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From Dong Lin <lindon...@gmail.com>
Subject Re: [DISCUSS] KIP-354 Time-based log compaction policy
Date Wed, 07 Nov 2018 02:49:59 GMT
Hey Xiongqi,

Thanks for the update. A few more comments below

1) According to the definition of
kafka.log:type=LogCleaner,name=max-compaction-delay, it seems that the
metric value will be a large negative number if max.compaction.lag.ms is
MAX_LONG. Would this be a problem? Also, it seems weird that the value of
the metric is defined w.r.t. how often the log cleaner is run.

2) Not sure if we need the metric num-logs-compacted-by-max-compaction-lag
in addition to max-compaction-delay. It seems that operator can just use
max-compaction-delay to determine whether the max.compaction.lag is
properly enforced in a quantitative manner. Also, the metric name
`num-logs-compacted-by-max-compaction-lag` is inconsistent with its
intended meaning, i.e. the number of logs that needs to be compacted due to
max.compaction.lag but not yet compacted. So it is probably simple to just
remove this metric.

3) The KIP currently says that "a message record has a guaranteed
upper-bound in time to become mandatory for compaction". The word
"guarantee" may be misleading because the message may still not be
compacted within max.compaction.lag after its creation. Could you clarify
the exact semantics of the max.compaction.lag.ms in the Public Interface
section?

4) The KIP's proposed change will estimate earliest message timestamp for
un-compacted log segments. Can you explain how broker determines whether a
segment has been compacted after the broker is restarted?

5) 2.b in Proposed Change section provides two way to get timestamp. To
make the KIP easier to read for future reference, could we just mention the
method that we plan to use and move the other solution to the rejected
alternative section?

6) Based on the discussion (i.e. point 2 in the previous email), it is said
that we can assume all messages have timestamp and the feature added in
this KIP can be skipped for those messages which do not have timestamp. So
do we still need to use "segment.largestTimestamp - maxSegmentMs" in
Proposed Change section 2.a?

7) Based on the discussion (i.e. point 8 in the previous email), if this
KIP requires user to monitor certain existing metrics for performance
impact added in this KIP, can we list the metrics in the KIP for user's
convenience?


Thanks,
Dong

On Mon, Oct 29, 2018 at 3:16 PM xiongqi wu <xiongqiwu@gmail.com> wrote:

> Hi Dong,
> I have updated the KIP to address your comments.
> One correction to previous Email:
> after offline discussion with Dong,  we decide to use MAX_LONG as default
> value for max.compaction.lag.ms.
>
>
> Xiongqi (Wesley) Wu
>
>
> On Mon, Oct 29, 2018 at 12:15 PM xiongqi wu <xiongqiwu@gmail.com> wrote:
>
> > Hi Dong,
> >
> > Thank you for your comment.  See my inline comments.
> > I will update the KIP shortly.
> >
> > Xiongqi (Wesley) Wu
> >
> >
> > On Sun, Oct 28, 2018 at 9:17 PM Dong Lin <lindong28@gmail.com> wrote:
> >
> >> Hey Xiongqi,
> >>
> >> Sorry for late reply. I have some comments below:
> >>
> >> 1) As discussed earlier in the email list, if the topic is configured
> with
> >> both deletion and compaction, in some cases messages produced a long
> time
> >> ago can not be deleted based on time. This is a valid use-case because
> we
> >> actually have topic which is configured with both deletion and
> compaction
> >> policy. And we should enforce the semantics for both policy. Solution A
> >> sounds good. We do not need interface change (e.g. extra config) to
> >> enforce
> >> solution A. All we need is to update implementation so that when broker
> >> compacts a topic, if the message has timestamp (which is the common
> case),
> >> messages that are too old (based on the time-based retention config)
> will
> >> be discarded. Since this is a valid issue and it is also related to the
> >> guarantee of when a message can be deleted, can we include the solution
> of
> >> this problem in the KIP?
> >>
> > ======  This makes sense.  We can use similar approach to increase the
> log
> > start offset.
> >
> >>
> >> 2) It is probably OK to assume that all messages have timestamp. The
> >> per-message timestamp was introduced into Kafka 0.10.0 with KIP-31 and
> >> KIP-32 as of Feb 2016. Kafka 0.10.0 or earlier versions are no longer
> >> supported. Also, since the use-case for this feature is primarily for
> >> GDPR,
> >> we can assume that client library has already been upgraded to support
> >> SSL,
> >> which feature is added after KIP-31 and KIP-32.
> >>
> >>  =========>  Ok. We can use message timestamp to delete expired records
> > if both compaction and retention are enabled.
> >
> >
> > 3) In Proposed Change section 2.a, it is said that
> segment.largestTimestamp
> >> - maxSegmentMs can be used to determine the timestamp of the earliest
> >> message. Would it be simpler to just use the create time of the file to
> >> determine the time?
> >>
> >> ========>  Linux/Java doesn't provide API for file creation time because
> > some filesystem type doesn't provide file creation time.
> >
> >
> >> 4) The KIP suggests to use must-clean-ratio to select the partition to
> be
> >> compacted. Unlike dirty ratio which is mostly for performance, the logs
> >> whose "must-clean-ratio" is non-zero must be compacted immediately for
> >> correctness reason (and for GDPR). And if this can no be achieved
> because
> >> e.g. broker compaction throughput is too low, investigation will be
> >> needed.
> >> So it seems simpler to first compact logs which has segment whose
> earliest
> >> timetamp is earlier than now - max.compaction.lag.ms, instead of
> defining
> >> must-clean-ratio and sorting logs based on this value.
> >>
> >>
> > ======>  Good suggestion. This can simply the implementation quite a bit
> > if we are not too concerned about compaction of GDPR required partition
> > queued behind some large partition.  The actual compaction completion
> time
> > is not guaranteed anyway.
> >
> >
> >> 5) The KIP says max.compaction.lag.ms is 0 by default and it is also
> >> suggested that 0 means disable. Should we set this value to MAX_LONG by
> >> default to effectively disable the feature added in this KIP?
> >>
> >> ====> I would rather use 0 so the corresponding code path will not be
> > exercised.  By using MAX_LONG, we would theoretically go through related
> > code to find out whether the partition is required to be compacted to
> > satisfy MAX_LONG.
> >
> > 6) It is probably cleaner and readable not to include in Public Interface
> >> section those configs whose meaning is not changed.
> >>
> >> ====> I will clean that up.
> >
> > 7) The goal of this KIP is to ensure that log segment whose earliest
> >> message is earlier than a given threshold will be compacted. This goal
> may
> >> not be achieved if the compact throughput can not catchup with the total
> >> bytes-in-rate for the compacted topics on the broker. Thus we need an
> easy
> >> way to tell operator whether this goal is achieved. If we don't already
> >> have such metric, maybe we can include metrics to show 1) the total
> number
> >> of log segments (or logs) which needs to be immediately compacted as
> >> determined by max.compaction.lag; and 2) the maximum value of now -
> >> earliest_time_stamp_of_segment among all segments that needs to be
> >> compacted.
> >>
> >> =======> good suggestion.  I will update KIP for these metrics.
> >
> > 8) The Performance Impact suggests user to use the existing metrics to
> >> monitor the performance impact of this KIP. It i useful to list mean of
> >> each jmx metrics that we want user to monitor, and possibly explain how
> to
> >> interpret the value of these metrics to determine whether there is
> >> performance issue.
