Thanks Joel. Tracking the delay at second granularity makes sense I have updated KIP.
Xiongqi (Wesley) Wu On Fri, Nov 9, 2018 at 5:05 PM Joel Koshy <jjkosh...@gmail.com> wrote: > +1 with one suggestion on the proposed metric. You should probably include > the unit. So for e.g., max-compaction-delay-secs. > > Joel > > On Tue, Nov 6, 2018 at 5:30 PM xiongqi wu <xiongq...@gmail.com> wrote: > > > bump > > Xiongqi (Wesley) Wu > > > > > > On Thu, Sep 27, 2018 at 4:20 PM xiongqi wu <xiongq...@gmail.com> wrote: > > > > > > > > Thanks Eno, Brett, Dong, Guozhang, Colin, and Xiaohe for feedback. > > > Can I have more feedback or VOTE on this KIP? > > > > > > > > > Xiongqi (Wesley) Wu > > > > > > > > > On Wed, Sep 19, 2018 at 10:52 AM xiongqi wu <xiongq...@gmail.com> > wrote: > > > > > >> Any other votes or comments? > > >> > > >> Xiongqi (Wesley) Wu > > >> > > >> > > >> On Tue, Sep 11, 2018 at 11:45 AM xiongqi wu <xiongq...@gmail.com> > > wrote: > > >> > > >>> Yes, more votes and code review. > > >>> > > >>> Xiongqi (Wesley) Wu > > >>> > > >>> > > >>> On Mon, Sep 10, 2018 at 11:37 PM Brett Rann > <br...@zendesk.com.invalid > > > > > >>> wrote: > > >>> > > >>>> +1 (non binding) from on 0 then, and on the KIP. > > >>>> > > >>>> Where do we go from here? More votes? > > >>>> > > >>>> On Tue, Sep 11, 2018 at 5:34 AM Colin McCabe <cmcc...@apache.org> > > >>>> wrote: > > >>>> > > >>>> > On Mon, Sep 10, 2018, at 11:44, xiongqi wu wrote: > > >>>> > > Thank you for comments. I will use '0' for now. > > >>>> > > > > >>>> > > If we create topics through admin client in the future, we might > > >>>> perform > > >>>> > > some useful checks. (but the assumption is all brokers in the > same > > >>>> > cluster > > >>>> > > have the same default configurations value, otherwise,it might > > >>>> still be > > >>>> > > tricky to do such cross validation check.) > > >>>> > > > >>>> > This isn't something that we might do in the future-- this is > > >>>> something we > > >>>> > are doing now. We already have Create Topic policies which are > > >>>> enforced by > > >>>> > the broker. Check KIP-108 and KIP-170 for details. This is one of > > the > > >>>> > motivations for getting rid of direct ZK access-- making sure that > > >>>> these > > >>>> > policies are applied. > > >>>> > > > >>>> > I agree that having different configurations on different brokers > > can > > >>>> be > > >>>> > confusing and frustrating . That's why more configurations are > being > > >>>> made > > >>>> > dynamic using KIP-226. Dynamic configurations are stored centrally > > in > > >>>> ZK, > > >>>> > so they are the same on all brokers (modulo propagation delays). > In > > >>>> any > > >>>> > case, this is a general issue, not specific to "create topics". > > >>>> > > > >>>> > cheers, > > >>>> > Colin > > >>>> > > > >>>> > > > >>>> > > > > >>>> > > > > >>>> > > Xiongqi (Wesley) Wu > > >>>> > > > > >>>> > > > > >>>> > > On Mon, Sep 10, 2018 at 11:15 AM Colin McCabe < > cmcc...@apache.org > > > > > >>>> > wrote: > > >>>> > > > > >>>> > > > I don't have a strong opinion. But I think we should probably > be > > >>>> > > > consistent with how segment.ms works, and just use 0. > > >>>> > > > > > >>>> > > > best, > > >>>> > > > Colin > > >>>> > > > > > >>>> > > > > > >>>> > > > On Wed, Sep 5, 2018, at 21:19, Brett Rann wrote: > > >>>> > > > > OK thanks for that clarification. I see why you're > > uncomfortable > > >>>> > with 0 > > >>>> > > > now. > > >>>> > > > > > > >>>> > > > > I'm not really fussed. I just prefer consistency in > > >>>> configuration > > >>>> > > > options. > > >>>> > > > > > > >>>> > > > > Personally I lean towards treating 0 and 1 similarly in that > > >>>> > scenario, > > >>>> > > > > because it favours the person thinking about setting the > > >>>> > configurations, > > >>>> > > > > and a person doesn't care about a 1ms edge case especially > > when > > >>>> the > > >>>> > > > context > > >>>> > > > > is the true minimum is tied to the log cleaner cadence. > > >>>> > > > > > > >>>> > > > > Introducing 