+1
On Tue, Feb 27, 2024 at 9:06 AM David Li <lidav...@apache.org> wrote: > I would like to propose a 'reuse connection' URI scheme for Flight RPC. > This proposal was previously discussed at [1]. A candidate implementation > for C++, Java, and Go is at [2]. > > The vote will be open for at least 72 hours. > > [ ] +1 > [ ] +0 > [ ] -1 Do not accept this proposal because... > > [1]: https://lists.apache.org/thread/pc9fs0hf8t5ylj9os00r9vg8d2xv2npz > [2]: https://github.com/apache/arrow/pull/40084 > > On Tue, Feb 20, 2024, at 14:14, David Li wrote: > > Thanks for the comments - I've updated the implementation [1] and added > > Go + integration tests. If this all checks out I'd like to start a vote > > soon. > > > > [1]: https://github.com/apache/arrow/pull/40084 > > > > On Fri, Feb 16, 2024, at 13:43, Andrew Lamb wrote: > >> Thank you -- I think the usecase is great, but agree with the other > >> reviewers that the name may be confusing. I left some notes on the > ticket > >> > >> Andrew > >> > >> On Wed, Feb 14, 2024 at 3:52 PM David Li <lidav...@apache.org> wrote: > >> > >>> I've put up a candidate implementation sans integration test [1]. > >>> > >>> Some caveats: > >>> - java.net.URI doesn't accept 'scheme://', only 'scheme:/' or > 'scheme://?' > >>> (yes, an empty query string pacifies it). I've chosen the latter since > the > >>> former is technically a URI with a non-empty path but neither are > ideal. > >>> - I've changed the scheme to 'arrow-flight-reuse-connection' to be more > >>> faithful to the intended use than 'fallback'. > >>> > >>> [1]: https://github.com/apache/arrow/pull/40084 > >>> > >>> On Tue, Feb 13, 2024, at 13:01, Jean-Baptiste Onofré wrote: > >>> > Hi David, > >>> > > >>> > It's reasonable. I think we can start with your initial proposal (it > >>> > sounds fine to me) and we can always improve step by step. > >>> > > >>> > Thanks ! > >>> > Regards > >>> > JB > >>> > > >>> > On Tue, Feb 13, 2024 at 4:53 PM David Li <lidav...@apache.org> > wrote: > >>> >> > >>> >> I'm going to keep the proposal as-is then. It can be extended if > this > >>> use case comes up. > >>> >> > >>> >> I'll start work on candidate implementations now. > >>> >> > >>> >> On Tue, Feb 13, 2024, at 03:22, Antoine Pitrou wrote: > >>> >> > I think the original proposal is sufficient. > >>> >> > > >>> >> > Also, it is not obvious to me how one would switch from e.g. > grpc+tls > >>> to > >>> >> > http without an explicit server location (unless both Flight > servers > >>> are > >>> >> > hosted under the same port?). So the "+" proposal seems a bit > weird. > >>> >> > > >>> >> > > >>> >> > Le 12/02/2024 à 23:39, David Li a écrit : > >>> >> >> The idea is that the client would reuse the existing connection, > in > >>> which case the protocol and such are implicit. (If the client doesn't > have > >>> a connection anymore, it can't use the fallback anyways.) > >>> >> >> > >>> >> >> I suppose this has the advantage that you could "fall back" to a > >>> known hostname with a different protocol, but I'm not sure that always > >>> applies anyways. (Correct me if I'm wrong Matt, but as I recall, UCX > >>> addresses aren't hostnames but rather opaque byte blobs, for instance.) > >>> >> >> > >>> >> >> If we do prefer this, to avoid overloading the hostname, there's > >>> also the informal convention of using + in the scheme, so it could be > >>> arrow-flight-fallback+grpc+tls://, arrow-flight-fallback+http://, etc. > >>> >> >> > >>> >> >> On Mon, Feb 12, 2024, at 17:03, Joel Lubinitsky wrote: > >>> >> >>> Thanks for clarifying. > >>> >> >>> > >>> >> >>> Given the relationship between these two proposals, would it > also be > >>> >> >>> necessary to distinguish the scheme (or schemes) supported by > the > >>> >> >>> originating Flight RPC service? > >>> >> >>> > >>> >> >>> If that is the case, it may be preferred to use the "host" > portion > >>> of the > >>> >> >>> URI rather than the "scheme" to denote the location of the > data. In > >>> this > >>> >> >>> scenario, the host "0.0.0.0" could be used. This IP address is > >>> defined in > >>> >> >>> IETF RFC1122 [1] as "This host on this network", which seems > most > >>> >> >>> consistent with the intended use-case. There are some caveats to > >>> this usage > >>> >> >>> but in my experience it's not uncommon for protocols to extend > the > >>> >> >>> definition of this address in their own usage. > >>> >> >>> > >>> >> >>> A benefit of this convention is that the scheme remains > available > >>> in the > >>> >> >>> URI to specify the transport available. For example, the > following > >>> list of > >>> >> >>> locations may be included in the response: > >>> >> >>> > >>> >> >>> ["grpc://0.0.0.0", "ucx://0.0.0.0", "grpc://1.2.3.4", > >>> <other_locations>...] > >>> >> >>> > >>> >> >>> This would indicate that grpc and ucx transport is available > from > >>> the > >>> >> >>> current service, grpc is available at 1.2.3.4, and possibly more > >>> >> >>> combinations of scheme/host. > >>> >> >>> > >>> >> >>> [1] > https://datatracker.ietf.org/doc/html/rfc1122#section-3.2.1.3 > >>> >> >>> > >>> >> >>> On Mon, Feb 12, 2024 at 2:53 PM David Li <lidav...