hi all, > JR3. The KIP exposes the group/partition creation time to the client. I am > not sure if there are other use cases for those timestamps. An alternative > is to avoid exposing those timestamps to the client. The group coordinator > will categorize the partitions using those timestamps and include the > categorization in the assigned partitions in GroupHeartbeatResponse.
It inspires me to think about mirror clusters. What if the mirror group is created 'after' the expanded partitions? In this scenario, the new configuration 'max.age.ms' could handle it if users are aware of the migration and set a suitable time interval. Of course, this would require both creation times to be exposed to clients. Best, Chia-Ping On 2026/06/24 20:46:16 Jun Rao via dev wrote: > Hi, Jiunn-Yang, > > Thanks for the updated KIP. > > JR2. Share consumer (KIP-932) states: "If the number of partitions is > increased for a topic with a subscription in a share group, the SPSO for > the newly created share-partitions is initialized to 0 ". However, this > part has not been implemented yet. Currently, all partitions without offset > follows the strategy given by share.auto.offset.reset. So, we have an > opportunity to see if it's better to align this KIP's changes with the > share consumer. > JR2.1 The first part is whether customizing the offset for new partitions > to something other than 0 is useful in the share consumer. It seems that > the motivation in this KIP applies to share consumer too. > JR2.2 The second part is how new partitions are detected. The mechanism > introduced in this KIP seems quite effective. A group coordinator could > pick up newly created partitions for an existing topic or newly created > topics matching the regex. Those partitions are categorized as new > partitions and will follow the strategy given by > auto.offset.reset.new.partitions. > This makes sense since those partitions typically don't have a large > backlog. A consumer could also additionally subscribe to an existing topic > in an existing group. Those partitions will be categorized as existing > partitions. This also makes sense since those partitions could have a large > backlog and it is better to follow the strategy given by auto.offset.reset. It > will be useful to think through whether the logic for categorizing new > partitions should also be reused in the share consumer. > > JR3. The KIP exposes the group/partition creation time to the client. I am > not sure if there are other use cases for those timestamps. An alternative > is to avoid exposing those timestamps to the client. The group coordinator > will categorize the partitions using those timestamps and include the > categorization in the assigned partitions in GroupHeartbeatResponse. > > JR4. It would be useful to support this feature on existing groups as well. > For example, any partition without a creation timestamp can always be > categorized as an existing partition. > > Jun > > On Wed, Jun 24, 2026 at 6:12 AM 黃竣陽 <[email protected]> wrote: > > > Hello Andrew, > > > > Thanks for your feedback, > > >> I've just been re-reading this KIP to ensure that share group support is > > >> not needed. I've discovered that we made a mistake implementing KIP-932 > > in > > >> this area, so we'll rectify that and check whether it's really tight > > enough > > >> not to require KIP-1327. > > > > Could you walk us through the specific area where the mistake was found? > > That would > > help us assess whether it naturally fits within the scope of KIP-1327 or > > should be addressed > > separately. > > > > AS1 I have updated the KIP > > > > Best Regards, > > Jiunn-Yang > > > > > Chia-Ping Tsai <[email protected]> 於 2026年6月24日 晚上8:49 寫道： > > > > > > hi Andrew > > > > > >> I've discovered that we made a mistake implementing KIP-932 in this > > area, > > > so we'll rectify that and check whether it's really tight enough not to > > > require KIP-1327. > > > > > > Would you mind sharing more details about that? If it's not anything > > close > > > to NP-hard, we could definitely look into covering it within KIP-1327 > > > > > > Best, > > > Chia-Ping > > > > > > > > > Andrew Schofield <[email protected]> 於 2026年6月24日週三 下午7:49寫道： > > > > > >> Hi Jiunn-Yang, > > >> I've just been re-reading this KIP to ensure that share group support is > > >> not needed. I've discovered that we made a mistake implementing KIP-932 > > in > > >> this area, so we'll rectify that and check whether it's really tight > > enough > > >> not to require KIP-1327. > > >> > > >> One trivial comments for consistency. > > >> > > >> AS1: In kafka-consumer-groups.sh, unknown column data is represented by > > >> "-", not "N/A". In kafka-topics.sh, we do use "N/A". > > >> > > >> Thanks, > > >> Andrew > > >> > > >> On 2026/06/23 23:23:38 黃竣陽 wrote: > > >>> Hi all, > > >>> > > >>> Manually bumping this thread. > > >>> > > >>> Best Regards, > > >>> Jiunn-Yang > > >>> > > >>>> 黃竣陽 <[email protected]> 於 2026年6月17日 晚上9:17 寫道： > > >>>> > > >>>> Hello chia, > > >>>> > > >>>> Thanks for the feedback, I have updated the KIP. > > >>>> > > >>>> Best Regards, > > >>>> Jiunn-Yang > > >>>> > > >>>>> Chia-Ping Tsai <[email protected]> 於 2026年6月17日 凌晨12:47 寫道： > > >>>>> > > >>>>> hi