> >>
> >> =========>  I will update the KIP.
> >
> >> Thanks,
> >> Dong
> >>
> >> On Tue, Oct 16, 2018 at 10:53 AM xiongqi wu <xiongqiwu@gmail.com>
> wrote:
> >>
> >> > Mayuresh,
> >> >
> >> > Thanks for the comments.
> >> > The requirement is that we need to pick up segments that are older
> than
> >> > maxCompactionLagMs for compaction.
> >> > maxCompactionLagMs is an upper-bound, which implies that picking up
> >> > segments for compaction earlier doesn't violated the policy.
> >> > We use the creation time of a segment as an estimation of its records
> >> > arrival time, so these records can be compacted no later than
> >> > maxCompactionLagMs.
> >> >
> >> > On the other hand, compaction is an expensive operation, we don't want
> >> to
> >> > compact the log partition whenever a new segment is sealed.
> >> > Therefore, we want to pick up a segment for compaction when the
> segment
> >> is
> >> > closed to mandatory max compaction lag (so we use segment creation
> time
> >> as
> >> > an estimation.)
> >> >
> >> >
> >> > Xiongqi (Wesley) Wu
> >> >
> >> >
> >> > On Mon, Oct 15, 2018 at 5:54 PM Mayuresh Gharat <
> >> > gharatmayuresh15@gmail.com>
> >> > wrote:
> >> >
> >> > > Hi Wesley,
> >> > >
> >> > > Thanks for the KIP and sorry for being late to the party.
> >> > >  I wanted to understand, the scenario you mentioned in Proposed
> >> changes :
> >> > >
> >> > > -
> >> > > >
> >> > > > Estimate the earliest message timestamp of an un-compacted log
> >> segment.
> >> > > we
> >> > > > only need to estimate earliest message timestamp for un-compacted
> >> log
> >> > > > segments to ensure timely compaction because the deletion requests
> >> that
> >> > > > belong to compacted segments have already been processed.
> >> > > >
> >> > > >    1.
> >> > > >
> >> > > >    for the first (earliest) log segment:  The estimated earliest
> >> > > >    timestamp is set to the timestamp of the first message if
> >> timestamp
> >> > is
> >> > > >    present in the message. Otherwise, the estimated earliest
> >> timestamp
> >> > > is set
> >> > > >    to "segment.largestTimestamp - maxSegmentMs”
> >> > > >     (segment.largestTimestamp is lastModified time of the log
> >> segment
> >> > or
> >> > > max
> >> > > >    timestamp we see for the log segment.). In the later case, the
> >> > actual
> >> > > >    timestamp of the first message might be later than the
> >> estimation,
> >> > > but it
> >> > > >    is safe to pick up the log for compaction earlier.
> >> > > >
> >> > > > When we say "actual timestamp of the first message might be later
> >> than
> >> > > the
> >> > > estimation, but it is safe to pick up the log for compaction
> >> earlier.",
> >> > > doesn't that violate the assumption that we will consider a segment
> >> for
> >> > > compaction only if the time of creation the segment has crossed the
> >> "now
> >> > -
> >> > > maxCompactionLagMs" ?
> >> > >
> >> > > Thanks,
> >> > >
> >> > > Mayuresh
> >> > >
> >> > > On Mon, Sep 3, 2018 at 7:28 PM Brett Rann <brann@zendesk.com.invalid
> >
> >> > > wrote:
> >> > >
> >> > > > Might also be worth moving to a vote thread? Discussion seems to
> >> have
> >> > > gone
> >> > > > as far as it can.
> >> > > >
> >> > > > > On 4 Sep 2018, at 12:08, xiongqi wu <xiongqiwu@gmail.com>
> wrote:
> >> > > > >
> >> > > > > Brett,
> >> > > > >
> >> > > > > Yes, I will post PR tomorrow.
> >> > > > >
> >> > > > > Xiongqi (Wesley) Wu
> >> > > > >
> >> > > > >
> >> > > > > On Sun, Sep 2, 2018 at 6:28 PM Brett Rann
> >> <brann@zendesk.com.invalid
> >> > >
> >> > > > wrote:
> >> > > > >
> >> > > > > > +1 (non-binding) from me on the interface. I'd like to see
> >> someone
> >> > > > familiar
> >> > > > > > with
> >> > > > > > the code comment on the approach, and note there's a couple of
> >> > > > different
> >> > > > > > approaches: what's documented in the KIP, and what Xiaohe Dong
> >> was
> >> > > > working
> >> > > > > > on
> >> > > > > > here:
> >> > > > > >
> >> > > > > >
> >> > > >
> >> > >
> >> >
> >>
> https://github.com/dongxiaohe/kafka/tree/dongxiaohe/log-cleaner-compaction-max-lifetime-2.0
> >> > > > > >
> >> > > > > > If you have code working already Xiongqi Wu could you share a
> >> PR?
> >> > I'd
> >> > > > be
> >> > > > > > happy
> >> > > > > > to start testing.
> >> > > > > >
> >> > > > > > On Tue, Aug 28, 2018 at 5:57 AM xiongqi wu <
> xiongqiwu@gmail.com
> >> >
> >> > > > wrote:
> >> > > > > >
> >> > > > > > > Hi All,
> >> > > > > > >
> >> > > > > > > Do you have any additional comments on this KIP?
> >> > > > > > >
> >> > > > > > >
> >> > > > > > > On Thu, Aug 16, 2018 at 9:17 PM, xiongqi wu <
> >> xiongqiwu@gmail.com
> >> > >
> >> > > > wrote:
> >> > > > > > >
> >> > > > > > > > on 2)
> >> > > > > > > > The offsetmap is built starting from dirty segment.
> >> > > > > > > > The compaction starts from the beginning of the log
> >> partition.
> >> > > > That's
> >> > > > > > how
> >> > > > > > > > it ensure the deletion of tomb keys.
> >> > > > > > > > I will double check tomorrow.
> >> > > > > > > >
> >> > > > > > > > Xiongqi (Wesley) Wu
> >> > > > > > > >
> >> > > > > > > >
> >> > > > > > > > On Thu, Aug 16, 2018 at 6:46 PM Brett Rann
> >> > > > <brann@zendesk.com.invalid>
> >> > > > > > > > wrote:
> >> > > > > > > >
> >> > > > > > > >> To just clarify a bit on 1. whether there's an external
> >> > > storage/DB
> >> > > > > > isn't
> >> > > > > > > >> relevant here.
> >> > > > > > > >> Compacted topics allow a tombstone record to be sent (a
> >> null
> >> > > value
> >> > > > > > for a
> >> > > > > > > >> key) which
> >> > > > > > > >> currently will result in old values for that key being
> >> deleted
> >> > > if
> >> > > > some
> >> > > > > > > >> conditions are met.
> >> > > > > > > >> There are existing controls to make sure the old values
> >> will
> >> > > stay
> >> > > > > > around
> >> > > > > > > >> for a minimum
> >> > > > > > > >> time at least, but no dedicated control to ensure the
> >> > tombstone
> >> > > > will
> >> > > > > > > >> delete
> >> > > > > > > >> within a
> >> > > > > > > >> maximum time.