0 to mean "disabled" because there is some > > >>>> uniquness in > > >>>> > > > > segment.ms not being able to be set to 0, reduces > > configuration > > >>>> > > > consistency > > >>>> > > > > in favour of capturing a MS gap in an edge case that nobody > > >>>> would > > >>>> > ever > > >>>> > > > > notice. For someone to understand why everywhere else -1 is > > >>>> used to > > >>>> > > > > disable, but here 0 is used, they would need to learn about > > >>>> > segment.ms > > >>>> > > > > having a 1ms minimum and then after learning would think > "who > > >>>> cares > > >>>> > about > > >>>> > > > > 1ms?" in this context. I would anyway :) > > >>>> > > > > > > >>>> > > > > my 2c anyway. Will again defer to majority. Curious which > way > > >>>> Colin > > >>>> > falls > > >>>> > > > > now. > > >>>> > > > > > > >>>> > > > > Don't want to spend more time on this though, It's well into > > >>>> > > > bikeshedding > > >>>> > > > > territory now. :) > > >>>> > > > > > > >>>> > > > > > > >>>> > > > > > > >>>> > > > > On Thu, Sep 6, 2018 at 1:31 PM xiongqi wu < > > xiongq...@gmail.com> > > >>>> > wrote: > > >>>> > > > > > > >>>> > > > > > I want to honor the minimum value of segment.ms (which is > > >>>> 1ms) to > > >>>> > > > force > > >>>> > > > > > roll an active segment. > > >>>> > > > > > So if we set "max.compaction.lag.ms" any value > 0, the > > >>>> minimum of > > >>>> > > > > > max.compaction.lag.ms and segment.ms will be used to seal > > an > > >>>> > active > > >>>> > > > > > segment. > > >>>> > > > > > > > >>>> > > > > > If we set max.compaction.lag.ms to 0, the current > > >>>> implementation > > >>>> > will > > >>>> > > > > > treat it as disabled. > > >>>> > > > > > > > >>>> > > > > > It is a little bit weird to treat max.compaction.lag=0 the > > >>>> same as > > >>>> > > > > > max.compaction.lag=1. > > >>>> > > > > > > > >>>> > > > > > There might be a reason why we set the minimum of > > segment.ms > > >>>> to 1, > > >>>> > > > and I > > >>>> > > > > > don't want to break this assumption. > > >>>> > > > > > > > >>>> > > > > > > > >>>> > > > > > > > >>>> > > > > > Xiongqi (Wesley) Wu > > >>>> > > > > > > > >>>> > > > > > > > >>>> > > > > > On Wed, Sep 5, 2018 at 7:54 PM Brett Rann > > >>>> > <br...@zendesk.com.invalid> > > >>>> > > > > > wrote: > > >>>> > > > > > > > >>>> > > > > > > You're rolling a new segment if the condition is met > > right? > > >>>> So > > >>>> > I'm > > >>>> > > > > > > struggling to understand the relevance of segment.ms > > here. > > >>>> > Maybe an > > >>>> > > > > > > example > > >>>> > > > > > > would help my understanding: > > >>>> > > > > > > > > >>>> > > > > > > segment.ms=9999999 > > >>>> > > > > > > *min.cleanable.dirty.ratio=1* > > >>>> > > > > > > max.compaction.lag.ms=1 > > >>>> > > > > > > > > >>>> > > > > > > When a duplicate message comes in, after 1ms the topic > > >>>> should be > > >>>> > > > eligible > > >>>> > > > > > > for compaction when the log compaction thread gets > around > > to > > >>>> > > > evaluating > > >>>> > > > > > the > > >>>> > > > > > > topic. > > >>>> > > > > > > > > >>>> > > > > > > if we have > > >>>> > > > > > > segment.ms=9999999 > > >>>> > > > > > > *min.cleanable.dirty.ratio=1* > > >>>> > > > > > > max.compaction.lag.ms=0 > > >>>> > > > > > > > > >>>> > > > > > > When a duplicate message comes in, after 0ms the topic > > >>>> should be > > >>>> > > > eligible > > >>>> > > > > > > for compaction when the log compaction thread gets > around > > to > > >>>> > > > evaluating > > >>>> > > > > > the > > >>>> > > > > > > topic. > > >>>> > > > > > > > > >>>> > > > > > > In both of those cases the change would mean a new > segment > > >>>> is > > >>>> > rolled > > >>>> > > > so > > >>>> > > > > > the > > >>>> > > > > > > new message would be part of the compaction task. 0 and > 1 > > >>>> are > > >>>> > > > practically > > >>>> > > > > > > the same meaning since neither is providing an actual > > >>>> guarantee > > >>>> > at > > >>>> > > > such > > >>>> > > > > > low > > >>>> > > > > > > MS settings, but effectively tying it to both the > > frequency > > >>>> of > > >>>> > the > > >>>> > > > log > > >>>> > > > > > > cleaner running and the priority of the given topic > being > > >>>> the > > >>>> > highest > > >>>> > > > > > > priority of all topics that are evaluated for cleaning > on > > >>>> the > > >>>> > next > > >>>> > > > cycle. > > >>>> > > > > > > You've captured that nuance with careful "skipped" > wording > > >>>> in > > >>>> > the KIP > > >>>> > > > > > > here "controls > > >>>> > > > > > > the max time interval a message/segment can be skipped > for > > >>>> log > > >>>> > > > > > compaction". > > >>>> > > > > > > > > >>>> > > > > > > How is 0 different to 1, practically? And how is it > > >>>> relating to > > >>>> > > > > > segment.ms > > >>>> > > > > > > ? > > >>>> > > > > > > Is it that you're proposing to have 0 mean "use > > segment.ms > > >>>> > > > instead?" as > > >>>> > > > > > a > > >>>> > > > > > > kind of third option? > > >>>> > > > > > > > > >>>> > > > > > > > > >>>> > > > > > > > > >>>> > > > > > > On Thu, Sep 6, 2018 at 11:34 AM xiongqi wu < > > >>>> xiongq...@gmail.com> > > >>>> > > > wrote: > > >>>> > > > > > > > > >>>> > > > > > > > To make it clear, > > >>>> > > > > > > > I don't against using -1 as disabled, but we need to > > come > > >>>> up > > >>>> > with > > >>>> > > > the > > >>>> > > > > > > > meaning of "0". > > >>>> > > > > > > > If "0" means immediate compaction, but the actual > > >>>> compaction > > >>>> > lag > > >>>> > > > will > > >>>> > > > > > be > > >>>> > > > > > > > segment.ms. > > >>>> > > > > > > > It has longer lag than setting the value to be half of > > >>>> > segment.ms. > > >>>> > > > > > > > We cannot provide "0" as max compaction lag. > > >>>> > > > > > > > > > >>>> > > > > > > > Here are two options. > > >>>> > > > > > > > Option 1: > > >>>> > > > > > > > Keep 0 as disabled > > >>>> > > > > > > > Option 2: > > >>>> > > > > > > > -1 (disabled), 0 (max compaction lag = segment.ms), > and > > >>>> > others. > > >>>> > > > > > > > > > >>>> > > > > > > > > > >>>> > > > > > > > > > >>>> > > > > > > > Xiongqi (Wesley) Wu > > >>>> > > > > > > > > > >>>> > > > > > > > > > >>>> > > > > > > > On Wed, Sep 5, 2018 at 5:49 PM Brett Rann > > >>>> > > > <br...@zendesk.com.invalid> > > >>>> > > > > > > > wrote: > > >>>> > > > > > > > > > >>>> > > > > > > > > -1 is consistent as "special" with these settings > for > > >>>> > example: > > >>>> > > > > > > > > > > >>>> > > > > > > > > log.retention.bytes > > >>>> > > > > > > > > socket.received.buffer.bytes > > >>>> > > > > > > > > socket.send.buffer.bytes > > >>>> > > > > > > > > queued.max.request.bytes > > >>>> > > > > > > > > retention.bytes > > >>>> > > > > > > > > retention.ms > > >>>> > > > > > > > > > > >>>> > > > > > > > > and acks. > > >>>> > > > > > > > > > > >>>> > > > > > > > > Where it may mean no limit, use OS defaults, max > > (acks), > > >>>> > etc. I > > >>>> > > > don't > > >>>> > > > > > > see > > >>>> > > > > > > > > much convention of 0 meaning those things. > > >>>> > > > > > > > > > > >>>> > > > > > > > > There are some NULLs but it seems convetion there is > > >>>> NULL is > > >>>> > used > > >>>> > > > > > where > > >>>> > > > > > > > > there's another setting in the hierarchy that would > be > > >>>> used > > >>>> > > > instead. > > >>>> > > > > > > > > > > >>>> > > > > > > > > > > >>>> > > > > > > > > > > >>>> > > > > > > > > > > >>>> > > > > > > > > On Thu, Sep 6, 2018 at 10:42 AM Brett Rann < > > >>>> > br...@zendesk.com> > > >>>> > > > > > wrote: > > >>>> > > > > > > > > > > >>>> > > > > > > > > > If segment.ms can't be set to 0, then we're not > > being > > >>>> > > > consistent > > >>>> > > > > > > > > > by using 0 for this new setting? I throw out -1 > for > > >>>> > > > consideration > > >>>> > > > > > > > > > again :) > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > On Thu, Sep 6, 2018 at 10:03 AM xiongqi wu < > > >>>> > > > xiongq...