Hi Christophe,

Thanks for starting this proposal. It looks cool.

I'd suggest one real-world integration test you can make use of:
https://clickhouse.com/docs/en/integrations/kafka/kafka-connect-http
(replace source kafka with pulsar).

Best,
tison.


Enrico Olivelli <eolive...@gmail.com> 于2022年9月27日周二 18:04写道:

> Thanks for your answers.
> I am fine with the current proposal.
> We can enhance it as follow up work
>
> Enrico
>
> Il giorno ven 23 set 2022 alle ore 19:20 Christophe Bornet
> <bornet.ch...@gmail.com> ha scritto:
> >
> > Thanks for your feedback Enrico.
> > My answers to your comments below
> >
> > BR
> >
> > Christophe
> >
> > Le mar. 20 sept. 2022 à 14:16, Enrico Olivelli <eolive...@gmail.com> a
> > écrit :
> >
> > > Christophe,
> > > very good initiative!
> > >
> > > I support it
> > > Some comments inline below
> > >
> > >
> > > Enrico
> > >
> > > Il giorno lun 19 set 2022 alle ore 19:10 Christophe Bornet
> > > <bornet.ch...@gmail.com> ha scritto:
> > > >
> > > > Hi all,
> > > >
> > > > I have drafted PIP-208: HTTP Sink
> > > >
> > > > PIP link:
> > > > https://github.com/apache/pulsar/issues/17719
> > > >
> > > > Here's a copy of the contents of the GH issue for your references:
> > > >
> > > > ### Motivation
> > > >
> > > > Currently, when you want to consume from Pulsar topics in
> applications
> > > > written in languages that don't have a Pulsar driver supported, you
> need
> > > to
> > > > run some type of proxy like the WebSocket Proxy or Pulsar Beam. In
> > > > production this needs additional effort to deploy, scale, load
> balance,
> > > > monitor, and so on...
> > > > Pulsar IO is a framework that deals with all these operational
> subjects
> > > and
> > > > can be leveraged to provide a way to push messages to external
> systems
> > > > using HTTP, a protocol supported by every existing language and OS.
> > > >
> > > > ### Goal
> > > >
> > > > This proposal defines an HTTP Sink that sends the messages to a
> > > configured
> > > > URL.
> > > > It takes inspiration from [Pulsar Beam](
> > > > https://github.com/kafkaesque-io/pulsar-beam) and the [Confluent
> HTTP
> > > Sink
> > > > connector](
> > > >
> https://docs.confluent.io/kafka-connectors/http/current/overview.html).
> > > >
> > > >
> > > > ### Implementation
> > > >
> > > > A `pulsar-io-http` module will be added to `pulsar-io`.
> > > > On building the project `pulsar-io-http-{version}.nar` will be built
> and
> > > > added to the `pulsar-all` distribution.
> > > > The name of the Sink will be `http`.
> > > >
> > > > The HTTP Sink pushes records to any HTTP server with the record
> value in
> > > > the body of a POST method.
> > > > The body of the HTTP request is the JSON representation of the record
> > > value.
> > >
> > > What do you mean ?
> > > I think that this should depend on the Schema.
> > >
> > > BYTES SCHEMA -> I would push the raw message payload
> > > PRIMITIVE VALUES (long, integer, string) - > I would push the JSON
> > > represantation
> > > JSON SCHEMA ->  push the raw message payload
> > > AVRO -> ?  convert to JSON ?
> > > PROTOBUF -> ? convert to JSON ?
> > > KEY-VALUE ?
> > >
> > > Probably we need some flag to define the behaviour for the non trivial
> > > cases.
> > >
> > > The current impl chooses to serialize as JSON because it's a well
> > supported content-type on the server frameworks.
> > It's also to be consistent with existing HTTP Sinks such as Pulsar Bean
> and
> > Confluent HTTP Sink Connector.
> > The possibility to adapt the content-type to the schema is elegant and
> will
> > probably result in shorter payloads (but less readable) and I think it
> > could be done as a follow-up option.
> > It has indeed the problem of being difficult to do for KV schema.
> > For the content-type mappings I would do:
> > BYTES SCHEMA -> application/octet-stream (raw bytes)
> > PRIMITIVE VALUES (long, integer, string) - > text/plain
> > JSON ->  application/json
> > AVRO -> avro/binary
> > PROTOBUF -> probably application/octet-stream ?
> > KEY-VALUE ?
> >
> > Would also need to indicate the Schema-Type in the HTTP headers.
> >
> >
> > >
> > > >
> > > > Some headers are added to the HTTP request:
> > > > * `PulsarTopic`: the topic of the record
> > > > * `PulsarKey`: the key of the record
> > > > * `PulsarEventTime`: the event time of the record
> > > > * `PulsarPublishTime`: the publish time of the record
> > > > * `PulsarMessageId`: the ID of the message contained in the record
> > > > * `PulsarProperties-*`: each record property is passed with the
> property
> > > > name prefixed by `PulsarProperties-`
> > > >
> > >
> > > Can we make the "Content-Type" configurable ?
> > >
> > Yes we can. But do we do it for the first iteration ?
> > If we do it, I would have an option to add some fix headers and the user
> > can override the content-type.
> > If we go for a variable content-type depending on the schema, then we
> could
> > have a map<SchemaType, content-type>
> >
> > > Can we make the HTTP METHOD configurable ?
> > >
> > Yes we can. But do we do it for the first iteration ?
> >
> > >
> > > > ### Alternatives
> > > >
> > > > Creating a separated project for this Sink is rejected since:
> > > > * this Sink is very useful for developers to test the Pulsar IO
> > > framework,
> > > > transform functions, and to make demos.
> > > > * the code has a very small footprint with no external dependencies.
> > > > * it should be visible at the same level as other sinks
> > >
> > > 100% agreed !
> > >
> > > >
> > > > I'm looking forward the discussion.
> > > >
> > > > Best regards,
> > > >
> > > > Christophe Bornet
> > >
>

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