> >> > > > > > > >>
> >> > > > > > > >> One popular reason that maximum time for deletion is
> >> desirable
> >> > > > right
> >> > > > > > now
> >> > > > > > > >> is
> >> > > > > > > >> GDPR with
> >> > > > > > > >> PII. But we're not proposing any GDPR awareness in kafka,
> >> just
> >> > > > being
> >> > > > > > > able
> >> > > > > > > >> to guarantee
> >> > > > > > > >> a max time where a tombstoned key will be removed from
> the
> >> > > > compacted
> >> > > > > > > >> topic.
> >> > > > > > > >>
> >> > > > > > > >> on 2)
> >> > > > > > > >> huh, i thought it kept track of the first dirty segment
> and
> >> > > didn't
> >> > > > > > > >> recompact older "clean" ones.
> >> > > > > > > >> But I didn't look at code or test for that.
> >> > > > > > > >>
> >> > > > > > > >> On Fri, Aug 17, 2018 at 10:57 AM xiongqi wu <
> >> > > xiongqiwu@gmail.com>
> >> > > > > > > wrote:
> >> > > > > > > >>
> >> > > > > > > >> > 1, Owner of data (in this sense, kafka is the not the
> >> owner
> >> > of
> >> > > > data)
> >> > > > > > > >> > should keep track of lifecycle of the data in some
> >> external
> >> > > > > > > storage/DB.
> >> > > > > > > >> > The owner determines when to delete the data and send
> the
> >> > > delete
> >> > > > > > > >> request to
> >> > > > > > > >> > kafka. Kafka doesn't know about the content of data but
> >> to
> >> > > > provide a
> >> > > > > > > >> mean
> >> > > > > > > >> > for deletion.
> >> > > > > > > >> >
> >> > > > > > > >> > 2 , each time compaction runs, it will start from first
> >> > > > segments (no
> >> > > > > > > >> > matter if it is compacted or not). The time estimation
> >> here
> >> > is
> >> > > > only
> >> > > > > > > used
> >> > > > > > > >> > to determine whether we should run compaction on this
> log
> >> > > > partition.
> >> > > > > > > So
> >> > > > > > > >> we
> >> > > > > > > >> > only need to estimate uncompacted segments.
> >> > > > > > > >> >
> >> > > > > > > >> > On Thu, Aug 16, 2018 at 5:35 PM, Dong Lin <
> >> > > lindong28@gmail.com>
> >> > > > > > > wrote:
> >> > > > > > > >> >
> >> > > > > > > >> > > Hey Xiongqi,
> >> > > > > > > >> > >
> >> > > > > > > >> > > Thanks for the update. I have two questions for the
> >> latest
> >> > > > KIP.
> >> > > > > > > >> > >
> >> > > > > > > >> > > 1) The motivation section says that one use case is
> to
> >> > > delete
> >> > > > PII
> >> > > > > > > >> > (Personal
> >> > > > > > > >> > > Identifiable information) data within 7 days while
> >> keeping
> >> > > > non-PII
> >> > > > > > > >> > > indefinitely in compacted format. I suppose the
> >> use-case
> >> > > > depends
> >> > > > > > on
> >> > > > > > > >> the
> >> > > > > > > >> > > application to determine when to delete those PII
> data.
> >> > > Could
> >> > > > you
> >> > > > > > > >> explain
> >> > > > > > > >> > > how can application reliably determine the set of
> keys
> >> > that
> >> > > > should
> >> > > > > > > be
> >> > > > > > > >> > > deleted? Is application required to always messages
> >> from
> >> > the
> >> > > > topic
> >> > > > > > > >> after
> >> > > > > > > >> > > every restart and determine the keys to be deleted by
> >> > > looking
> >> > > > at
> >> > > > > > > >> message
> >> > > > > > > >> > > timestamp, or is application supposed to persist the
> >> key->
> >> > > > > > timstamp
> >> > > > > > > >> > > information in a separate persistent storage system?
> >> > > > > > > >> > >
> >> > > > > > > >> > > 2) It is mentioned in the KIP that "we only need to
> >> > estimate
> >> > > > > > > earliest
> >> > > > > > > >> > > message timestamp for un-compacted log segments
> because
> >> > the
> >> > > > > > deletion
> >> > > > > > > >> > > requests that belong to compacted segments have
> already
> >> > been
> >> > > > > > > >> processed".
> >> > > > > > > >> > > Not sure if it is correct. If a segment is compacted
> >> > before
> >> > > > user
> >> > > > > > > sends
> >> > > > > > > >> > > message to delete a key in this segment, it seems
> that
> >> we
> >> > > > still
> >> > > > > > need
> >> > > > > > > >> to
> >> > > > > > > >> > > ensure that the segment will be compacted again
> within
> >> the
> >> > > > given
> >> > > > > > > time
> >> > > > > > > >> > after
> >> > > > > > > >> > > the deletion is requested, right?
> >> > > > > > > >> > >
> >> > > > > > > >> > > Thanks,
> >> > > > > > > >> > > Dong
> >> > > > > > > >> > >
> >> > > > > > > >> > > On Thu, Aug 16, 2018 at 10:27 AM, xiongqi wu <
> >> > > > xiongqiwu@gmail.com
> >> > > > > > >
> >> > > > > > > >> > wrote:
> >> > > > > > > >> > >
> >> > > > > > > >> > > > Hi Xiaohe,
> >> > > > > > > >> > > >
> >> > > > > > > >> > > > Quick note:
> >> > > > > > > >> > > > 1) Use minimum of segment.ms and
> >> max.compaction.lag.ms
> >> > > > > > > >> > > > <http://max.compaction.ms
> >> > > > > > > <http://max.compaction.ms>
> >> > > > > > > >> > <http://max.compaction.ms
> >> > > > > > > <http://max.compaction.ms>>>
> >> > > > > > > >> > > >
> >> > > > > > > >> > > > 2) I am not sure if I get your second question.
> >> first,
> >> > we
> >> > > > have
> >> > > > > > > >> jitter
> >> > > > > > > >> > > when
> >> > > > > > > >> > > > we roll the active segment. second, on each
> >> compaction,
> >> > we
> >> > > > > > compact
> >> > > > > > > >> upto
> >> > > > > > > >> > > > the offsetmap could allow. Those will not lead to
> >> > perfect
> >> > > > > > > compaction
> >> > > > > > > >> > > storm
> >> > > > > > > >> > > > overtime. In addition, I expect we are setting
> >> > > > > > > >> max.compaction.lag.ms
> >> > > > > > > >> > on
> >> > > > > > > >> > > > the order of days.
> >> > > > > > > >> > > >
> >> > > > > > > >> > > > 3) I don't have access to the confluent community
> >> slack
> >> > > for
> >> > > > > > now. I
> >> > > > > > > >> am
> >> > > > > > > >> > > > reachable via the google handle out.
> >> > > > > > > >> > > > To avoid the double effort, here is my plan:
> >> > > > > > > >> > > > a) Collect more feedback and feature requriement on
> >> the
> >> > > KIP.
> >> > > > > > > >> > > > b) Wait unitl this KIP is approved.
> >> > > > > > > >> > > > c) I will address any additional requirements in
> the
> >> > > > > > > implementation.
> >> > > > > > > >> > (My
> >> > > > > > > >> > > > current implementation only complies to whatever
> >> > described
> >> > > > in
> >> > > > > > the
> >> > > > > > > >> KIP
> >> > > > > > > >> > > now)
> >> > > > > > > >> > > > d) I can share the code with the you and community
> >> see
> >> > you
> >> > > > want
> >> > > > > > to
> >> > > > > > > >> add
> >> > > > > > > >> > > > anything.
