Il giorno lun 8 nov 2021 alle ore 15:01 ZhangJian He <shoot...@gmail.com>
ha scritto:
> Hello, matteo, About my PIP 108, the reason I want to have method
> `hasMessageInReceiverQueue` is that
> We need to control consumer at different rate. For example, consumer A
> 10msg/s, consumer B 100 msg/s
> so I can't use the `listener` mode.
> the `receive(0)` method will remove the message from queue. currently my
> work flow is 1) check if has message
> 2) apply for flow quota 3) receive messages. I can not put the mssage back
> to the queue, can't use the `receive(0)`.
> And `apply for flow quota` is a costly action.
> And discussed with PengHui Li and Hang Chen, we think `hasLocalMessages` is
> better than hasMessageInReceiverQueue
>
"hasLocalMessages" works for me
Enrico
>
> ZhangJian He <shoot...@gmail.com> 于2021年10月27日周三 下午7:47写道：
>
> > Some users want to use this api to judge if there's messages to receive,
> > like that pseudo code:
> > if (consumer.hasMessage()) {
> > .submit(() -> {
> > consumer.pollMessagesAccordingToTheDistributedFlowControl()
> > })
> > }
> >
> > don't want to remove the message from queue.
> >
> > PengHui Li <peng...@apache.org> 于2021年10月27日周三 下午7:43写道：
> >
> >> @ZhangJian He, as Matteo mentioned, Use `consumer.receive(0,
> >> TimeUnit.SECONDS)` can achieve the same purpose for checking if there
> are
> >> messages in the local cache.
> >>
> >> Thanks
> >> Penghui
> >>
> >> On Tue, Oct 26, 2021 at 2:35 PM ZhangJian He <shoot...@gmail.com>
> wrote:
> >>
> >> > If some users need the message content to do user-defined actions, we
> >> need
> >> > to ensure the user can't use the `peekMessage` to do things like ack
> >> > because the message are still in the blockingQueue, return just a
> >> > content-copy?
> >> >
> >> > introduced `localBuffer` might be good ? `hasMessagesInLocalBuffer`
> >> >
> >> > JiangHaiting <jianghait...@foxmail.com> 于2021年10月26日周二 下午2:20写道：
> >> >
> >> > > I'm totally +1 for the feature to check if we can get
> >> > > message immediately from consumer, this is to say we have
> message
> >> > > locally.
> >> > >
> >> > >
> >> > > In my understanding, it's useful to implement some user-defined
> order
> >> to
> >> > > consume messages among different topics, in your case, the
> >> "distributed
> >> > > flow control ability".
> >> > > But in the past few years, I've met some users have defined the
> >> consume
> >> > > order of different topics by part of the message content, like
> >> > > some critical property value.
> >> > > In these situations, a `peek` method is more suitable.
> >> > >
> >> > >
> >> > > Further more, peek is not effectively equals to `consumer.receive(0,
> >> > > TimeUnit.SECONDS)`. As you will have to store the message somewhere
> >> else
> >> > if
> >> > > you find that it's not the most priority message to process.
> >> > >
> >> > >
> >> > > One last thing, put the concept of "receiverQueue" in the api of
> >> > consumer,
> >> > > seems a little bit strange, IMHO.
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > ------------------ Original ------------------
> >> > > From:
> >> > > "dev"
> >> > > <
> >> > > shoot...@gmail.com>;
> >> > > Date: Tue, Oct 26, 2021 12:54 PM
> >> > > To: "dev"<dev@pulsar.apache.org>;
> >> > >
> >> > > Subject: Re: [DISCUSSION] PIP-108: Add method to help user
> judge
> >> if
> >> > > consumer queue has message
> >> > >
> >> > >
> >> > >
> >> > > 3. Our solution implements the distributed flow control ability at
> >> client
> >> > > side, so we don't use the listener way.
> >> > > 2. Per customer per consumer in different tenants and namespace, and
> >> the
> >> > > `flow-control` need(Some of our customer's machines can't work on
> high
> >> > > traffic), So `Multi-topic` can't use.
> >> > > 1. We want to use this api to judge if there's messages to receive,
> >> like
> >> > > that pseudo code
> >> > > if (consumer.hasMessage()) {
> >> > > .submit(() -> {
> >> > > consumer.pollMessagesAccordingToTheDistributedFlowControl()
> >> > > })
> >> > > }
> >> > >
> >> > > Matteo Merli <matteo.me...@gmail.com> 于2021年10月26日周二 下午12:15写道：
> >> > >
> >> > > > I'm a bit hesitant about this because I think there are already
> >> at
> >> > > > least 3 different ways to handle similar scenarios.
