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From Rajini Sivaram <rajinisiva...@gmail.com>
Subject Re: [DISCUSS] KIP-289: Improve the default group id behavior in KafkaConsumer
Date Fri, 20 Jul 2018 17:22:16 GMT
+1 to deprecate use of "" as group.id since it is odd to have a resource
name that you cannot set ACLs for. Agree, we have to support older clients
though.

Thanks,

Rajini

On Fri, Jul 20, 2018 at 5:25 PM, Jason Gustafson <jason@confluent.io> wrote:

> Hi Vahid,
>
> Sorry for getting to this so late. I think there are two things here:
>
> 1. The use of "" as a groupId has always been a dubious practice at best.
> We definitely ought to deprecate its use in the client. Perhaps in the next
> major release, we can remove support completely. However, since older
> clients depend on it, we may have to continue letting the broker support it
> to some extent. Perhaps we just need to bump the OffsetCommit request API
> and only accept the offset commit for older versions. You probably have to
> do this anyway if you want to introduce the new error code since old
> clients will not expect it.
>
> 2. There should be a way for the consumer to indicate that it has no group
> id and will not commit offsets. This is an explicit instruction that the
> consumer should not bother with coordinator lookup and such. We currently
> have some brittle logic in place to let users avoid the coordinator lookup,
> but it is a bit error-prone. I was hoping that we could change the default
> value of group.id to be null so that the user had to take an explicit
> action to opt into coordinator management (groups or offsets). However, it
> is true that some users may be unknowingly depending on offset storage if
> they are using both the default group.id and the default
> enable.auto.commit. Perhaps one option is to disable enable.auto.commit
> automatically if no group.id is specified? I am not sure if there are any
> drawbacks, but my feeling is that implicit use of the empty group.id to
> commit offsets is more likely to be causing users unexpected problems than
> actually providing a useful capability.
>
> Thoughts?
>
> Thanks,
> Jason
>
>
>
>
> On Mon, May 28, 2018 at 9:50 AM, Vahid S Hashemian <
> vahidhashemian@us.ibm.com> wrote:
>
> > Hi Viktor,
> >
> > Thanks for sharing your opinion.
> > So you're in favor of disallowing the empty ("") group id altogether
> (even
> > for fetching).
> > Given that ideally no one should be using the empty group id (at least in
> > a production setting) I think the impact would be minimal in either case.
> >
> > But as you said, let's hear what others think and I'd be happy to modify
> > the KIP if needed.
> >
> > Regards.
> > --Vahid
> >
> >
> >
> >
> > From:   Viktor Somogyi <viktorsomogyi@gmail.com>
> > To:     dev <dev@kafka.apache.org>
> > Date:   05/28/2018 05:18 AM
> > Subject:        Re: [DISCUSS] KIP-289: Improve the default group id
> > behavior in KafkaConsumer
> >
> >
> >
> > Hi Vahid,
> >
> > (with the argument that using the default group id for offset commit
> > should not be the user's intention in practice).
> >
> > Yea, so in my opinion too this use case doesn't seem too practical. Also
> I
> > think breaking the offset commit is not smaller from this perspective
> than
> > breaking fetch and offset fetch. If we suppose that someone uses the
> > default group id and we break the offset commit then that might be harder
> > to detect than breaking the whole thing altogether. (If we think about an
> > upgrade situation.)
> > So since we think it is not a practical use case, I think it would be
> > better to break altogether but ofc that's just my 2 cents :). Let's
> gather
> > other's input as well.
> >
> > Cheers,
> > Viktor
> >
> > On Fri, May 25, 2018 at 5:43 PM, Vahid S Hashemian <
> > vahidhashemian@us.ibm.com> wrote:
> >
> > > Hi Victor,
> > >
> > > Thanks for reviewing the KIP.
> > >
> > > Yes, to minimize the backward compatibility impact, there would be no
> > harm
> > > in letting a stand-alone consumer consume messages under a "" group id
> > (as
> > > long as there is no offset commit).
> > > It would have to knowingly seek to an offset or rely on the
> > > auto.offset.reset config for the starting offset.
> > > This way the existing functionality would be preserved for the most
> part
> > > (with the argument that using the default group id for offset commit
> > > should not be the user's intention in practice).
> > >
> > > Does it seem reasonable?
> > >
> > > Thanks.
> > > --Vahid
> > >
> > >
> > >
> > >
> > > From:   Viktor Somogyi <viktorsomogyi@gmail.com>
> > > To:     dev <dev@kafka.apache.org>
> > > Date:   05/25/2018 04:56 AM
> > > Subject:        Re: [DISCUSS] KIP-289: Improve the default group id
> > > behavior in KafkaConsumer
> > >
> > >
> > >
> > > Hi Vahid,
> > >
> > > When reading your KIP I coldn't fully understand why did you decide at
> > > failing with "offset_commit" in case #2? Can't we fail with an empty
> > group
> > > id even in "fetch" or "fetch_offset"? What was the reason for deciding
> > to
> > > fail at "offset_commit"? Was it because of upgrade compatibility
> > reasons?
> > >
> > > Thanks,
> > > Viktor
> > >
> > > On Thu, May 24, 2018 at 12:06 AM, Ted Yu <yuzhihong@gmail.com> wrote:
> > >
> > > > Looks good to me.
> > > > -------- Original message --------From: Vahid S Hashemian <
> > > > vahidhashemian@us.ibm.com> Date: 5/23/18  11:19 AM  (GMT-08:00) To:
> > > > dev@kafka.apache.org Subject: Re: [DISCUSS] KIP-289: Improve the
> > default
> > > > group id behavior in KafkaConsumer
> > > > Hi Ted,
> > > >
> > > > Thanks for reviewing the KIP. I updated the KIP and introduced an
> > error
> > > > code for the scenario described.
> > > >
> > > > --Vahid
> > > >
> > > >
> > > >
> > > >
> > > > From:   Ted Yu <yuzhihong@gmail.com>
> > > > To:     dev@kafka.apache.org
> > > > Date:   04/27/2018 04:31 PM
> > > > Subject:        Re: [DISCUSS] KIP-289: Improve the default group id
> > > > behavior in KafkaConsumer
> > > >
> > > >
> > > >
> > > > bq. If they attempt an offset commit they will receive an error.
> > > >
> > > > Can you outline what specific error would be encountered ?
> > > >
> > > > Thanks
> > > >
> > > > On Fri, Apr 27, 2018 at 2:17 PM, Vahid S Hashemian <
> > > > vahidhashemian@us.ibm.com> wrote:
> > > >
> > > > > Hi all,
> > > > >
> > > > > I have drafted a proposal for improving the behavior of
> > KafkaConsumer
> > > > when
> > > > > using the default group id:
> > > > >
> > > >
> > >
> > https://cwiki.apache.org/confluence/display/KAFKA/KIP-
> >
> > >
> > > >
> > > > > 289%3A+Improve+the+default+group+id+behavior+in+KafkaConsumer
> > > > > The proposal based on the issue and suggestion reported in
> > KAFKA-6774.
> > > > >
> > > > > Your feedback is welcome!
> > > > >
> > > > > Thanks.
> > > > > --Vahid
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> >
> >
>

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