> >> > > > > > > >> > > > e) submission through committee
> >> > > > > > > >> > > >
> >> > > > > > > >> > > >
> >> > > > > > > >> > > > On Wed, Aug 15, 2018 at 11:42 PM, XIAOHE DONG <
> >> > > > > > > >> dannyrivclo@gmail.com>
> >> > > > > > > >> > > > wrote:
> >> > > > > > > >> > > >
> >> > > > > > > >> > > > > Hi Xiongqi
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > Thanks for thinking about implementing this as
> >> well.
> >> > :)
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > I was thinking about using `segment.ms` to
> trigger
> >> > the
> >> > > > > > segment
> >> > > > > > > >> roll.
> >> > > > > > > >> > > > > Also, its value can be the largest time bias for
> >> the
> >> > > > record
> >> > > > > > > >> deletion.
> >> > > > > > > >> > > For
> >> > > > > > > >> > > > > example, if the `segment.ms` is 1 day and `
> >> > > > max.compaction.ms`
> >> > > > > > > is
> >> > > > > > > >> 30
> >> > > > > > > >> > > > days,
> >> > > > > > > >> > > > > the compaction may happen around 31 days.
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > For my curiosity, is there a way we can do some
> >> > > > performance
> >> > > > > > test
> >> > > > > > > >> for
> >> > > > > > > >> > > this
> >> > > > > > > >> > > > > and any tools you can recommend. As you know,
> >> > > previously,
> >> > > > it
> >> > > > > > is
> >> > > > > > > >> > cleaned
> >> > > > > > > >> > > > up
> >> > > > > > > >> > > > > by respecting dirty ratio, but now it may happen
> >> > anytime
> >> > > > if
> >> > > > > > max
> >> > > > > > > >> lag
> >> > > > > > > >> > has
> >> > > > > > > >> > > > > passed for each message. I wonder what would
> >> happen if
> >> > > > clients
> >> > > > > > > >> send
> >> > > > > > > >> > > huge
> >> > > > > > > >> > > > > amount of tombstone records at the same time.
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > I am looking forward to have a quick chat with
> you
> >> to
> >> > > > avoid
> >> > > > > > > double
> >> > > > > > > >> > > effort
> >> > > > > > > >> > > > > on this. I am in confluent community slack during
> >> the
> >> > > work
> >> > > > > > time.
> >> > > > > > > >> My
> >> > > > > > > >> > > name
> >> > > > > > > >> > > > is
> >> > > > > > > >> > > > > Xiaohe Dong. :)
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > Rgds
> >> > > > > > > >> > > > > Xiaohe Dong
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > On 2018/08/16 01:22:22, xiongqi wu <
> >> > xiongqiwu@gmail.com
> >> > > >
> >> > > > > > wrote:
> >> > > > > > > >> > > > > > Brett,
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > Thank you for your comments.
> >> > > > > > > >> > > > > > I was thinking since we already has immediate
> >> > > compaction
> >> > > > > > > >> setting by
> >> > > > > > > >> > > > > setting
> >> > > > > > > >> > > > > > min dirty ratio to 0, so I decide to use "0" as
> >> > > disabled
> >> > > > > > > state.
> >> > > > > > > >> > > > > > I am ok to go with -1(disable), 0 (immediate)
> >> > options.
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > For the implementation, there are a few
> >> differences
> >> > > > between
> >> > > > > > > mine
> >> > > > > > > >> > and
> >> > > > > > > >> > > > > > "Xiaohe Dong"'s :
> >> > > > > > > >> > > > > > 1) I used the estimated creation time of a log
> >> > segment
> >> > > > > > instead
> >> > > > > > > >> of
> >> > > > > > > >> > > > largest
> >> > > > > > > >> > > > > > timestamp of a log to determine the compaction
> >> > > > eligibility,
> >> > > > > > > >> > because a
> >> > > > > > > >> > > > log
> >> > > > > > > >> > > > > > segment might stay as an active segment up to
> >> "max
> >> > > > > > compaction
> >> > > > > > > >> lag".
> >> > > > > > > >> > > > (see
> >> > > > > > > >> > > > > > the KIP for detail).
> >> > > > > > > >> > > > > > 2) I measure how much bytes that we must clean
> to
> >> > > > follow the
> >> > > > > > > >> "max
> >> > > > > > > >> > > > > > compaction lag" rule, and use that to determine
> >> the
> >> > > > order of
> >> > > > > > > >> > > > compaction.
> >> > > > > > > >> > > > > > 3) force active segment to roll to follow the
> >> "max
> >> > > > > > compaction
> >> > > > > > > >> lag"
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > I can share my code so we can coordinate.
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > I haven't think about a new API to force a
> >> > compaction.
> >> > > > what
> >> > > > > > is
> >> > > > > > > >> the
> >> > > > > > > >> > > use
> >> > > > > > > >> > > > > case
> >> > > > > > > >> > > > > > for this one?
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > On Wed, Aug 15, 2018 at 5:33 PM, Brett Rann
> >> > > > > > > >> > > <brann@zendesk.com.invalid
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > > wrote:
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > > We've been looking into this too.
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > Mailing list:
> >> > > > > > > >> > > > > > > https://lists.apache.org/thread.html/
> >> > > > > > > <https://lists.apache.org/thread.html/>
> >> > > > > > > >> > <https://lists.apache.org/thread.html/
> >> > > > > > > <https://lists.apache.org/thread.html/>>
> >> > > > > > > >> > > ed7f6a6589f94e8c2a705553f364ef
> >> > > > > > > >> > > > > > > 599cb6915e4c3ba9b561e610e4@%
> >> > 3Cdev.kafka.apache.org
> >> > > %3E
> >> > > > > > > >> > > > > > > jira wish:
> >> > > > > > https://issues.apache.org/jira/browse/KAFKA-7137
> >> > > > > > > <https://issues.apache.org/jira/browse/KAFKA-7137>
> >> > > > > > > >> > <https://issues.apache.org/jira/browse/KAFKA-7137
> >> > > > > > > <https://issues.apache.org/jira/browse/KAFKA-7137>>
> >> > > > > > > >> > > > > > > confluent slack discussion:
> >> > > > > > > >> > > > > > >
> >> > > > https://confluentcommunity.slack.com/archives/C49R61XMM/
> >> > > > > > > <https://confluentcommunity.slack.com/archives/C49R61XMM/>
> >> > > > > > > >> > <
> >> https://confluentcommunity.slack.com/archives/C49R61XMM/
> >> > > > > > > <https://confluentcommunity.slack.com/archives/C49R61XMM/>>
> >> > > > > > > >> > > > > p1530760121000039
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > A person on my team has started on code so
> you
> >> > might
> >> > > > want
> >> > > > > > to
> >> > > > > > > >> > > > > coordinate:
> >> > > > > > > >> > > > > > >
> >> > > > https://github.com/dongxiaohe/kafka/tree/dongxiaohe/log-
> >> > > > > > > <https://github.com/dongxiaohe/kafka/tree/dongxiaohe/log->
> >> > > > > > > >> > <
> >> https://github.com/dongxiaohe/kafka/tree/dongxiaohe/log-
> >> > > > > > > <https://github.com/dongxiaohe/kafka/tree/dongxiaohe/log->>
> >> > > > > > > >> > > > > > > cleaner-compaction-max-lifetime-2.0
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > He's been working with Jason Gustafson and
> >> James
> >> > > Chen
> >> > > > > > around
> >> > > > > > > >> the
> >> > > > > > > >> > > > > changes.