Jiunn-Yang > > >>>>> > > >>>>>> When the config is set on a cluster that has not yet been > > >> upgraded... classification cannot occur... the consumer falls back to > > the > > >> base auto.offset.reset for the affected partitions. No exception is > > thrown, > > >> and no operational disruption results. > > >>>>> > > >>>>> Existing group can't take advantage of this excellent new > > >> configuration. Allowing users to modify the group creation time might be > > >> overkill. Instead, we could print a useful warning message to guide > > users. > > >> For example, we can suggest that they re-create the group with their > > >> existing committed offsets > > >>>>> > > >>>>>> Protocol changes > > >>>>> > > >>>>> Would you mind listing those RPC changes in a table format? > > >>>>> > > >>>>>> The full interaction matrix between the base policy and the > > >> new-partition policy is: > > >>>>> > > >>>>> Please add a filed to describe the target scenario when using these > > >> policies > > >>>>> > > >>>>> Best, > > >>>>> Chia-Ping > > >>>>> > > >>>>> > > >>>>> On 2026/06/16 16:14:49 黃竣陽 wrote: > > >>>>>> Hello Jun, chia, > > >>>>>> > > >>>>>> Thanks for the feedback, I have updated the KIP for the new > > >>>>>> approach, PTAL > > >>>>>> > > >>>>>> Best Regards, > > >>>>>> Jiunn-Yang > > >>>>>> > > >>>>>>> Chia-Ping Tsai <[email protected]> 於 2026年6月16日 上午8:23 寫道： > > >>>>>>> > > >>>>>>> hi Jun > > >>>>>>> > > >>>>>>> Yes, your approach is great. I think the combination of latest (for > > >> existing partitions) and by_duration (for new partitions) can address > > 99% > > >> of the complaints I have heard regarding this issue. > > >>>>>>> > > >>>>>>> Also, leveraging the group creation time here opens the door to > > >> implementing a new policy based on timestamp seek in the future, should > > the > > >> community want to pursue that. > > >>>>>>> > > >>>>>>> Thanks for your patience and constructive feedback. We will update > > >> the KIP accordingly. > > >>>>>>> > > >>>>>>> Best, Chia-Ping > > >>>>>>> > > >>>>>>>> Jun Rao via dev <[email protected]> 於 2026年6月16日 清晨5:11 寫道： > > >>>>>>>> > > >>>>>>>> Hi, Chia-Ping, > > >>>>>>>> > > >>>>>>>> Thanks for the reply. > > >>>>>>>> > > >>>>>>>> I agree that it's probably useful to allow a user to configure a > > >> different > > >>>>>>>> offset policy for existing partitions vs new partitions. However, > > >> using > > >>>>>>>> group creation time to capture that seems more intuitive. Here is > > >> another > > >>>>>>>> proposal: remove auto.offset.reset.max.age.ms and categorize new > > >> partitions > > >>>>>>>> based on group creation time. Introduce > > >>>>>>>> a new config auto.offset.reset.new.partitions whose values can be > > >> earliest, > > >>>>>>>> latest and by_duration, the same as auto.offset.reset. Users can > > >> set > > >>>>>>>> `auto.offset.reset.new.partitions` to `earliest` if they want to > > >> guarantee > > >>>>>>>> no data loss on new partitions. They can also use by_duration to > > >> set an > > >>>>>>>> upper bound on the backlog replayed, which can be different from > > >> that of > > >>>>>>>> the existing partitions. This will address your concern about too > > >> much > > >>>>>>>> backlog being replayed when the offsets are lost. What do you > > >> think? > > >>>>>>>> > > >>>>>>>> Jun > > >>>>>>>> > > >>>>>>>> > > >>>>>>>>> On Mon, Jun 15, 2026 at 10:39 AM Chia-Ping Tsai < > > >> [email protected]> wrote: > > >>>>>>>>> > > >>>>>>>>> hi Jun > > >>>>>>>>> > > >>>>>>>>> The most important part of this story is how users should expect > > >> the data > > >>>>>>>>> they can see when using the latest or by_duration policy with > > >> expanded > > >>>>>>>>> partitions. > > >>>>>>>>> > > >>>>>>>>> Yes, the by_duration policy can minimize data loss, but it is > > >>>>>>>>> non-deterministic, which means users will either read too many > > >> historical > > >>>>>>>>> records from existing partitions or lose some records from > > >> expanded > > >>>>>>>>> partitions. > > >>>>>>>>> > > >>>>>>>>> Also, I agree that auto.offset.reset.max.age.ms > > >>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.max.age.ms__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpwnwknH$ > > >>> > > >>>>>>>>> is a bit hard to understand, and that is why I preferred having a > > >> whole new > > >>>>>>>>> policy based entirely on group creation time (KIP-1282) > > >>>>>>>>> > > >>>>>>>>> Best, > > >>>>>>>>> Chia-Ping > > >>>>>>>>> > > >>>>>>>>> Jun Rao via dev <[email protected]> 於 2026年6月16日週二 上午1:08寫道： > > >>>>>>>>> > > >>>>>>>>>> Hi, Chia-Ping and Jiunn-Yang, > > >>>>>>>>>> > > >>>>>>>>>> Thanks for the reply. I am still trying to understand the value > > >> of the new > > >>>>>>>>>> configs with the KIP. > > >>>>>>>>>> > > >>>>>>>>>> The motivation of the KIP is that a user doesn't want to miss > > >> the data if > > >>>>>>>>>> the backlog is small. The backlog of the existing partition is > > >> easy to > > >>>>>>>>>> understand because it relates to retention time. The backlog for > > >> the new > > >>>>>>>>>> partition is a bit subtle to understand since it depends on the > > >> metadata > > >>>>>>>>>> refresh delay. To set auto.offset.reset.max.age.ms > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.max.age.ms__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpwnwknH$ > > >>> , > > >>>>>>>>>> the user needs to > > >>>>>>>>>> understand the metadata refresh delay on the consumer side and > > >> use it to > > >>>>>>>>>> set the config. > > >>>>>>>>>> > > >>>>>>>>>> Now, let's consider the alternative: setting the same value for > > >> the > > >>>>>>>>>> existing by_duration policy. The KIP lists three issues with > > this > > >>>>>>>>>> approach. > > >>>>>>>>>> 1. It computes the seek target client-side as now() - duration, > > >> which > > >>>>>>>>>> introduces clock skew across consumers and forces operators to > > >> choose > > >>>>>>>>>> overly large durations, causing unnecessary reprocessing. > > >>>>>>>>>> 2. The target timestamp is recomputed on each retry, so failed > > >>>>>>>>>> ListOffsetsRequest retries can shift the target forward and > > >> potentially > > >>>>>>>>>> miss records produced between attempts. > > >>>>>>>>>> 3. It applies uniformly to all partitions without committed > > >> offsets, and > > >>>>>>>>>> cannot distinguish newly expanded partitions from long-existing > > >> partitions > > >>>>>>>>>> newly assigned to the group, leading to unnecessary replay. > > >>>>>>>>>> > > >>>>>>>>>> Issues 1 and 2 are uncommon and can be mitigated by adding a bit > > >> buffer to > > >>>>>>>>>> the metadata refresh delay. We could also consider improving the > > >>>>>>>>>> implementation. For issue 3, the metadata refresh delay is > > >> typically low > > >>>>>>>>>> (in the order of minutes with the classic consumer and tens of > > >> seconds > > >>>>>>>>>> with > > >>>>>>>>>> the new consumer). If a user is ok with reading that much > > >> backlog for new > > >>>>>>>>>> partitions, it seems they will be ok doing the same for existing > > >>>>>>>>>> partitions. > > >>>>>>>>>> > > >>>>>>>>>> So, instead of introducing a new config, could we just reuse the > > >> existing > > >>>>>>>>>> config with better documentation and/or implementation? > > >>>>>>>>>> > > >>>>>>>>>> Jun > > >>>>>>>>>> > > >>>>>>>>>> > > >>>>>>>>>>> On Sat, Jun 13, 2026 at 12:19 AM 黃竣陽 <[email protected]> > > >> wrote: > > >>>>>>>>>> > > >>>>>>>>>>> Hello Jun, > > >>>>>>>>>>> > > >>>>>>>>>>> You're right that group creation time is the more intuitive > > >> answer at > > >>>>>>>>>>> first glance, > > >>>>>>>>>>> the KIP's own motivation talks about partitions that "predate > > >> the group" > > >>>>>>>>>>> vs partitions > > >>>>>>>>>>> "created during group runtime," which directly points to a > > >>>>>>>>>> group-lifecycle > > >>>>>>>>>>> classifier. > > >>>>>>>>>>> I'd like to walk through why we landed on partition age, and > > the > > >>>>>>>>>>> trade-offs we considered. > > >>>>>>>>>>> > > >>>>>>>>>>> We evaluated three candidate signals: > > >>>>>>>>>>> > > >>>>>>>>>>> 1. `by_duration:5secs` > > >>>>>>>>>>> > > >>>>>>>>>>> This covers the metadata blindness window, but has issues the > > >> KIP > > >>>>>>>>>>> currently documents > > >>>>>>>>>>> under "Why not use `by_duration`?": > > >>>>>>>>>>> > > >>>>>>>>>>> - Client-side `now() - duration` introduces clock skew across > > >> consumers. > > >>>>>>>>>>> - `ListOffsets` retries shift the target forward, potentially > > >> missing > > >>>>>>>>>>> records produced between > > >>>>>>>>>>> attempts. > > >>>>>>>>>>> - It applies uniformly to all partitions without committed > > >> offsets, > > >>>>>>>>>>> including pre-existing partitions > > >>>>>>>>>>> newly assigned to the group, causing unnecessary replay. > > >>>>>>>>>>> > > >>>>>>>>>>> 2. Group creation time as classifier > > >>>>>>>>>>> > > >>>>>>>>>>> This works cleanly when the consumer is actively running. Our > > >> concern > > >>>>>>>>>>> is the idle / late-rejoin case: > > >>>>>>>>>>> > > >>>>>>>>>>> T=0: Group created. > > >>>>>>>>>>> T=1..T=100: Consumer idle (down, disconnected, etc.). > > >>>>>>>>>>> T=50: Partition added during the idle window. > > >>>>>>>>>>> T=100: Consumer resumes. > > >>>>>>>>>>> > > >>>>>>>>>>> Under group creation time, the new partition is classified as > > >> new > > >>>>>>>>>>> (`50 > 0`) and reset to `earliest`, replaying everything from > > >> T=50. > > >>>>>>>>>>> But during `[T=1, T=100]`, base partitions also accumulated > > >> data that > > >>>>>>>>>>> the consumer accepts as lost — that is precisely the contract > > of > > >>>>>>>>>>> `auto.offset.reset=latest`. There is no principled reason to > > >> treat > > >>>>>>>>>>> the new partition differently; both contain backlog accumulated > > >> during > > >>>>>>>>>>> the same idle window. > > >>>>>>>>>>> > > >>>>>>>>>>> This aligns with the "backlog is backlog” principle you raised > > >> in > > >>>>>>>>>>> the KIP-1282 thread: a `latest` user has tolerated some backlog > > >> on > > >>>>>>>>>>> every other partition during the same idle period; forcing > > >> 0-backlog > > >>>>>>>>>>> tolerance only on new partitions would be inconsistent with > > that > > >>>>>>>>>>> tolerance. > > >>>>>>>>>>> > > >>>>>>>>>>> 3. Partition age vs threshold > > >>>>>>>>>>> > > >>>>>>>>>>> Partition age corresponds to the actual silent data loss > > window, > > >>>>>>>>>>> the gap between partition creation and the consumer’s metadata > > >>>>>>>>>>> refresh. Within this