> >> > > >
> >> > > > 1. Using listener and avoid calling receive directly
> >> > > > 2. Use multi-topic consumer, so there's a single
> `Consumer`
> >> > > instance
> >> > > > exposed
> >> > > > 3. Use `consumer.receive(0, TimeUnit.SECONDS)` to probe
> for
> >> > > message
> >> > > >
> >> > > >
> >> > > > --
> >> > > > Matteo Merli
> >> > > > <matteo.me...@gmail.com>
> >> > > >
> >> > > > On Mon, Oct 25, 2021 at 7:34 PM ZhangJian He <
> shoot...@gmail.com
> >> > >
> >> > > wrote:
> >> > > > >
> >> > > > > I think it's better to add the method to Consumer
> interface
> >> > > instead of
> >> > > > let
> >> > > > > user casting it to `ConsumerBase`.
> >> > > > > `peek` is most complexly, for the reason, I can use
> >> the
> >> > > `peek` object to
> >> > > > > ack、negative ack, but when to remove from the
> >> `BlockingQueue`?
> >> > > > > IMHO, people use this api are just to judge if has the
> >> message,
> >> > > > otherwise,
> >> > > > > they can just use `receive(0,TimeUnit)
> >> > > > >
> >> > > > > JiangHaiting <jianghait...@foxmail.com> 于2021年10月26日周二
> >> > > 上午10:19写道：
> >> > > > >
> >> > > > > > Can this method
> >> > > > > >
> >> > >
> "org.apache.pulsar.client.impl.ConsumerBase#getTotalIncomingMessages"
> >> > > > do
> >> > > > > > the trick? Though you have to change the type to
> >> > > ConsumerBase.
> >> > > > > >
> >> > > > > >
> >> > > > > > And maybe `peek` is more suitable and useful to add
> to
> >> the
> >> > > Consumer
> >> > > > > > interface？
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > ------------------&nbsp;Original&nbsp;------------------
> >> > > > > > From:
> >> > > > >
> >> > >
> >> >
> >>
> >
> >> > > "dev"
> >> > > > >
> >> > >
> >> >
> >>
> >
> >> > > <
> >> > > > > > shoot...@gmail.com&gt;;
> >> > > > > > Date:&nbsp;Mon, Oct 25, 2021 07:24 PM
> >> > > > > > To:&nbsp;"dev"<dev@pulsar.apache.org&gt;;
> >> > > > > >
> >> > > > > > Subject:&nbsp;[DISCUSSION] PIP-108: Add method to
> >> help
> >> > > user judge if
> >> > > > > > consumer queue has message
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > > https://github.com/apache/pulsar/issues/12479
> >> > > > > >
> >> > > > > > --- Pasted here for quoting convenience ---
> >> > > > > >
> >> > > > > > ## Motivation
> >> > > > > > Currently, I have an application that manages ten
> >> thousand
> >> > > of
> >> > > > consumers,
> >> > > > > > and a logic to schedule consumers's receive. It would
> >> be
> >> > > helpful to
> >> > > > know if
> >> > > > > > one of the consumers have message to recive.
> >> > > > > >
> >> > > > > > ## Goal
> >> > > > > > To make `Consumer` can judge if there are unreceiving
> >> > > messages
> >> > > > > >
> >> > > > > > ## API Changes
> >> > > > > >
> >> > > > > > Add `hasMessageInReceiverQueue` on the `Consumer`
> >> > interface.
> >> > > > > >
> >> > > > > > ## Implementation
> >> > > > > >
> >> > > > > > For `ZeroQueueConsumerImpl` return false, Others,
> judge
> >> > the
> >> > > > > > `receiveQueueSize` greater than zero.
> >> > > > > >
> >> > > > > >
> >> > > > > > ## Reject Alternatives
> >> > > > > >
> >> > > > > > No alternatives yet.
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > > ---
> >> > > > > > Thanks,
> >> > > > > > Haiting Jiang (Github: Jason918)
> >> > > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > ---
> >> > > Thanks,
> >> > > Haiting Jiang (Github: Jason918)
> >> >
> >>
> >
>