> >> > > > > > > >> > > > > > > You can ping him on confluent slack as Xiaohe
> >> > Dong.
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > It's great to know others are thinking on it
> as
> >> > > well.
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > You've added the requirement to force a
> segment
> >> > roll
> >> > > > which
> >> > > > > > > we
> >> > > > > > > >> > > hadn't
> >> > > > > > > >> > > > > gotten
> >> > > > > > > >> > > > > > > to yet, which is great. I was content with it
> >> not
> >> > > > > > including
> >> > > > > > > >> the
> >> > > > > > > >> > > > active
> >> > > > > > > >> > > > > > > segment.
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > > Adding topic level configuration "
> >> > > > max.compaction.lag.ms
> >> > > > > > ",
> >> > > > > > > >> and
> >> > > > > > > >> > > > > > > corresponding broker configuration "
> >> > > > > > > >> > log.cleaner.max.compaction.la
> >> > > > > > > >> > > > g.ms
> >> > > > > > > >> > > > > ",
> >> > > > > > > >> > > > > > > which is set to 0 (disabled) by default.
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > Glancing at some other settings convention
> >> seems
> >> > to
> >> > > > me to
> >> > > > > > be
> >> > > > > > > >> -1
> >> > > > > > > >> > for
> >> > > > > > > >> > > > > > > disabled (or infinite, which is more
> meaningful
> >> > > > here). 0
> >> > > > > > to
> >> > > > > > > me
> >> > > > > > > >> > > > implies
> >> > > > > > > >> > > > > > > instant, a little quicker than 1.
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > We've been trying to think about a way to
> >> trigger
> >> > > > > > compaction
> >> > > > > > > >> as
> >> > > > > > > >> > > well
> >> > > > > > > >> > > > > > > through an API call, which would need to be
> >> > flagged
> >> > > > > > > somewhere
> >> > > > > > > >> (ZK
> >> > > > > > > >> > > > > admin/
> >> > > > > > > >> > > > > > > space?) but we're struggling to think how
> that
> >> > would
> >> > > > be
> >> > > > > > > >> > coordinated
> >> > > > > > > >> > > > > across
> >> > > > > > > >> > > > > > > brokers and partitions. Have you given any
> >> thought
> >> > > to
> >> > > > > > that?
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > On Thu, Aug 16, 2018 at 8:44 AM xiongqi wu <
> >> > > > > > > >> xiongqiwu@gmail.com>
> >> > > > > > > >> > > > > wrote:
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > > Eno, Dong,
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > > I have updated the KIP. We decide not to
> >> address
> >> > > the
> >> > > > > > issue
> >> > > > > > > >> that
> >> > > > > > > >> > > we
> >> > > > > > > >> > > > > might
> >> > > > > > > >> > > > > > > > have for both compaction and time retention
> >> > > enabled
> >> > > > > > topics
> >> > > > > > > >> (see
> >> > > > > > > >> > > the
> >> > > > > > > >> > > > > > > > rejected alternative item 2). This KIP will
> >> only
> >> > > > ensure
> >> > > > > > > log
> >> > > > > > > >> can
> >> > > > > > > >> > > be
> >> > > > > > > >> > > > > > > > compacted after a specified time-interval.
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > > As suggested by Dong, we will also enforce
> "
> >> > > > > > > >> > > max.compaction.lag.ms"
> >> > > > > > > >> > > > > is
> >> > > > > > > >> > > > > > > not
> >> > > > > > > >> > > > > > > > less than "min.compaction.lag.ms".
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > >
> >> > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-354
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP-354>
> >> > > > > > > >> > <
> >> https://cwiki.apache.org/confluence/display/KAFKA/KIP-354
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP-354
> >>
> >> > > > > > > >> > > > > Time-based
> >> > > > > > > >> > > > > > > log
> >> > > > > > > >> > > > > > > > compaction policy
> >> > > > > > > >> > > > > > > > <
> >> > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-354
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP-354>
> >> > > > > > > >> > <
> >> https://cwiki.apache.org/confluence/display/KAFKA/KIP-354
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP-354
> >>
> >> > > > > > > >> > > > > Time-based
> >> > > > > > > >> > > > > > > log compaction policy>
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > > On Tue, Aug 14, 2018 at 5:01 PM, xiongqi
> wu <
> >> > > > > > > >> > xiongqiwu@gmail.com
> >> > > > > > > >> > > >
> >> > > > > > > >> > > > > wrote:
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > > Per discussion with Dong, he made a very
> >> good
> >> > > > point
> >> > > > > > that
> >> > > > > > > >> if
> >> > > > > > > >> > > > > compaction
> >> > > > > > > >> > > > > > > > > and time based retention are both enabled
> >> on a
> >> > > > topic,
> >> > > > > > > the
> >> > > > > > > >> > > > > compaction
> >> > > > > > > >> > > > > > > > might
> >> > > > > > > >> > > > > > > > > prevent records from being deleted on
> time.
> >> > The
> >> > > > reason
> >> > > > > > > is
> >> > > > > > > >> > when
> >> > > > > > > >> > > > > > > compacting
> >> > > > > > > >> > > > > > > > > multiple segments into one single
> segment,
> >> the
> >> > > > newly
> >> > > > > > > >> created
> >> > > > > > > >> > > > > segment
> >> > > > > > > >> > > > > > > will
> >> > > > > > > >> > > > > > > > > have same lastmodified timestamp as
> latest
> >> > > > original
> >> > > > > > > >> segment.
> >> > > > > > > >> > We
> >> > > > > > > >> > > > > lose
> >> > > > > > > >> > > > > > > the
> >> > > > > > > >> > > > > > > > > timestamp of all original segments except
> >> the
> >> > > last
> >> > > > > > one.
> >> > > > > > > >> As a
> >> > > > > > > >> > > > > result,
> >> > > > > > > >> > > > > > > > > records might not be deleted as it should
> >> be
> >> > > > through
> >> > > > > > > time
> >> > > > > > > >> > based
> >> > > > > > > >> > > > > > > > retention.
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > > With the current KIP proposal, if we want
> >> to
> >> > > > ensure
> >> > > > > > > timely
> >> > > > > > > >> > > > > deletion, we
> >> > > > > > > >> > > > > > > > > have the following configurations:
> >> > > > > > > >> > > > > > > > > 1) enable time based log compaction only
> :
> >> > > > deletion is
> >> > > > > > > >> done
> >> > > > > > > >> > > > though
> >> > > > > > > >> > > > > > > > > overriding the same key
> >> > > > > > > >> > > > > > > > > 2) enable time based log retention only:
> >> > > deletion
> >> > > > is
> >> > > > > > > done
> >> > > > > > > >> > > though
> >> > > > > > > >> > > > > > > > > time-based retention
> >> > > > > > > >> > > > > > > > > 3) enable both log compaction and time
> >> based
> >> > > > > > retention:
> >> > > > > > > >> > > Deletion
> >> > > > > > > >> > > > > is not
> >> > > > > > > >> > > > > > > > > guaranteed.