@apache.org> > >>> wrote: > >>> >> >>> > >>> >> >>>> Ah, while I was thinking of it as useful for a fallback, I'm > not > >>> >> >>>> specifying it that way. Better ideas for names would be > >>> appreciated. > >>> >> >>>> > >>> >> >>>> The actual precedence has never been specified. All endpoints > are > >>> >> >>>> equivalent, so clients may use what is "best". For instance, > with > >>> Matt > >>> >> >>>> Topol's concurrent proposal, a GPU-enabled client may > >>> preferentially try > >>> >> >>>> UCX endpoints while other clients may choose to ignore them > >>> entirely (e.g. > >>> >> >>>> because they don't have UCX installed). > >>> >> >>>> > >>> >> >>>> In practice the ADBC/JDBC drivers just scan the list left to > right > >>> and try > >>> >> >>>> each endpoint in turn for lack of a better heuristic. > >>> >> >>>> > >>> >> >>>> On Mon, Feb 12, 2024, at 14:28, Joel Lubinitsky wrote: > >>> >> >>>>> Thanks for proposing this David. > >>> >> >>>>> > >>> >> >>>>> I think the ability to include the Flight RPC service itself > in > >>> the list > >>> >> >>>> of > >>> >> >>>>> endpoints from which data can be fetched is a helpful > addition. > >>> >> >>>>> > >>> >> >>>>> The current choice of name for the URI > (arrow-flight-fallback://) > >>> seems > >>> >> >>>> to > >>> >> >>>>> imply that there is an order of precedence that should be > >>> considered in > >>> >> >>>> the > >>> >> >>>>> list of URI’s. Specifically, as a developer receiving the > list of > >>> >> >>>> locations > >>> >> >>>>> I might assume that I should try fetching from other locations > >>> first. If > >>> >> >>>>> those do not succeed, I may try the original service as a > >>> fallback. > >>> >> >>>>> > >>> >> >>>>> Are these the intended semantics? If so, is there a way to > >>> include the > >>> >> >>>>> original service in the list of locations without the implied > >>> precedence? > >>> >> >>>>> > >>> >> >>>>> Thanks, > >>> >> >>>>> Joel > >>> >> >>>>> > >>> >> >>>>> On Mon, Feb 12, 2024 at 11:52 James Duong < > >>> james.du...@improving.com > >>> >> >>>> .invalid> > >>> >> >>>>> wrote: > >>> >> >>>>> > >>> >> >>>>>> This seems like a good idea, and also improves consistency > with > >>> clients > >>> >> >>>>>> that erroneously assumed that the service endpoint was > always in > >>> the > >>> >> >>>> list > >>> >> >>>>>> of endpoints. > >>> >> >>>>>> > >>> >> >>>>>> From: Antoine Pitrou <anto...@python.org> > >>> >> >>>>>> Date: Monday, February 12, 2024 at 6:05 AM > >>> >> >>>>>> To: dev@arrow.apache.org <dev@arrow.apache.org> > >>> >> >>>>>> Subject: Re: [DISCUSS] Flight RPC: add 'fallback' URI scheme > >>> >> >>>>>> > >>> >> >>>>>> Hello, > >>> >> >>>>>> > >>> >> >>>>>> This looks fine to me. > >>> >> >>>>>> > >>> >> >>>>>> Regards > >>> >> >>>>>> > >>> >> >>>>>> Antoine. > >>> >> >>>>>> > >>> >> >>>>>> > >>> >> >>>>>> Le 12/02/2024 à 14:46, David Li a écrit : > >>> >> >>>>>>> Hello, > >>> >> >>>>>>> > >>> >> >>>>>>> I'd like to propose a slight update to Flight RPC to make > >>> Flight SQL > >>> >> >>>>>> work better in different deployment scenarios. Comments on > the > >>> doc > >>> >> >>>> would > >>> >> >>>>>> be appreciated: > >>> >> >>>>>>> > >>> >> >>>>>>> > >>> >> >>>>>> > >>> >> >>>> > >>> > https://docs.google.com/document/d/1g9M9FmsZhkewlT1mLibuceQO8ugI0-fqumVAXKFjVGg/edit?usp=sharing > >>> >> >>>>>>> > >>> >> >>>>>>> The gist is that FlightEndpoint allows specifying either > (1) a > >>> list of > >>> >> >>>>>> concrete URIs to fetch data from or (2) no URIs, meaning to > >>> fetch from > >>> >> >>>> the > >>> >> >>>>>> Flight RPC service itself; but it would be useful to combine > both > >>> >> >>>> behaviors > >>> >> >>>>>> (try these concrete URIs and fall back to the Flight RPC > service > >>> itself) > >>> >> >>>>>> without requiring the service to know its own public address. > >>> >> >>>>>>> > >>> >> >>>>>>> Best, > >>> >> >>>>>>> David > >>> >> >>>>>> > >>> >> >>>> > >>> >