window, data loss is genuinely silent: the > > >>>>>>>>>>> consumer had no opportunity to know about the partition. > > >> Outside this > > >>>>>>>>>>> window, missing data reflects either: > > >>>>>>>>>>> > > >>>>>>>>>>> - (a) the user’s tolerated cost of running with idle consumers, > > >> or > > >>>>>>>>>>> - (b) an operational issue to surface via monitoring, not via > > >> reset > > >>>>>>>>>> policy. > > >>>>>>>>>>> > > >>>>>>>>>>> We did not choose partition age because it is more elegant than > > >> group > > >>>>>>>>>>> creation time — we chose it because its failure mode (requires > > a > > >>>>>>>>>>> threshold) is > > >>>>>>>>>>> less invasive than the failure mode of group creation time > > >> (overrides > > >>>>>>>>>>> user-stated > > >>>>>>>>>>> `latest` intent during idle periods). > > >>>>>>>>>>> > > >>>>>>>>>>> Best Regards, > > >>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>> > > >>>>>>>>>>>> Chia-Ping Tsai <[email protected]> 於 2026年6月13日 上午11:52 寫道： > > >>>>>>>>>>>> > > >>>>>>>>>>>> Hi Jun, > > >>>>>>>>>>>> > > >>>>>>>>>>>> Relying on both creation times will create an inconsistent > > >> scenario. A > > >>>>>>>>>>>> consumer that lost all offsets due to a long sleep will seek > > >> to the > > >>>>>>>>>>>> beginning for the partitions created later than the group. > > >>>>>>>>>>>> > > >>>>>>>>>>>> That is why we initially proposed KIP-1282 to fix the > > >> inconsistency > > >>>>>>>>>>> using a > > >>>>>>>>>>>> whole new policy. Since KIP-1282 couldn't reach a consensus, > > >> KIP-1327 > > >>>>>>>>>>> goes > > >>>>>>>>>>>> back to using flexible configurations to prevent users from > > >> falling > > >>>>>>>>>> into > > >>>>>>>>>>>> that pitfall. > > >>>>>>>>>>>> > > >>>>>>>>>>>> Best, Chia-Ping > > >>>>>>>>>>>> > > >>>>>>>>>>>> Jun Rao via dev <[email protected]> 於 2026年6月13日週六 > > >> 上午6:49寫道： > > >>>>>>>>>>>> > > >>>>>>>>>>>>> Hi, Jiunn-Yang, > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Thanks for the reply and sorry for the late reply. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> JR1. The design of auto.offset.reset.max.age.ms > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.max.age.ms__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpwnwknH$ > > >>> > > >>>>>>>>>> still feels weird to > > >>>>>>>>>>> me. > > >>>>>>>>>>>>> It > > >>>>>>>>>>>>> categorizes partitions as new or existing based on the > > >> partition > > >>>>>>>>>>> creation > > >>>>>>>>>>>>> time. Intuitively, the categorization should be based on the > > >> group > > >>>>>>>>>>> creation > > >>>>>>>>>>>>> time: all partitions existing when the group is created are > > >> existing > > >>>>>>>>>> and > > >>>>>>>>>>>>> all partitions created after the group creation are new > > >> partitions. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Jun > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> On Tue, Jun 9, 2026 at 8:51 AM 黃竣陽 <[email protected]> > > >> wrote: > > >>>>>>>>>>>>> > > >>>>>>>>>>>>>> Hi all, > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> Manually bumping this thread. If there is no further > > >>>>>>>>>>>>>> discussion, I will close the vote. > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> 黃竣陽 <[email protected]> 於 2026年6月1日 晚上7:16 寫道： > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> Hello Jian, > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> Thanks for your feedback, > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> Agreed, partition expansion is a common operational task, > > >> not an > > >>>>>>>>>> edge > > >>>>>>>>>>>>>>> case. I've updated the Motivation section accordingly. > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> jian fu <[email protected]> 於 2026年6月1日 下午5:49 寫道： > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> Hi Jiunn-Yang: > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> Thanks for the KIP. I think it would be useful to clarify > > >> that > > >>>>>>>>>> this > > >>>>>>>>>>>>> is a > > >>>>>>>>>>>>>>>> common scenario rather than an edge case, which further > > >>>>>>>>>> demonstrates > > >>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>> need for this optimization. For example: > > >>>>>>>>>>>>>>>> A partition expansion is a common operational task in > > >> Kafka: To > > >>>>>>>>>>>>> balance > > >>>>>>>>>>>>>>>> resource utilization and cost, topics are typically > > >> created with a > > >>>>>>>>>>>>>> moderate > > >>>>>>>>>>>>>>>> default partition count. However, as traffic grows over > > >> time, it > > >>>>>>>>>> is > > >>>>>>>>>>>>>> often > > >>>>>>>>>>>>>>>> necessary to increase the number of partitions to > > >> accommodate the > > >>>>>>>>>>>>> higher > > >>>>>>>>>>>>>>>> workload. > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> Regards > > >>>>>>>>>>>>>>>> Jian > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> 黃竣陽 <[email protected]> 于2026年5月30日周六 22:31写道： > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>> Hello chia, > > >>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>> Thanks for the comments, I have updated the KIP! > > >>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> Chia-Ping Tsai <[email protected]> 於 2026年5月30日 晚上8:29 > > >> 寫道： > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> Hi