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > > Not sure if we have use case 3 and also
> >> want
> >> > > > deletion
> >> > > > > > to
> >> > > > > > > >> > happen
> >> > > > > > > >> > > > on
> >> > > > > > > >> > > > > > > time.
> >> > > > > > > >> > > > > > > > > There are several options to address
> >> deletion
> >> > > > issue
> >> > > > > > when
> >> > > > > > > >> > enable
> >> > > > > > > >> > > > > both
> >> > > > > > > >> > > > > > > > > compaction and retention:
> >> > > > > > > >> > > > > > > > > A) During log compaction, looking into
> >> record
> >> > > > > > timestamp
> >> > > > > > > to
> >> > > > > > > >> > > delete
> >> > > > > > > >> > > > > > > expired
> >> > > > > > > >> > > > > > > > > records. This can be done in compaction
> >> logic
> >> > > > itself
> >> > > > > > or
> >> > > > > > > >> use
> >> > > > > > > >> > > > > > > > > AdminClient.deleteRecords() . But this
> >> assumes
> >> > > we
> >> > > > have
> >> > > > > > > >> record
> >> > > > > > > >> > > > > > > timestamp.
> >> > > > > > > >> > > > > > > > > B) retain the lastModifed time of
> original
> >> > > > segments
> >> > > > > > > during
> >> > > > > > > >> > log
> >> > > > > > > >> > > > > > > > compaction.
> >> > > > > > > >> > > > > > > > > This requires extra meta data to record
> the
> >> > > > > > information
> >> > > > > > > or
> >> > > > > > > >> > not
> >> > > > > > > >> > > > > grouping
> >> > > > > > > >> > > > > > > > > multiple segments into one during
> >> compaction.
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > > If we have use case 3 in general, I would
> >> > prefer
> >> > > > > > > solution
> >> > > > > > > >> A
> >> > > > > > > >> > and
> >> > > > > > > >> > > > > rely on
> >> > > > > > > >> > > > > > > > > record timestamp.
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > > Two questions:
> >> > > > > > > >> > > > > > > > > Do we have use case 3? Is it nice to have
> >> or
> >> > > must
> >> > > > > > have?
> >> > > > > > > >> > > > > > > > > If we have use case 3 and want to go with
> >> > > > solution A,
> >> > > > > > > >> should
> >> > > > > > > >> > we
> >> > > > > > > >> > > > > > > introduce
> >> > > > > > > >> > > > > > > > > a new configuration to enforce deletion
> by
> >> > > > timestamp?
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > > On Tue, Aug 14, 2018 at 1:52 PM, xiongqi
> >> wu <
> >> > > > > > > >> > > xiongqiwu@gmail.com
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > > > > > wrote:
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > >> Dong,
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> Thanks for the comment.
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> There are two retention policy: log
> >> > compaction
> >> > > > and
> >> > > > > > time
> >> > > > > > > >> > based
> >> > > > > > > >> > > > > > > retention.
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> Log compaction:
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> we have use cases to keep infinite
> >> retention
> >> > > of a
> >> > > > > > topic
> >> > > > > > > >> > (only
> >> > > > > > > >> > > > > > > > >> compaction). GDPR cares about deletion
> of
> >> PII
> >> > > > > > (personal
> >> > > > > > > >> > > > > identifiable
> >> > > > > > > >> > > > > > > > >> information) data.
> >> > > > > > > >> > > > > > > > >> Since Kafka doesn't know what records
> >> contain
> >> > > > PII, it
> >> > > > > > > >> relies
> >> > > > > > > >> > > on
> >> > > > > > > >> > > > > upper
> >> > > > > > > >> > > > > > > > >> layer to delete those records.
> >> > > > > > > >> > > > > > > > >> For those infinite retention uses uses,
> >> kafka
> >> > > > needs
> >> > > > > > to
> >> > > > > > > >> > > provide a
> >> > > > > > > >> > > > > way
> >> > > > > > > >> > > > > > > to
> >> > > > > > > >> > > > > > > > >> enforce compaction on time. This is what
> >> we
> >> > try
> >> > > > to
> >> > > > > > > >> address
> >> > > > > > > >> > in
> >> > > > > > > >> > > > this
> >> > > > > > > >> > > > > > > KIP.
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> Time based retention,
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> There are also use cases that users of
> >> Kafka
> >> > > > might
> >> > > > > > want
> >> > > > > > > >> to
> >> > > > > > > >> > > > expire
> >> > > > > > > >> > > > > all
> >> > > > > > > >> > > > > > > > >> their data.
> >> > > > > > > >> > > > > > > > >> In those cases, they can use time based
> >> > > > retention of
> >> > > > > > > >> their
> >> > > > > > > >> > > > topics.
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> Regarding your first question, if a user
> >> > wants
> >> > > to
> >> > > > > > > delete
> >> > > > > > > >> a
> >> > > > > > > >> > key
> >> > > > > > > >> > > > in
> >> > > > > > > >> > > > > the
> >> > > > > > > >> > > > > > > > >> log compaction topic, the user has to
> >> send a
> >> > > > deletion
> >> > > > > > > >> using
> >> > > > > > > >> > > the
> >> > > > > > > >> > > > > same
> >> > > > > > > >> > > > > > > > key.
> >> > > > > > > >> > > > > > > > >> Kafka only makes sure the deletion will
> >> > happen
> >> > > > under
> >> > > > > > a
> >> > > > > > > >> > certain
> >> > > > > > > >> > > > > time
> >> > > > > > > >> > > > > > > > >> periods (like 2 days/7 days).
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> Regarding your second question. In most
> >> > cases,
> >> > > we
> >> > > > > > might
> >> > > > > > > >> want
> >> > > > > > > >> > > to
> >> > > > > > > >> > > > > delete
> >> > > > > > > >> > > > > > > > >> all duplicated keys at the same time.
> >> > > > > > > >> > > > > > > > >> Compaction might be more efficient since
> >> we
> >> > > need
> >> > > > to
> >> > > > > > > scan
> >> > > > > > > >> the
> >> > > > > > > >> > > log
> >> > > > > > > >> > > > > and
> >> > > > > > > >> > > > > > > > find
> >> > > > > > > >> > > > > > > > >> all duplicates. However, the expected
> use
> >> > case
> >> > > > is to
> >> > > > > > > set
> >> > > > > > > >> the
> >> > > > > > > >> > > > time
> >> > > > > > > >> > > > > > > based
> >> > > > > > > >> > > > > > > > >> compaction interval on the order of
> days,
> >> and
> >> > > be
> >> > > > > > larger
> >> > > > > > > >> than
> >> > > > > > > >> > > > 'min
> >> > > > > > > >> > > > > > > > >> compaction lag". We don't want log
> >> compaction
> >> > > to
> >> > > > > > happen
> >> > > > > > > >> > > > frequently
> >> > > > > > > >> > > > > > > since
> >> > > > > > > >> > > > > > > > >> it is expensive. The purpose is to help
> >> low
> >> > > > > > production
> >> > > > > > > >> rate
> >> > > > > > > >> > > > topic
> >> > > > > > > >> > > > > to
> >> > > > > > > >> > > > > > > get
> >> > > > > > > >> > > > > > > > >> compacted on time. For the topic with
> >> > "normal"
> >> > > > > > incoming
> >> > > > > > > >> > > message
> >> > > > > > > >> > > > > > > message
> >> > > > > > > >> > > > > > > > >> rate, the "min dirty ratio" might have
> >> > > triggered
> >> > > > the
> >> > > > > > > >> > > compaction
> >> > > > > > > >> > > > > before
> >> > > > > > > >> > > > > > > > this
> >> > > > > > > >> > > > > > > > >> time based compaction policy takes
> effect.