@gmail.com> > > >>>> > > > > > > > wrote: > > >>>> > > > > > > > > > > > >>>> > > > > > > > > >> Thanks. I will document after PR is merged. > > >>>> > > > > > > > > >> > > >>>> > > > > > > > > >> BTW, Kafka enforce the minimum of "segment.ms" > to > > >>>> 1, we > > >>>> > > > cannot > > >>>> > > > > > set > > >>>> > > > > > > " > > >>>> > > > > > > > > >> segment.ms" to 0. > > >>>> > > > > > > > > >> > > >>>> > > > > > > > > >> I also updated the title of this KIP. > > >>>> > > > > > > > > >> > > >>>> > > > > > > > > >> Xiongqi (Wesley) Wu > > >>>> > > > > > > > > >> > > >>>> > > > > > > > > >> > > >>>> > > > > > > > > >> On Wed, Sep 5, 2018 at 4:34 PM Brett Rann > > >>>> > > > > > <br...@zendesk.com.invalid > > >>>> > > > > > > > > > >>>> > > > > > > > > >> wrote: > > >>>> > > > > > > > > >> > > >>>> > > > > > > > > >> > I withdraw my comments on -1 since i'm in the > > >>>> minority. > > >>>> > :) > > >>>> > > > Can > > >>>> > > > > > we > > >>>> > > > > > > > > >> > make sure 0 gets documented as meaning disabled > > >>>> here: > > >>>> > > > > > > > > >> > > > >>>> https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs> > > >>>> > > > > > <https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs>> > > >>>> > > > > > > > < > https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs> > > >>>> > > > > > <https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs>>> > > >>>> > > > > > > > > >> < > > >>>> https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs> > > >>>> > > > > > <https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs>> > > >>>> > > > > > > > < > https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs> > > >>>> > > > > > <https://kafka.apache.org/documentation/#brokerconfigs > > >>>> > <https://kafka.apache.org/documentation/#brokerconfigs>>>> ? > > >>>> > > > > > > > > >> > And while there it would be good if segment.ms > > is > > >>>> > > > documented > > >>>> > > > > > > > > >> > that 0 is disabled too. (there's some hierarchy > > of > > >>>> > configs > > >>>> > > > for > > >>>> > > > > > > that > > >>>> > > > > > > > > too > > >>>> > > > > > > > > >> > if its not set and null for others means > > disabled!) > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > On Thu, Sep 6, 2018 at 4:44 AM xiongqi wu < > > >>>> > > > xiongq...@gmail.com> > > >>>> > > > > > > > > wrote: > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > > If we use 0 to indicate immediate compaction, > > the > > >>>> > > > compaction > > >>>> > > > > > lag > > >>>> > > > > > > > is > > >>>> > > > > > > > > >> > > determined by segment.ms in worst case. If > > >>>> segment.ms > > >>>> > is > > >>>> > > > 24 > > >>>> > > > > > > > hours, > > >>>> > > > > > > > > >> > > "immediate compaction" is a weaker guarantee > > than > > >>>> > setting > > >>>> > > > any > > >>>> > > > > > > > value > > >>>> > > > > > > > > >> less > > >>>> > > > > > > > > >> > > than 24 hours. By the definition of "max > > >>>> compaction > > >>>> > lag", > > >>>> > > > we > > >>>> > > > > > > > cannot > > >>>> > > > > > > > > >> have > > >>>> > > > > > > > > >> > > zero lag. So I use 0 to indicate "disable". > > >>>> > > > > > > > > >> > > > > >>>> > > > > > > > > >> > > > > >>>> > > > > > > > > >> > > > > >>>> > > > > > > > > >> > > Xiongqi (Wesley) Wu > > >>>> > > > > > > > > >> > > > > >>>> > > > > > > > > >> > > > > >>>> > > > > > > > > >> > > On Wed, Sep 5, 2018 at 8:34 AM Colin McCabe < > > >>>> > > > > > cmcc...@apache.org > > >>>> > > > > > > > > > >>>> > > > > > > > > >> wrote: > > >>>> > > > > > > > > >> > > > > >>>> > > > > > > > > >> > > > On Tue, Sep 4, 2018, at 22:11, Brett Rann > > >>>> wrote: > > >>>> > > > > > > > > >> > > > > > That's a fair point. We should make 0 = > > >>>> > disable, to > > >>>> > > > be > > >>>> > > > > > > > > >> consistent > > >>>> > > > > > > > > >> > > with > > >>>> > > > > > > > > >> > > > > the other settings. > > >>>> > > > > > > > > >> > > > > > > >>>> > > > > > > > > >> > > > > -1 is used elsewhere for disable and when > > >>>> seeing > > >>>> > it > > >>>> > > > in a > > >>>> > > > > > > > config > > >>>> > > > > > > > > >> it's > > >>>> > > > > > > > > >> > > > clear > > >>>> > > > > > > > > >> > > > > that it's a special meaning. 