Jiunn-Yang, > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> Would you mind removing the terms "hot" and "cold" when > > >>>>>>>>>> describing > > >>>>>>>>>>>>>>>>>> partitions in the KIP? I understand you are using them > > to > > >>>>>>>>>> describe > > >>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>> "freshness" or the users' need for the records, but > > >> applying > > >>>>>>>>>> these > > >>>>>>>>>>>>>> terms > > >>>>>>>>>>>>>>>>> to > > >>>>>>>>>>>>>>>>>> the partition itself feels a bit unnatural. > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> After all, in this scenario, users don't really care > > >> whether a > > >>>>>>>>>>>>>> partition > > >>>>>>>>>>>>>>>>> is > > >>>>>>>>>>>>>>>>>> newly expanded or not. Their only expectation is that > > >> they won't > > >>>>>>>>>>>>>> silently > > >>>>>>>>>>>>>>>>>> lose any live records produced to the topic during their > > >> active > > >>>>>>>>>>>>>>>>> consumption. > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> Best, Chia-Ping > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>> 黃竣陽 <[email protected]> 於 2026年5月30日週六 下午12:30寫道： > > >>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>> Hello Jun, > > >>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>> Thanks for the feedback, I have updated the KIP > > >> motivation > > >>>>>>>>>>> section. > > >>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> Jun Rao via dev <[email protected]> 於 2026年5月30日 > > >> 凌晨1:12 > > >>>>>>>>>> 寫道： > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> Hi, Jiunn-Yang, > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> Thanks for the reply. I think we need a stronger > > >> motivation > > >>>>>>>>>> for > > >>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>> KIP. > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> The KIP says "The core insight is that not all > > >> partitions > > >>>>>>>>>> without > > >>>>>>>>>>>>> a > > >>>>>>>>>>>>>>>>>>>> committed offset are the same. A newly expanded > > >> partition > > >>>>>>>>>> (hot) > > >>>>>>>>>>> is > > >>>>>>>>>>>>>>>>>>>> fundamentally different from a partition the consumer > > >> has > > >>>>>>>>>> never > > >>>>>>>>>>>>> seen > > >>>>>>>>>>>>>>>>>>>> because it predates the group (cold)." Why is the hot > > >>>>>>>>>> partition > > >>>>>>>>>>>>>>>>>>>> fundamentally different from the cold? > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> The KIP says "The existing by_duration policy is also > > >>>>>>>>>>> insufficient > > >>>>>>>>>>>>>>>>>>> because: > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> - The calculated seek time (now() - duration) varies > > >> across > > >>>>>>>>>> nodes > > >>>>>>>>>>>>>> due > > >>>>>>>>>>>>>>>>>>> to > > >>>>>>>>>>>>>>>>>>>> clock skew. To be safe, users must set an overly large > > >>>>>>>>>> duration, > > >>>>>>>>>>>>>>>>>>> causing > > >>>>>>>>>>>>>>>>>>>> unnecessary reprocessing. > > >>>>>>>>>>>>>>>>>>>> - On network errors, the client recalculates the seek > > >> time on > > >>>>>>>>>>>>> retry, > > >>>>>>>>>>>>>>>>>>>> shifting the target timestamp forward and risking data > > >> loss." > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> However, both of these situations are rare. If these > > >> issues > > >>>>>>>>>>>>> persist, > > >>>>>>>>>>>>>>>>> more > > >>>>>>>>>>>>>>>>>>>> severe problems likely exist elsewhere. Rare > > >> situations don't > > >>>>>>>>>>>>> need a > > >>>>>>>>>>>>>>>>>>> common > > >>>>>>>>>>>>>>>>>>>> solution. If users care about those rare situations, > > >> they can > > >>>>>>>>>>>>>> implement > > >>>>>>>>>>>>>>>>>>>> customized logic using > > >>>>>>>>>>>>>>>>> ConsumerRebalanceListener.onPartitionsAssigned(). > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> Jun > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>> On Sun, May 17, 2026 at 6:50 AM 黃竣陽 < > > >> [email protected]> > > >>>>>>>>>> wrote: > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> Hello chia, > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> Thanks for the feedback, > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> If the creation time exists, the returned value > > >> should > > >>>>>>>>>> always > > >>>>>>>>>>> be > > >>>>>>>>>>>>>>>>>>> greater > > >>>>>>>>>>>>>>>>>>>>> than or equal to zero, right? > > >>>>>>>>>>>>>>>>>>>>> I have explicitly mentioned this in the KIP. > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> New Old (MetadataResponse v0–13) positive > > >> any > > >>>>>>>>>>>>>> field > > >>>>>>>>>>>>>>>>>>>>> absent UnsupportedVersionException > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> The earliest point at which we can detect the version > > >>>>>>>>>> mismatch > > >>>>>>>>>>> is > > >>>>>>>>>>>>>>>>> during > > >>>>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>> first metadata fetch after assignment, which occurs > > >> inside > > >>>>>>>>>>>>> poll(). > > >>>>>>>>>>>>>>>>>>>>> Therefore, the > > >>>>>>>>>>>>>>>>>>>>> user would encounter an UnsupportedVersionException > > >> from > > >>>>>>>>>> poll(). > > >>>>>>>>>>>>>> I’ll > > >>>>>>>>>>>>>>>>>>>>> clarify this in the KIP. > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> Chia-Ping Tsai <[email protected]> 於 2026年5月17日 > > >> 下午4:50 > > >>>>>>>>>> 寫道： > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> hi Jiunn > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> PartitionAgeMs (int64, default -1): The age of this > > >>>>>>>>>> partition > > >>>>>>>>>>>>> in > > >>>>>>>>>>>>>>>>>>>>> milliseconds, computed server-side by the broker as > > >>>>>>>>>>>>>>>>> broker_current_time > > >>>>>>>>>>>>>>>>>>> - > > >>>>>>>>>>>>>>>>>>>>> partition_creation_time. Returns -1 if the broker > > >> does not > > >>>>>>>>>>>>> support > > >>>>>>>>>>>>>>>>> this > > >>>>>>>>>>>>>>>>>>>>> feature or the partition creation time is unknown. > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> If the creation time exists, the returned value > > >> should > > >>>>>>>>>> always > > >>>>>>>>>>> be > > >>>>>>>>>>>>>>>>>>> greater > > >>>>>>>>>>>>>>>>>>>>> than or equal to zero, right? > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> New Old (MetadataResponse v0–13) positive > > >> any > > >>>>>>>>>>>>>> field > > >>>>>>>>>>>>>>>>>>>>> absent UnsupportedVersionException > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> Will user encounter UnsupportedVersionException when > > >> calling > > >>>>>>>>>>>>>>>>> `poll()`? > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> Best, > > >>>>>>>>>>>>>>>>>>>>>> Chia-Ping > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>> On 2026/05/16 04:30:49 黃竣陽 wrote: > > >>>>>>>>>>>>>>>>>>>>>>> Hello Jun, chia, > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> I've updated KIP-1327 with a design change based on > > >> the > > >>>>>>>>>>>>>> discussion > > >>>>>>>>>>>>>>>>>>>>>>> feedback. > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> The updated design decouples the new-partition > > reset > > >>>>>>>>>> behavior > > >>>>>>>>>>>>>> from > > >>>>>>>>>>>>>>>>>>>>>>> the base auto.offset.reset policy: > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> - auto.offset.reset.max.age.ms > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.max.age.ms__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpwnwknH$ > > >>> > > >>>>>>>>>> now applies to all > > >>>>>>>>>>>>>> auto.offset.reset > > >>>>>>>>>>>>>>>>>>>>> values > > >>>>>>>>>>>>>>>>>>>>>>> (latest, earliest, by_duration, none). > > >>>>>>>>>>>>>>>>>>>>>>> - For new ("hot") partitions, the consumer resets > > to > > >>>>>>>>>>>>>>>>>>>>> auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> > > >>>>>>>>>> .partitions > > >>>>>>>>>>>>>>>>>>>>>>> config setting > > >>>>>>>>>>>>>>>>>>>>>>> - For existing ("cold") partitions, the base > > >>>>>>>>>> auto.offset.reset > > >>>>>>>>>>>>>>>>> policy > > >>>>>>>>>>>>>>>>>>>>> continues > > >>>>>>>>>>>>>>>>>>>>>>> to apply unchanged. > > >>>>>>>>>>>>>>>>>>>>>>> - The new-partition reset behavior is represented > > >> by a > > >>>>>>>>>>> separate > > >>>>>>>>>>>>>>>>>>>>> internal config > > >>>>>>>>>>>>>>>>>>>>>>> (auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> .partitions, > > >>>>>>>>>> currently fixed to > > >>>>>>>>>>>>> earliest). > > >>>>>>>>>>>>>>>>> This > > >>>>>>>>>>>>>>>>>>>>> decoupled design makes > > >>>>>>>>>>>>>>>>>>>>>>> it straightforward to promote the behavior to a > > >> public > > >>>>>>>>>>>>>> user-facing > > >>>>>>>>>>>>>>>>>>>>> configuration in a future KIP. > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>> Chia-Ping Tsai <[email protected]> 於 2026年5月16日 > > >> 清晨7:46 > > >>>>>>>>>> 寫道： > > >>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>> hi Jun > > >>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>> I see what you mean now. The proposal from me is > > >> listed > > >>>>>>>>>>> below: > > >>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>> 1) Add auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> .partitions > > >>>>>>>>>> with a default value > > >>>>>>>>>>>>> of > > >>>>>>>>>>>>>>>>>>>>> earliest. It fixes the data loss from both > > >> by_duration and > > >>>>>>>>>>>>> latest, > > >>>>>>>>>>>>>> and > > >>>>>>>>>>>>>>>>>>> it > > >>>>>>>>>>>>>>>>>>>>> does not change the logic of > > >> auto.offset.reset=earliest. > > >>>>>>>>>>>>>>>>>>>>>>>> 2) Mark auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> .partitions > > >>>>>>>>>> as an internal > > >>>>>>>>>>>>>>>>>>>>> configuration. auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> > > >>>>>>>>>> .partitions=earliest > > >>>>>>>>>>> already > > >>>>>>>>>>>>>>>>>>>>> addresses the issue, and we can discuss the use cases > > >> of > > >>>>>>>>>> other > > >>>>>>>>>>>>>> values > > >>>>>>>>>>>>>>>>>>> in a > > >>>>>>>>>>>>>>>>>>>>> separate KIP. > > >>>>>>>>>>>>>>>>>>>>>>>> 3) Both configs, auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> .partitions > > >>>>>>>>>> and > > >>>>>>>>>>>>>>>>>>>>> auto.offset.reset.latest.max.age.ms > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.latest.max.age.ms__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfu9JSP4l$ > > >>> , > > >>>>>>>>>> will be applied to all for > > >>>>>>>>>>>>>>>>>>>>> consistency. > > >>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>> WDYT? > > >>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>> On 2026/05/15 20:53:20 Jun Rao via dev wrote: > > >>>>>>>>>>>>>>>>>>>>>>>>> Hi, Chia-Ping, > > >>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>> Thanks for the reply. > > >>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>> 1. In the motivation section, the KIP says "When > > >> a Kafka > > >>>>>>>>>>>>> topic > > >>>>>>>>>>>>>> is > > >>>>>>>>>>>>>>>>>>>>> expanded > > >>>>>>>>>>>>>>>>>>>>>>>>> with new partitions, consumers using the latest > > >> auto > > >>>>>>>>>> offset > > >>>>>>>>>>>>>> reset > > >>>>>>>>>>>>>>>>>>>>> policy > > >>>>>>>>>>>>>>>>>>>>>>>>> will silently miss all records produced to those > > >>>>>>>>>> partitions > > >>>>>>>>>>>>>> before > > >>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>> consumer discovers them.". If a user sets > > >>>>>>>>>>>>>>>>>>>>>>>>> auto.offset.reset=by_duration=1sec, the same > > >> record loss > > >>>>>>>>>>>>> issue > > >>>>>>>>>>>>>>>>> could > > >>>>>>>>>>>>>>>>>>>>> also > > >>>>>>>>>>>>>>>>>>>>>>>>> happen, right? > > >>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>> 2. I was thinking auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> .partitions > > >>>>>>>>>> will > > >>>>>>>>>>> take > > >>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>> same > > >>>>>>>>>>>>>>>>>>>>>>>>> values as auto.offset.reset. So a user could set > > >> it > > >>>>>>>>>>>>>> by_duration if > > >>>>>>>>>>>>>>>>>>>>> needed. > > >>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>> Jun > > >>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>> On Thu, May 14, 2026 at 4:06 PM Chia-Ping Tsai < > > >>>>>>>>>>>>>>>>> [email protected] > > >>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> wrote: > > >>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> hi Jun > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> Thanks for the feedback. I might be missing > > >> something > > >>>>>>>>>>>>>> important > > >>>>>>>>>>>>>>>>>>> from > > >>>>>>>>>>>>>>>>>>>>> your > > >>>>>>>>>>>>>>>>>>>>>>>>>> suggestion, so please bear with me as I try to > > >> clarify > > >>>>>>>>>> with > > >>>>>>>>>>>>> a > > >>>>>>>>>>>>>> few > > >>>>>>>>>>>>>>>>>>>>> questions: > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> 1. Is there a strong use case for extending this > > >> logic > > >>>>>>>>>> to > > >>>>>>>>>>>>>> other > > >>>>>>>>>>>>>>>>>>> reset > > >>>>>>>>>>>>>>>>>>>>>>>>>> policies? Unlike latest, policies like earliest > > >> or > > >>>>>>>>>>>>> by_duration > > >>>>>>>>>>>>>>>>>>> don't > > >>>>>>>>>>>>>>>>>>>>> seem > > >>>>>>>>>>>>>>>>>>>>>>>>>> to suffer from the same silent data loss issue > > >> when a > > >>>>>>>>>>>>>> partition > > >>>>>>>>>>>>>>>>> is > > >>>>>>>>>>>>>>>>>>>>> expanded. > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> 2. What values would we expect users to > > >> configure for > > >>>>>>>>>>>>>>>>>>>>>>>>>> auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> .partitions? > > >>>>>>>>>> If they set it to > > >>>>>>>>>>>>> earliest > > >>>>>>>>>>>>>> or > > >>>>>>>>>>>>>>>>>>>>> latest, > > >>>>>>>>>>>>>>>>>>>>>>>>>> we might run into the exact same edge cases. For > > >>>>>>>>>> example, > > >>>>>>>>>>>>> if a > > >>>>>>>>>>>>>>>>>>>>> consumer is > > >>>>>>>>>>>>>>>>>>>>>>>>>> offline for a while and a new partition is > > >> created > > >>>>>>>>>> during > > >>>>>>>>>>>>> that > > >>>>>>>>>>>>>>>>>>>>> downtime, > > >>>>>>>>>>>>>>>>>>>>>>>>>> the user might actually want to skip to latest > > >> when > > >>>>>>>>>>>>> resuming, > > >>>>>>>>>>>>>>>>>>> rather > > >>>>>>>>>>>>>>>>>>>>> than > > >>>>>>>>>>>>>>>>>>>>>>>>>> reading from earliest just because the partition > > >> is > > >>>>>>>>>>>>>> technically > > >>>>>>>>>>>>>>>>>>>>> "new" to > > >>>>>>>>>>>>>>>>>>>>>>>>>> the group. > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> This is exactly why we opted for introducing a > > >> max.age > > >>>>>>>>>>>>>> threshold. > > >>>>>>>>>>>>>>>>>>> It > > >>>>>>>>>>>>>>>>>>>>> gives > > >>>>>>>>>>>>>>>>>>>>>>>>>> users a time-bound way to define what is > > >> genuinely > > >>>>>>>>>>> "hot/new" > > >>>>>>>>>>>>>> and > > >>>>>>>>>>>>>>>>>>>>> what is > > >>>>>>>>>>>>>>>>>>>>>>>>>> just an old partition they haven't seen yet. > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> Best, > > >>>>>>>>>>>>>>>>>>>>>>>>>> Chia-Ping > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> On 2026/05/14 20:48:09 Jun Rao via dev wrote: > > >>>>>>>>>>>>>>>>>>>>>>>>>>> Hi, Jiunn-Yang, > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>> Thanks for the KIP. > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>> I find auto.offset.reset.latest.max.age a bit > > >> weird. It > > >>>>>>>>>>>>> only > > >>>>>>>>>>>>>>>>>>>>> applies when > > >>>>>>>>>>>>>>>>>>>>>>>>>>> auto.offset.reset is latest. However, it seems > > >> that the > > >>>>>>>>>>>>>>>>> motivation > > >>>>>>>>>>>>>>>>>>>>>>>>>> equally > > >>>>>>>>>>>>>>>>>>>>>>>>>>> applies when auto.offset.reset is set to other > > >> values > > >>>>>>>>>> like > > >>>>>>>>>>>>>>>>>>>>> by_duration. > > >>>>>>>>>>>>>>>>>>>>>>>>>> The > > >>>>>>>>>>>>>>>>>>>>>>>>>>> intention is that we want to have a separate > > >> way to > > >>>>>>>>>>> control > > >>>>>>>>>>>>>>>>> newly > > >>>>>>>>>>>>>>>>>>>>> created > > >>>>>>>>>>>>>>>>>>>>>>>>>>> partitions