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> Eno,
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> For your question, like I mentioned we
> >> have
> >> > > long
> >> > > > time
> >> > > > > > > >> > > retention
> >> > > > > > > >> > > > > use
> >> > > > > > > >> > > > > > > case
> >> > > > > > > >> > > > > > > > >> for log compacted topic, but we want to
> >> > provide
> >> > > > > > ability
> >> > > > > > > >> to
> >> > > > > > > >> > > > delete
> >> > > > > > > >> > > > > > > > certain
> >> > > > > > > >> > > > > > > > >> PII records on time.
> >> > > > > > > >> > > > > > > > >> Kafka itself doesn't know whether a
> record
> >> > > > contains
> >> > > > > > > >> > sensitive
> >> > > > > > > >> > > > > > > > information
> >> > > > > > > >> > > > > > > > >> and relies on the user for deletion.
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> On Mon, Aug 13, 2018 at 6:58 PM, Dong
> Lin
> >> <
> >> > > > > > > >> > > lindong28@gmail.com>
> >> > > > > > > >> > > > > > > wrote:
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >>> Hey Xiongqi,
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>> Thanks for the KIP. I have two
> questions
> >> > > > regarding
> >> > > > > > the
> >> > > > > > > >> > > use-case
> >> > > > > > > >> > > > > for
> >> > > > > > > >> > > > > > > > >>> meeting
> >> > > > > > > >> > > > > > > > >>> GDPR requirement.
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>> 1) If I recall correctly, one of the
> GDPR
> >> > > > > > requirement
> >> > > > > > > is
> >> > > > > > > >> > that
> >> > > > > > > >> > > > we
> >> > > > > > > >> > > > > can
> >> > > > > > > >> > > > > > > > not
> >> > > > > > > >> > > > > > > > >>> keep messages longer than e.g. 30 days
> in
> >> > > > storage
> >> > > > > > > (e.g.
> >> > > > > > > >> > > Kafka).
> >> > > > > > > >> > > > > Say
> >> > > > > > > >> > > > > > > > there
> >> > > > > > > >> > > > > > > > >>> exists a partition p0 which contains
> >> > message1
> >> > > > with
> >> > > > > > > key1
> >> > > > > > > >> and
> >> > > > > > > >> > > > > message2
> >> > > > > > > >> > > > > > > > with
> >> > > > > > > >> > > > > > > > >>> key2. And then user keeps producing
> >> messages
> >> > > > with
> >> > > > > > > >> key=key2
> >> > > > > > > >> > to
> >> > > > > > > >> > > > > this
> >> > > > > > > >> > > > > > > > >>> partition. Since message1 with key1 is
> >> never
> >> > > > > > > overridden,
> >> > > > > > > >> > > sooner
> >> > > > > > > >> > > > > or
> >> > > > > > > >> > > > > > > > later
> >> > > > > > > >> > > > > > > > >>> we
> >> > > > > > > >> > > > > > > > >>> will want to delete message1 and keep
> the
> >> > > latest
> >> > > > > > > message
> >> > > > > > > >> > with
> >> > > > > > > >> > > > > > > key=key2.
> >> > > > > > > >> > > > > > > > >>> But
> >> > > > > > > >> > > > > > > > >>> currently it looks like log compact
> >> logic in
> >> > > > Kafka
> >> > > > > > > will
> >> > > > > > > >> > > always
> >> > > > > > > >> > > > > put
> >> > > > > > > >> > > > > > > > these
> >> > > > > > > >> > > > > > > > >>> messages in the same segment. Will this
> >> be
> >> > an
> >> > > > issue?
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>> 2) The current KIP intends to provide
> the
> >> > > > capability
> >> > > > > > > to
> >> > > > > > > >> > > delete
> >> > > > > > > >> > > > a
> >> > > > > > > >> > > > > > > given
> >> > > > > > > >> > > > > > > > >>> message in log compacted topic. Does
> such
> >> > > > use-case
> >> > > > > > > also
> >> > > > > > > >> > > require
> >> > > > > > > >> > > > > Kafka
> >> > > > > > > >> > > > > > > > to
> >> > > > > > > >> > > > > > > > >>> keep the messages produced before the
> >> given
> >> > > > message?
> >> > > > > > > If
> >> > > > > > > >> > yes,
> >> > > > > > > >> > > > > then we
> >> > > > > > > >> > > > > > > > can
> >> > > > > > > >> > > > > > > > >>> probably just use
> >> > AdminClient.deleteRecords()
> >> > > or
> >> > > > > > > >> time-based
> >> > > > > > > >> > > log
> >> > > > > > > >> > > > > > > > retention
> >> > > > > > > >> > > > > > > > >>> to meet the use-case requirement. If
> no,
> >> do
> >> > > you
> >> > > > know
> >> > > > > > > >> what
> >> > > > > > > >> > is
> >> > > > > > > >> > > > the
> >> > > > > > > >> > > > > > > GDPR's
> >> > > > > > > >> > > > > > > > >>> requirement on time-to-deletion after
> >> user
> >> > > > > > explicitly
> >> > > > > > > >> > > requests
> >> > > > > > > >> > > > > the
> >> > > > > > > >> > > > > > > > >>> deletion
> >> > > > > > > >> > > > > > > > >>> (e.g. 1 hour, 1 day, 7 day)?
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>> Thanks,
> >> > > > > > > >> > > > > > > > >>> Dong
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>> On Mon, Aug 13, 2018 at 3:44 PM,
> xiongqi
> >> wu
> >> > <
> >> > > > > > > >> > > > xiongqiwu@gmail.com
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > > > wrote:
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>> > Hi Eno,
> >> > > > > > > >> > > > > > > > >>> >
> >> > > > > > > >> > > > > > > > >>> > The GDPR request we are getting here
> at
> >> > > > linkedin
> >> > > > > > is
> >> > > > > > > >> if we
> >> > > > > > > >> > > > get a
> >> > > > > > > >> > > > > > > > >>> request to
> >> > > > > > > >> > > > > > > > >>> > delete a record through a null key
> on a
> >> > log
> >> > > > > > > compacted
> >> > > > > > > >> > > topic,
> >> > > > > > > >> > > > > > > > >>> > we want to delete the record via
> >> > compaction
> >> > > > in a
> >> > > > > > > given
> >> > > > > > > >> > time
> >> > > > > > > >> > > > > period
> >> > > > > > > >> > > > > > > > >>> like 2
> >> > > > > > > >> > > > > > > > >>> > days (whatever is required by the
> >> policy).
> >> > > > > > > >> > > > > > > > >>> >
> >> > > > > > > >> > > > > > > > >>> > There might be other issues (such as
> >> > orphan
> >> > > > log
> >> > > > > > > >> segments
> >> > > > > > > >> > > > under
> >> > > > > > > >> > > > > > > > certain
> >> > > > > > > >> > > > > > > > >>> > conditions) that lead to GDPR problem
> >> but
> >> > > > they are
> >> > > > > > > >> more
> >> > > > > > > >> > > like
> >> > > > > > > >> > > > > > > > >>> something we
> >> > > > > > > >> > > > > > > > >>> > need to fix anyway regardless of
> GDPR.