0 doesn't > have > > >>>> to > > >>>> > mean > > >>>> > > > > > instant, > > >>>> > > > > > > > it > > >>>> > > > > > > > > >> just > > >>>> > > > > > > > > >> > > > means > > >>>> > > > > > > > > >> > > > > as quickly as possible. I don't think 0 > is > > >>>> > intuitive > > >>>> > > > for > > >>>> > > > > > > > > disabled > > >>>> > > > > > > > > >> and > > >>>> > > > > > > > > >> > > it > > >>>> > > > > > > > > >> > > > > will be confusing. I wasn't aware > > segment.ms=0 > > >>>> == > > >>>> > > > > > disabled, > > >>>> > > > > > > > > but I > > >>>> > > > > > > > > >> > > think > > >>>> > > > > > > > > >> > > > > that is also unintuitive. > > >>>> > > > > > > > > >> > > > > > >>>> > > > > > > > > >> > > > I think there is an argument for keeping > > these > > >>>> two > > >>>> > > > > > > > configurations > > >>>> > > > > > > > > >> > > > consistent, since they are so similar. I > > agree > > >>>> that > > >>>> > 0 > > >>>> > > > was an > > >>>> > > > > > > > > >> > unfortunate > > >>>> > > > > > > > > >> > > > choice., > > >>>> > > > > > > > > >> > > > > > >>>> > > > > > > > > >> > > > best, > > >>>> > > > > > > > > >> > > > Colin > > >>>> > > > > > > > > >> > > > > > >>>> > > > > > > > > >> > > > > > > >>>> > > > > > > > > >> > > > > On Wed, Sep 5, 2018 at 11:38 AM Colin > > McCabe > > >>>> < > > >>>> > > > > > > > > cmcc...@apache.org> > > >>>> > > > > > > > > >> > > wrote: > > >>>> > > > > > > > > >> > > > > > > >>>> > > > > > > > > >> > > > > > On Tue, Sep 4, 2018, at 17:47, xiongqi > wu > > >>>> wrote: > > >>>> > > > > > > > > >> > > > > > > Colin, > > >>>> > > > > > > > > >> > > > > > > Thank you for comments. > > >>>> > > > > > > > > >> > > > > > > see my inline reply below. > > >>>> > > > > > > > > >> > > > > > > > > >>>> > > > > > > > > >> > > > > > > Xiongqi (Wesley) Wu > > >>>> > > > > > > > > >> > > > > > > > > >>>> > > > > > > > > >> > > > > > > > > >>>> > > > > > > > > >> > > > > > > On Tue, Sep 4, 2018 at 5:24 PM Colin > > >>>> McCabe < > > >>>> > > > > > > > > >> cmcc...@apache.org> > > >>>> > > > > > > > > >> > > > wrote: > > >>>> > > > > > > > > >> > > > > > > > > >>>> > > > > > > > > >> > > > > > > > Hi Xiongqi, > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > Thanks for this KIP. > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > The name seems a bit ambiguous. Our > > >>>> > compaction > > >>>> > > > > > > policies > > >>>> > > > > > > > > are > > >>>> > > > > > > > > >> > > already > > >>>> > > > > > > > > >> > > > > > > > time-based, after all. It seems > like > > >>>> this > > >>>> > > > change is > > >>>> > > > > > > > > focused > > >>>> > > > > > > > > >> > > around > > >>>> > > > > > > > > >> > > > > > adding > > >>>> > > > > > > > > >> > > > > > > > a “max.compaction.lag.ms." Perhaps > > >>>> the KIP > > >>>> > > > title > > >>>> > > > > > > should > > >>>> > > > > > > > > be > > >>>> > > > > > > > > >> > > > something > > >>>> > > > > > > > > >> > > > > > > > like "add maximum compaction lag > > time"? > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > ==========> sure. I will change the > > >>>> title. > > >>>> > > > > > > > > >> > > > > > > > > >>>> > > > > > > > > >> > > > > > > > The active segment is forced to > roll > > >>>> when > > >>>> > > > either " > > >>>> > > > > > > > > >> > > > > > max.compaction.lag.ms" > > >>>> > > > > > > > > >> > > > > > > > > or "segment.ms" (log.roll.ms and > > >>>> > > > log.roll.hours) > > >>>> > > > > > > has > > >>>> > > > > > > > > >> > reached. > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > If the max.compaction.lag.ms is > low, > > >>>> it > > >>>> > seems > > >>>> > > > like > > >>>> > > > > > > > > segments > > >>>> > > > > > > > > >> > will > > >>>> > > > > > > > > >> > > > be > > >>>> > > > > > > > > >> > > > > > > > rolled very frequently. This can > be a > > >>>> > source of > > >>>> > > > > > > problems > > >>>> > > > > > > > > in > > >>>> > > > > > > > > >> the > > >>>> > > > > > > > > >> > > > > > cluster, > > >>>> > > > > > > > > >> > > > > > > > since creating many different small > > log > > >>>> > segments > > >>>> > > > > > > > consumes > > >>>> > > > > > > > > a > > >>>> > > > > > > > > >> > huge > > >>>> > > > > > > > > >> > > > > > amount of > > >>>> > > > > > > > > >> > > > > > > > cluster resources. Therefore, I > would > > >>>> > suggest > > >>>> > > > > > adding a > > >>>> > > > > > > > > >> > > broker-level > > >>>> > > > > > > > > >> > > > > > > > configuration which allows us to > set > > a > > >>>> > minimum > > >>>> > > > value > > >>>> > > > > > > for > > >>>> > > > > > > > > >> > > > > > > > max.compaction.lag.ms. If we let > > >>>> users set > > >>>> > it > > >>>> > > > on a > > >>>> > > > > > > > > >> per-topic > > >>>> > > > > > > > > >> > > > basis, > > >>>> > > > > > > > > >> > > > > > > > someone could set a value of 1 ms > or > > >>>> > something, > > >>>> > > > and > > >>>> > > > > > > > cause > > >>>> > > > > > > > > >> > chaos. > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > =========> this applies to > > segment.ms > > >>>> as > > >>>> > well. > > >>>> > > > > > Today > > >>>> > > > > > > > > users > > >>>> > > > > > > > > >> can > > >>>> > > > > > > > > >> > > > set " > > >>>> > > > > > > > > >> > > > > > > segment.ms" to a very low value, and > > >>>> cause a > > >>>> > > > frequent > > >>>> > > > > > > > > >> rolling of > > >>>> > > > > > > > > >> > > > active > > >>>> > > > > > > > > >> > > > > > > segments. > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > Hi Xiongqi, > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > I agree that this is an existing > problem > > >>>> with > > >>>> > > > > > segment.ms. > > >>>> > > > > > > > > >> However, > > >>>> > > > > > > > > >> > > > that > > >>>> > > > > > > > > >> > > > > > doesn't mean that we shouldn't fix it. > As > > >>>> you > > >>>> > noted, > > >>>> > > > > > there > > >>>> > > > > > > > > will > > >>>> > > > > > > > > >> be > > >>>> > > > > > > > > >> > > more > > >>>> > > > > > > > > >> > > > > > interest in these topic-level retention > > >>>> > settings as > > >>>> > > > a > > >>>> > > > > > > result > > >>>> > > > > > > > > of > > >>>> > > > > > > > > >> > GDPR. > > >>>> > > > > > > > > >> > > > It > > >>>> > > > > > > > > >> > > > > > seems likely that pre-existing problems > > >>>> will > > >>>> > cause > > >>>> > > > more > > >>>> > > > > > > > > trouble. > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > The fix seems relatively > straightforward > > >>>> here -- > > >>>> > > > add a > > >>>> > > > > > > > > >> broker-level > > >>>> > > > > > > > > >> > > > > > minimum segment.ms that overrides > > >>>> per-topic > > >>>> > > > minimums. > > >>>> > > > > > We > > >>>> > > > > > > > can > > >>>> > > > > > > > > >> also > > >>>> > > > > > > > > >> > > fail > > >>>> > > > > > > > > >> > > > > > with a helpful error message when > someone > > >>>> > attempts > > >>>> > > > to > > >>>> > > > > > set > > >>>> > > > > > > an > > >>>> > > > > > > > > >> > invalid > > >>>> > > > > > > > > >> > > > > > configuration. > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > > In my option, the minimum of " > > >>>> > > > max.compaction.lag.ms" > > >>>> > > > > > > > should > > >>>> > > > > > > > > >> be > > >>>> > > > > > > > > >> > > > > > > based on the minimum of "segment.ms > ". > > >>>> Since > > >>>> > > > today the > > >>>> > > > > > > > > >> minimum of > > >>>> > > > > > > > > >> > > > > > segment.ms > > >>>> > > > > > > > > >> > > > > > > is 1, "max.compaction.lag.ms" also > > >>>> starts > > >>>> > with > > >>>> > > > 1. "0" > > >>>> > > > > > > > means > > >>>> > > > > > > > > >> > > > disable. I > > >>>> > > > > > > > > >> > > > > > > can use -1 as disable, but it is hard > > to > > >>>> > define > > >>>> > > > the > > >>>> > > > > > > > meaning > > >>>> > > > > > > > > >> of 0 > > >>>> > > > > > > > > >> > > > because > > >>>> > > > > > > > > >> > > > > > we > > >>>> > > > > > > > > >> > > > > > > cannot just roll the active segment > > >>>> > immediately. > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > That's a fair point. We should make 0 = > > >>>> > disable, to > > >>>> > > > be > > >>>> > > > > > > > > >> consistent > > >>>> > > > > > > > > >> > > with > > >>>> > > > > > > > > >> > > > the > > >>>> > > > > > > > > >> > > > > > other settings. > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > best, > > >>>> > > > > > > > > >> > > > > > Colin > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > > > > >>>> > > > > > > > > >> > > > > > > > -- Note that an alternative > > >>>> configuration > > >>>> > is to > > >>>> > > > use > > >>>> > > > > > -1 > > >>>> > > > > > > > as > > >>>> > > > > > > > > >> > > > "disabled" > > >>>> > > > > > > > > >> > > > > > and > > >>>> > > > > > > > > >> > > > > > > > 0 > > >>>> > > > > > > > > >> > > > > > > > > as "immediate compaction". > Because > > >>>> > compaction > > >>>> > > > lag > > >>>> > > > > > is > > >>>> > > > > > > > > still > > >>>> > > > > > > > > >> > > > determined > > >>>> > > > > > > > > >> > > > > > > > > based on min.compaction.lag and > how > > >>>> long > > >>>> > to > > >>>> > > > roll > > >>>> > > > > > an > > >>>> > > > > > > > > active > > >>>> > > > > > > > > >> > > > segment, > > >>>> > > > > > > > > >> > > > > > > > the > > >>>> > > > > > > > > >> > > > > > > > > actual lag for compaction is > > >>>> undetermined > > >>>> > if > > >>>> > > > we > > >>>> > > > > > use > > >>>> > > > > > > > "0". > > >>>> > > > > > > > > >> On > > >>>> > > > > > > > > >> > the > > >>>> > > > > > > > > >> > > > other > > >>>> > > > > > > > > >> > > > > > > > > hand, we can already set > > >>>> > > > > > "min.cleanable.dirty.ratio" > > >>>> > > > > > > > to > > >>>> > > > > > > > > >> > achieve > > >>>> > > > > > > > > >> > > > the > > >>>> > > > > > > > > >> > > > > > > > same > > >>>> > > > > > > > > >> > > > > > > > > goal. So here we choose "0" as > > >>>> "disabled". > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > I would prefer -1 to be the invalid > > >>>> setting. > > >>>> > > > > > Treating > > >>>> > > > > > > 0 > > >>>> > > > > > > > > >> > > differently > > >>>> > > > > > > > > >> > > > > > than > > >>>> > > > > > > > > >> > > > > > > > 1 seems strange to me. > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > =====> see my previous comment, I > am > > >>>> not > > >>>> > > > strongly > > >>>> > > > > > > > against, > > >>>> > > > > > > > > >> but > > >>>> > > > > > > > > >> > 0 > > >>>> > > > > > > > > >> > > is > > >>>> > > > > > > > > >> > > > > > not a > > >>>> > > > > > > > > >> > > > > > > valid configuration in my option. So > I > > >>>> use > > >>>> > "0" as > > >>>> > > > > > > disabled > > >>>> > > > > > > > > >> state. > > >>>> > > > > > > > > >> > > > > > > > > >>>> > > > > > > > > >> > > > > > > best, > > >>>> > > > > > > > > >> > > > > > > > Colin > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > On Tue, Sep 4, 2018, at 15:04, > > xiongqi > > >>>> wu > > >>>> > wrote: > > >>>> > > > > > > > > >> > > > > > > > > Let's VOTE for this KIP. > > >>>> > > > > > > > > >> > > > > > > > > KIP: > > >>>> > > > > > > > > >> > > > > > > > > > > >>>> > > > > > > > > > > >>>> 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>> > > >>>> > > > > > > > < > > >>>> 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>>> > > >>>> > > > > > > > > >> < > > >>>> > 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>> > > >>>> > > > > > > > < > > >>>> 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>>>> > > >>>> > > > > > > > > >> > > < > > >>>> > > > 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>> > > >>>> > > > > > > > < > > >>>> 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>>> > > >>>> > > > > > > > > >> < > > >>>> > 