Hi David,
Thanks for the comment.
I've updated the KIP, to add the method will be added into `Subscription`
class:
// new added, the generationId getter
public int generationId() {
return generationId;
}
Thank you.
Luke
On Mon, Feb 21, 2022 at 5:24 PM David Jacot <dja...@confluent.io.invalid>
wrote:
> Hi Luke,
>
> I apologize for my late reply. I was out for a while.
>
> Coming back to my previous point, could you also
> spell out the new method(s) that we need to add to
> the Subscription class?
>
> Thanks,
> David
>
> On Mon, Feb 14, 2022 at 6:28 PM Guozhang Wang <wangg...@gmail.com> wrote:
> >
> > Thanks Luke, no more comments from me, nice work!
> >
> > On Mon, Feb 14, 2022 at 5:22 AM Luke Chen <show...@gmail.com> wrote:
> >
> > > Hi Guozhang,
> > >
> > > Thanks for your comments. I've updated the KIP.
> > > Here's what I've updated:
> > >
> > > * In the motivation section, I've added this paragraph after
> > > cooperativeStickyAssignor like this:
> > >
> > > *On the other hand, `StickyAssignor` is also adding "generation" field
> > > plus the "ownedPartitions" into subscription userData bytes. the
> difference
> > > is that the `StickyAssignor`'s user bytes also encode the prev-owned
> > > partitions while the `CooperativeStickyAssignor` relies on the
> prev-owned
> > > partitions on the subscription protocol directly.*
> > >
> > > * In the proposed change section, I've updated the paragraph as:
> > >
> > >
> > > *For built-in CooperativeStickyAssignor, if there are consumers in old
> > > bytecode and some in the new bytecode, it's totally fine, because the
> > > subscription data from old consumers will contain \[empty
> ownedPartitions +
> > > default generation(-1)] in V0, or \[current ownedPartitions + default
> > > generation(-1)] in V1. For V0 case, it's quite simple, because we'll
> just
> > > ignore the info since they are empty. For V1 case, we'll get the
> > > "ownedPartitions" data, and then decode the "generation" info in the
> > > subscription userData bytes. So that we can continue to do assignment
> with
> > > these information.*
> > > * Also, after the "cooperativeStickyAssignor paragraph, I've also
> mentioned
> > > stickyAssignor:
> > >
> > >
> > > *For built-in StickyAssignor, if there are consumers in old bytecode
> and
> > > some in the new bytecode, it's also fine, because the subscription data
> > > from old consumers will contain \[empty ownedPartitions + default
> > > generation(-1)] in V0, or \[current ownedPartitions + default
> > > generation(-1)] in V1. For both V0 and V1 case, we'll directly use the
> > > ownedPartition and generation info in the subscription userData bytes.
> *
> > >
> > > Please let me know if you have other comments.
> > >
> > > Thank you.
> > > Luke
> > >
> > > On Wed, Feb 9, 2022 at 2:57 PM Guozhang Wang <wangg...@gmail.com>
> wrote:
> > >
> > > > Hello Luke,
> > > >
> > > > Thanks for the updated KIP, I've taken a look at it and still LGTM.
> Just
> > > a
> > > > couple minor comments in the wiki:
> > > >
> > > > * Both `StickyAssignor` and `CooperativeStickyAssignor` that there's
> > > > already generation is encoded in user-data bytes, the difference is
> that
> > > > the `StickyAssignor`'s user bytes also encode the prev-owned
> partitions
> > > > while the `CooperativeStickyAssignor` relies on the prev-owned
> partitions
> > > > on the subscription protocol directly. So we can add the
> `StickyAssignor`
> > > > in your paragraph talking about `CooperativeStickyAssignor` as well.
> > > >
> > > > * This sentence: "otherwise, we'll take the ownedPartitions as
> default
> > > > generation(-1)." does not read right to me, maybe need to rephrase a
> bit?
> > > >
> > > >
> > > > Guozhang
> > > >
> > > > On Mon, Feb 7, 2022 at 7:36 PM Luke Chen <show...@gmail.com> wrote:
> > > >
> > > > > Hi David,
> > > > >
> > > > > Thanks for your comments.