> >> > > > > > > >> > > > > > > > >>> >
> >> > > > > > > >> > > > > > > > >>> >
> >> > > > > > > >> > > > > > > > >>> > -- Xiongqi (Wesley) Wu
> >> > > > > > > >> > > > > > > > >>> >
> >> > > > > > > >> > > > > > > > >>> > On Mon, Aug 13, 2018 at 2:56 PM, Eno
> >> > > Thereska
> >> > > > <
> >> > > > > > > >> > > > > > > > eno.thereska@gmail.com>
> >> > > > > > > >> > > > > > > > >>> > wrote:
> >> > > > > > > >> > > > > > > > >>> >
> >> > > > > > > >> > > > > > > > >>> > > Hello,
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > > Thanks for the KIP. I'd like to
> see a
> >> > more
> >> > > > > > precise
> >> > > > > > > >> > > > > definition of
> >> > > > > > > >> > > > > > > > what
> >> > > > > > > >> > > > > > > > >>> > part
> >> > > > > > > >> > > > > > > > >>> > > of GDPR you are targeting as well
> as
> >> > some
> >> > > > sort
> >> > > > > > of
> >> > > > > > > >> > > > > verification
> >> > > > > > > >> > > > > > > that
> >> > > > > > > >> > > > > > > > >>> this
> >> > > > > > > >> > > > > > > > >>> > > KIP actually addresses the problem.
> >> > Right
> >> > > > now I
> >> > > > > > > find
> >> > > > > > > >> > > this a
> >> > > > > > > >> > > > > bit
> >> > > > > > > >> > > > > > > > >>> vague:
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > > "Ability to delete a log message
> >> through
> >> > > > > > > compaction
> >> > > > > > > >> in
> >> > > > > > > >> > a
> >> > > > > > > >> > > > > timely
> >> > > > > > > >> > > > > > > > >>> manner
> >> > > > > > > >> > > > > > > > >>> > has
> >> > > > > > > >> > > > > > > > >>> > > become an important requirement in
> >> some
> >> > > use
> >> > > > > > cases
> >> > > > > > > >> > (e.g.,
> >> > > > > > > >> > > > > GDPR)"
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > > Is there any guarantee that after
> >> this
> >> > KIP
> >> > > > the
> >> > > > > > > GDPR
> >> > > > > > > >> > > problem
> >> > > > > > > >> > > > > is
> >> > > > > > > >> > > > > > > > >>> solved or
> >> > > > > > > >> > > > > > > > >>> > do
> >> > > > > > > >> > > > > > > > >>> > > we need to do something else as
> well,
> >> > > e.g.,
> >> > > > more
> >> > > > > > > >> KIPs?
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > > Thanks
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > > Eno
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > > On Thu, Aug 9, 2018 at 4:18 PM,
> >> xiongqi
> >> > > wu <
> >> > > > > > > >> > > > > xiongqiwu@gmail.com>
> >> > > > > > > >> > > > > > > > >>> wrote:
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> > > > Hi Kafka,
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > > > > > > >> > > > > > > > >>> > > > This KIP tries to address GDPR
> >> concern
> >> > > to
> >> > > > > > > fulfill
> >> > > > > > > >> > > > deletion
> >> > > > > > > >> > > > > > > > request
> >> > > > > > > >> > > > > > > > >>> on
> >> > > > > > > >> > > > > > > > >>> > > time
> >> > > > > > > >> > > > > > > > >>> > > > through time-based log compaction
> >> on a
> >> > > > > > > compaction
> >> > > > > > > >> > > enabled
> >> > > > > > > >> > > > > > > topic:
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > > > > > > >> > https://cwiki.apache.org/confluence/display/KAFKA/KIP-
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP->
> >> > > > > > > >> > <
> https://cwiki.apache.org/confluence/display/KAFKA/KIP-
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP->>
> >> > > > > > > >> > > > > > > > <
> >> > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP->
> >> > > > > > > >> > <
> https://cwiki.apache.org/confluence/display/KAFKA/KIP-
> >> > > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/KIP->>>
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > 354%3A+Time-based+log+compaction+policy
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > > > > > > >> > > > > > > > >>> > > > Any feedback will be appreciated.
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > > > > > > >> > > > > > > > >>> > > > Xiongqi (Wesley) Wu
> >> > > > > > > >> > > > > > > > >>> > > >
> >> > > > > > > >> > > > > > > > >>> > >
> >> > > > > > > >> > > > > > > > >>> >
> >> > > > > > > >> > > > > > > > >>>
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >> --
> >> > > > > > > >> > > > > > > > >> Xiongqi (Wesley) Wu
> >> > > > > > > >> > > > > > > > >>
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > > > --
> >> > > > > > > >> > > > > > > > > Xiongqi (Wesley) Wu
> >> > > > > > > >> > > > > > > > >
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > > > --
> >> > > > > > > >> > > > > > > > Xiongqi (Wesley) Wu
> >> > > > > > > >> > > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > --
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > Brett Rann
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > Senior DevOps Engineer
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > Zendesk International Ltd
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > 395 Collins Street, Melbourne VIC 3000
> >> Australia
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > > > Mobile: +61 (0) 418 826 017
> >> > > > > > > >> > > > > > >
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > > > --
> >> > > > > > > >> > > > > > Xiongqi (Wesley) Wu
> >> > > > > > > >> > > > > >
> >> > > > > > > >> > > > >
> >> > > > > > > >> > > >
> >> > > > > > > >> > > >
> >> > > > > > > >> > > >
> >> > > > > > > >> > > > --
> >> > > > > > > >> > > > Xiongqi (Wesley) Wu
> >> > > > > > > >> > > >
> >> > > > > > > >> > >
> >> > > > > > > >> >
> >> > > > > > > >> >
> >> > > > > > > >> >
> >> > > > > > > >> > --
> >> > > > > > > >> > Xiongqi (Wesley) Wu
> >> > > > > > > >> >
> >> > > > > > > >>
> >> > > > > > > >>
> >> > > > > > > >> --
> >> > > > > > > >>
> >> > > > > > > >> Brett Rann
> >> > > > > > > >>
> >> > > > > > > >> Senior DevOps Engineer
> >> > > > > > > >>
> >> > > > > > > >>
> >> > > > > > > >> Zendesk International Ltd
> >> > > > > > > >>
> >> > > > > > > >> 395 Collins Street, Melbourne VIC 3000 Australia
> >> > > > > > > >>
> >> > > > > > > >> Mobile: +61 (0) 418 826 017
> >> > > > > > > >>
> >> > > > > > > >
> >> > > > > > >
> >> > > > > > >
> >> > > > > > > --
> >> > > > > > > Xiongqi (Wesley) Wu
> >> > > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > > --
> >> > > > > >
> >> > > > > > Brett Rann
> >> > > > > >
> >> > > > > > Senior DevOps Engineer
> >> > > > > >
> >> > > > > >
> >> > > > > > Zendesk International Ltd
> >> > > > > >
> >> > > > > > 395 Collins Street, Melbourne VIC 3000 Australia
> >> > > > > >
> >> > > > > > Mobile: +61 (0) 418 826 017
> >> > > > > >
> >> > > >
> >> > >
> >> > >
> >> > > --
> >> > > -Regards,
> >> > > Mayuresh R. Gharat
> >> > > (862) 250-7125
> >> > >
> >> >
> >>
> >
>

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