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>> > > >>>> > > > > > > > < > > >>>> 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>>>>> > > >>>> > > > > > > > > >> > > > > > < > > >>>> > > > > > > > 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>> > > >>>> > > > > > > > < > > >>>> 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>>> > > >>>> > > > > > > > > >> < > > >>>> > 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>> > > >>>> > > > > > > > < > > >>>> 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>>>> > > >>>> > > > > > > > > >> > > < > > >>>> > > > 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>> > > >>>> > > > > > > > < > > >>>> 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>>> > > >>>> > > > > > > > > >> < > > >>>> > 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>> > > >>>> > > > > > > > < > > >>>> 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>>>>>> > > >>>> > > > > > > > > >> > > > > > > > > > > %3A+Time-based+log+compaction+policy > > >>>> > > > > > > > > >> > > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > > Implementation: > > >>>> > > > > > > > > >> > > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > > > > >>>> https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>> > > >>>> > > > > > > > > >> <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>>> > > >>>> > > > > > > > > >> > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>> > > >>>> > > > > > > > > >> <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>>>> > > >>>> > > > > > > > > >> > > > > > < > > https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>> > > >>>> > > > > > > > > >> <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>>> > > >>>> > > > > > > > > >> > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>> > > >>>> > > > > > > > > >> <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>> > > >>>> > > > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611> > > >>>> > > > > > <https://github.com/apache/kafka/pull/5611 > > >>>> > <https://github.com/apache/kafka/pull/5611>>>>>> > > >>>> > > > > > > > > >> > > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > > Xiongqi (Wesley) Wu > > >>>> > > > > > > > > >> > > > > > > > > > >>>> > > > > > > > > >> > > > > > > > >>>> > > > > > > > > >> > > > > > >>>> > > > > > > > > >> > > > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > -- > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > Brett Rann > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > Senior DevOps Engineer > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > Zendesk International Ltd > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > 395 Collins Street, Melbourne VIC 3000 > Australia > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > Mobile: +61 (0) 418 826 017 > > >>>> > > > > > > > > >> > > > >>>> > > > > > > > > >> > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > -- > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > Brett Rann > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > Senior DevOps Engineer > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > Zendesk International Ltd > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > 395 Collins Street, Melbourne VIC 3000 Australia > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > Mobile: +61 (0) 418 826 017 > > >>>> > > > > > > > > > > > >>>> > > > > > > > > > > >>>> > > > > > > > > > > >>>> > > > > > > > > -- > > >>>> > > > > > > > > > > >>>> > > > > > > > > Brett Rann > > >>>> > > > > > > > > > > >>>> > > > > > > > > Senior DevOps Engineer > > >>>> > > > > > > > > > > >>>> > > > > > > > > > > >>>> > > > > > > > > Zendesk International Ltd > > >>>> > > > > > > > > > > >>>> > > > > > > > > 395 Collins Street, Melbourne VIC 3000 Australia > > >>>> > > > > > > > > > > >>>> > > > > > > > > Mobile: +61 (0) 418 826 017 > > >>>> > > > > > > > > > > >>>> > > > > > > > > > >>>> > > > > > > > > >>>> > > > > > > > >>>> > > > > > >>>> > > > >>>> > > >>> > > >