> > > > > I've updated the KIP to add changes in Subscription class.
> > > > >
> > > > > Thank you.
> > > > > Luke
> > > > >
> > > > > On Fri, Feb 4, 2022 at 11:43 PM David Jacot
> > > <dja...@confluent.io.invalid
> > > > >
> > > > > wrote:
> > > > >
> > > > > > Hi Luke,
> > > > > >
> > > > > > Thanks for updating the KIP. I just have a minor request.
> > > > > > Could you fully describe the changes to the Subscription
> > > > > > public class in the KIP? I think that it would be better than
> > > > > > just saying that the generation will be added to id.
> > > > > >
> > > > > > Otherwise, the KIP LGTM.
> > > > > >
> > > > > > Thanks,
> > > > > > David
> > > > > >
> > > > > > On Mon, Nov 29, 2021 at 4:29 AM Luke Chen <show...@gmail.com>
> wrote:
> > > > > > >
> > > > > > > Hi devs,
> > > > > > > Welcome to provide feedback.
> > > > > > >
> > > > > > > If there are no other comments, I'll start a vote tomorrow.
> > > > > > >
> > > > > > > Thank you.
> > > > > > > Luke
> > > > > > >
> > > > > > >
> > > > > > > On Mon, Nov 22, 2021 at 4:16 PM Luke Chen <show...@gmail.com>
> > > wrote:
> > > > > > >
> > > > > > > > Hello David,
> > > > > > > >
> > > > > > > > For (3):
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > * I suppose that we could add a `generation` field to the
> > > > > > JoinGroupRequest
> > > > > > > > instead to do the fencing that you describe while handling
> the
> > > > > > sentinel in
> > > > > > > > the assignor directly. If we would add the `generation` to
> the
> > > > > request
> > > > > > > > itself, would we need the `generation` in the subscription
> > > protocol
> > > > > as
> > > > > > > > well?*
> > > > > > > >
> > > > > > > > On second thought, I think this is not better than adding
> > > > > `generation`
> > > > > > > > field in the subscription protocol, because I think we don't
> have
> > > > to
> > > > > > do any
> > > > > > > > generation validation on joinGroup request. The purpose of
> > > > > > > > `joinGroupRequest` is to accept any members to join this
> group,
> > > > even
> > > > > > if the
> > > > > > > > member is new or ever joined or what. As long as we have the
> > > > > > generationId
> > > > > > > > in the subscription metadata, the consumer lead can leverage
> the
> > > > info
> > > > > > to
> > > > > > > > ignore the old ownedPartitions (or do other handling), and
> the
> > > > > > rebalance
> > > > > > > > can still complete successfully and correctly. On the other
> hand,
> > > > if
> > > > > > we did
> > > > > > > > the generation check on JoinGroupRequest, and return
> > > > > > `ILLEGAL_GENERATION`
> > > > > > > > back to consumer, the consumer needs to clear its generation
> info
> > > > and
> > > > > > > > rejoin the group to continue the rebalance. It needs more
> > > > > > request/response
> > > > > > > > network and slow down the rebalance.
> > > > > > > >
> > > > > > > > So I think we should add the `generationId` field into
> > > Subscription
> > > > > > > > protocol to achieve what we want.
> > > > > > > >
> > > > > > > > Thank you.
> > > > > > > > Luke
> > > > > > > >
> > > > > > > > On Thu, Nov 18, 2021 at 8:51 PM Luke Chen <show...@gmail.com
> >
> > > > wrote:
> > > > > > > >
> > > > > > > >> Hi David,
> > > > > > > >> Thanks for your feedback.
> > > > > > > >>
> > > > > > > >> I've updated the KIP for your comments (1)(2).
