, as an > > end > > > user, this seems like an easier and more efficient way to glue pieces > in > > > the Arrow ecosystem together if it was adopted broadly. > > > > > > > > Paul > > > > > > > > On Tue, Feb 27, 2024 at 6:05 PM Matt Topol zotthewiz...@gmail.com > wrote: > > > > > > > > > I'll continue my efforts of trying to reach out to other interested > > > > parties, but if anyone else here has any contacts or connections that > > they > > > > think might be interested please forward them the link to the Google > > doc. > > > > > > > > > > I really do want to get as much engagement and feedback as possible > on > > > > this. > > > > > > > > > > Thanks! > > > > > > > > > > On Tue, Feb 27, 2024, 6:38 PM Wes McKinney wesmck...@gmail.com > wrote: > > > > > > > > > > > Have there been efforts to proactively reach out to other third > > parties > > > > > that might have an interest in this or be a potential user at some > > point? > > > > > There are a lot of interested parties in Arrow that may not > actively > > > > > follow > > > > > the mailing list. > > > > > > > > > > > > Seems like folks from the Dask, Ray, RAPIDS (especially folks at > > NVIDIA > > > > > or > > > > > working on UCX), or other communities like that might have > > constructive > > > > > thoughts about this. DLPack (https://dmlc.github.io/dlpack/latest/ > ) > > also > > > > > seems adjacent and worth reaching out to. Other ideas for projects > or > > > > > companies that could be reached out to for feedback. > > > > > > > > > > > > On Tue, Feb 27, 2024 at 5:23 PM Antoine Pitrou anto...@python.org > > > > > wrote: > > > > > > > > > > > > > If there's no engagement, then I'm afraid it might mean that > third > > > > > > parties have no interest in this. I don't really have any > solution > > for > > > > > > generating engagement except nagging and pinging people > explicitly > > :-) > > > > > > > > > > > > > > Le 27/02/2024 à 19:09, Matt Topol a écrit : > > > > > > > > > > > > > > > I would like to see the same Antoine, currently given the lack > of > > > > > > > engagement (both for OR against) I was going to take the > silence > > as > > > > > > > assent > > > > > > > and hope for non-Voltron Data PMC members to vote in this. > > > > > > > > > > > > > > > > If anyone has any suggestions on how we could potentially > > generate > > > > > > > more > > > > > > > engagement and discussion on this, please let me know as I want > > as > > > > > > > many > > > > > > > parties in the community as possible to be part of this. > > > > > > > > > > > > > > > > Thanks everyone. > > > > > > > > > > > > > > > > --Matt > > > > > > > > > > > > > > > > On Tue, Feb 27, 2024 at 12:48 PM Antoine Pitrou > > anto...@python.org > > > > > > > wrote: > > > > > > > > > > > > > > > > > Hello, > > > > > > > > > > > > > > > > > > I'd really like to see more engagement and criticism from > > > > > > > > non-Voltron > > > > > > > > Data parties before this is formally adopted as an Arrow > spec. > > > > > > > > > > > > > > > > > > Regards > > > > > > > > > > > > > > > > > > Antoine. > > > > > > > > > > > > > > > > > > Le 27/02/2024 à 18:35, Matt Topol a écrit : > > > > > > > > > > > > > > > > > > > Hey all, > > > > > > > > > > > > > > > > > > > > I'd like to propose a vote for us to officially adopt the > > protocol > > > > > > > > > described in the google doc[1] for Dissociated Arrow IPC > > > > > > > > > Transports. > > > > > > > > > This > > > > > > > > > proposal was originally discussed at 2. Once this proposal > is > > > > > > > > > adopted, > > > > > > > > > I > > > > > > > > > will work on adding the necessary documentation to the > Arrow > > > > > > > > > website > > > > > > > > > along > > > > > > > > > with examples etc. > > > > > > > > > > > > > > > > > > > > The vote will be open for at least 72 hours. > > > > > > > > > > > > > > > > > > > > [ ] +1 Accept this Proposal > > > > > > > > > [ ] +0 > > > > > > > > > [ ] -1 Do not accept this proposal because... > > > > > > > > > > > > > > > > > > > > Thank you everyone! > > > > > > > > > > > > > > > > > > > > --Matt > > > > > > > > > > > > > > > > > > > > [1]: > > > > > > > > > > > > > https://docs.google.com/document/d/1zHbnyK1r6KHpMOtEdIg1EZKNzHx-MVgUMOzB87GuXyk/edit#heading=h.38515dnp2bdb >