> > > > > > > >> For (3), it's a good point! Yes, we didn't deserialize the
> > > > > > subscription
> > > > > > > >> metadata on broker side, and it's not necessary to add
> overhead
> > > on
> > > > > > broker
> > > > > > > >> side. And, yes, I think we can fix the original issue by
> adding
> > > a
> > > > > > > >> "generation" field into `JoinGroupRequest` instead, and also
> > > add a
> > > > > > field
> > > > > > > >> into `JoinGroupResponse` in `JoinGroupResponseMember` field.
> > > That
> > > > > > way, the
> > > > > > > >> broker can identify the old member from `JoinGroupRequest`.
> And
> > > > the
> > > > > > > >> assignor can also get the "generation" info via the
> > > `Subscription`
> > > > > > instance.
> > > > > > > >>
> > > > > > > >> I'll update the KIP to add "generation" field into
> > > > > `JoinGroupRequest`
> > > > > > and
> > > > > > > >> `JoinGroupResponse`, if there is no other options.
> > > > > > > >>
> > > > > > > >> Thank you.
> > > > > > > >> Luke
> > > > > > > >>
> > > > > > > >>
> > > > > > > >> On Tue, Nov 16, 2021 at 12:31 AM David Jacot
> > > > > > <dja...@confluent.io.invalid>
> > > > > > > >> wrote:
> > > > > > > >>
> > > > > > > >>> Hi Luke,
> > > > > > > >>>
> > > > > > > >>> Thanks for the KIP. Overall, I think that the motivation
> makes
> > > > > > sense. I
> > > > > > > >>> have a couple of comments/questions:
> > > > > > > >>>
> > > > > > > >>> 1. In the Public Interfaces section, it would be great if
> you
> > > > could
> > > > > > put
> > > > > > > >>> the
> > > > > > > >>> end state not the current one.
> > > > > > > >>>
> > > > > > > >>> 2. Do we need to update the Subscription class to expose
> the
> > > > > > > >>> generation? If so, it would be great to mention it in the
> > > Public
> > > > > > > >>> Interfaces section as well.
> > > > > > > >>>
> > > > > > > >>> 3. You mention that the broker will set the generation if
> the
> > > > > > > >>> subscription
> > > > > > > >>> contains a sentinel value (-1). As of today, the broker
> does
> > > not
> > > > > > parse
> > > > > > > >>> the subscription so I am not sure how/why we would do
> this. I
> > > > > suppose
> > > > > > > >>> that we could add a `generation` field to the
> JoinGroupRequest
> > > > > > instead
> > > > > > > >>> to do the fencing that you describe while handling the
> sentinel
> > > > in
> > > > > > the
> > > > > > > >>> assignor directly. If we would add the `generation` to the
> > > > request
> > > > > > > >>> itself,
> > > > > > > >>> would we need the `generation` in the subscription
> protocol as
> > > > > well?
> > > > > > > >>>
> > > > > > > >>> Best,
> > > > > > > >>> David
> > > > > > > >>>
> > > > > > > >>> On Fri, Nov 12, 2021 at 3:31 AM Luke Chen <
> show...@gmail.com>
> > > > > wrote:
> > > > > > > >>> >
> > > > > > > >>> > Hi all,
> > > > > > > >>> >
> > > > > > > >>> > I'd like to start the discussion for KIP-792: Add
> > > "generation"
> > > > > > field
> > > > > > > >>> into
> > > > > > > >>> > consumer protocol.
> > > > > > > >>> >
> > > > > > > >>> > The goal of this KIP is to allow assignor/consumer
> > > > > > coordinator/group
> > > > > > > >>> > coordinator to have a way to identify the out-of-date
> > > > > > > >>> members/assignments.
> > > > > > > >>> >
> > > > > > > >>> > Detailed description can be found here:
> > > > > > > >>> >
> > > > > > > >>>
> > > > > >
> > > > >
> > > >
> > >
> https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=191336614
> > > > > > > >>> >
> > > > > > > >>> > Any feedback is welcome.
> > > > > > > >>> >
> > > > > > > >>> > Thank you.
> > > > > > > >>> > Luke
> > > > > > > >>>
> > > > > > > >>
> > > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > -- Guozhang
> > > >
> > >
> >
> >
> > --
> > -- Guozhang
>