vs existing partitions when the > > group > > >>>>>>>>>> starts. > > >>>>>>>>>>>>>> Have we > > >>>>>>>>>>>>>>>>>>>>>>>>>> considered > > >>>>>>>>>>>>>>>>>>>>>>>>>>> adding a new config like auto.offset.reset.new > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://auto.offset.reset.new__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkfpDMjdw3$ > > >>> > > >>>>>>>>>>> .partitions? > > >>>>>>>>>>>>>> If > > >>>>>>>>>>>>>>>>>>> this > > >>>>>>>>>>>>>>>>>>>>> new > > >>>>>>>>>>>>>>>>>>>>>>>>>>> config is not set, the offset reset policy > > >> defaults to > > >>>>>>>>>> the > > >>>>>>>>>>>>>>>>> policy > > >>>>>>>>>>>>>>>>>>>>> used > > >>>>>>>>>>>>>>>>>>>>>>>>>> for > > >>>>>>>>>>>>>>>>>>>>>>>>>>> existing partitions. The user could set it > > >> explicitly > > >>>>>>>>>> to > > >>>>>>>>>>>>>>>>> customize > > >>>>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>>> behavior for new partitions. > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>> Jun > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>> On Thu, May 7, 2026 at 5:07 AM 黃竣陽 < > > >> [email protected] > > >>>>>>>>>>> > > >>>>>>>>>>>>>> wrote: > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> Hi all, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> I’d like to manually bump this thread. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> 黃竣陽 <[email protected]> 於 2026年5月1日 晚上10:37 > > >> 寫道： > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> Hello all, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> Thanks for the feedback. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> DJ01/DJ02: > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> MetadataResponse bumps from v13 to v14. The > > >>>>>>>>>>>>>> PartitionMetadata > > >>>>>>>>>>>>>>>>>>>>> struct > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> gains a new > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> field PartitionAgeMs (int64, default -1), > > >> computed > > >>>>>>>>>>>>>> server-side > > >>>>>>>>>>>>>>>>>>> by > > >>>>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> broker as > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> broker_current_time - > > partition_creation_time. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> Also add the consumer heartbeat flow. when > > >>>>>>>>>>>>>> MembershipManager > > >>>>>>>>>>>>>>>>>>>>> detects > > >>>>>>>>>>>>>>>>>>>>>>>>>> a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> newly assigned > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> partition, it explicitly invalidates the > > >> metadata for > > >>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>> affected > > >>>>>>>>>>>>>>>>>>>>>>>>>> topic > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> and forces a fresh MetadataRequest > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> before making the offset reset decision, even > > >> if the > > >>>>>>>>>>>>> topic > > >>>>>>>>>>>>>> ID > > >>>>>>>>>>>>>>>>> is > > >>>>>>>>>>>>>>>>>>>>>>>>>> already > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> in the cache. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> MB0: > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> The consumer learns the broker's maximum > > >> supported > > >>>>>>>>>>>>>>>>>>>>> MetadataResponse > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> version via the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> ApiVersions negotiation at connection time. > > >> If the > > >>>>>>>>>>>>>> negotiated > > >>>>>>>>>>>>>>>>>>>>>>>>>> version is > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> unsupported, the consumer > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> knows the broker does not support > > >> PartitionAgeMs at > > >>>>>>>>>> all > > >>>>>>>>>>>>> and > > >>>>>>>>>>>>>>>>> can > > >>>>>>>>>>>>>>>>>>>>>>>>>> throw an > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> UnsupportedVersionException > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> immediately, rather than silently falling > > >> back to > > >>>>>>>>>> latest > > >>>>>>>>>>>>>> and > > >>>>>>>>>>>>>>>>>>>>> risking > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> data loss without any operator-visible signal. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> MB1/MB2/MB3: > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> I have addressed these changes in the KIP. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Chia-Ping Tsai <[email protected]> 於 > > >> 2026年4月29日 > > >>>>>>>>>>> 下午4:04 > > >>>>>>>>>>>>>> 寫道： > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> hi David > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I agree with the direction of moving the > > >> 'age' > > >>>>>>>>>>>>> resolution > > >>>>>>>>>>>>>>>>> from > > >>>>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> Heartbeat API to the Metadata API to keep the > > >> control > > >>>>>>>>>>>>> plane > > >>>>>>>>>>>>>>>>>>> clean. > > >>>>>>>>>>>>>>>>>>>>> The > > >>>>>>>>>>>>>>>>>>>>>>>>>> main > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> trade-off, as we noted before, is introducing > > >>>>>>>>>>> inter-broker > > >>>>>>>>>>>>>>>>> clock > > >>>>>>>>>>>>>>>>>>>>> skew. > > >>>>>>>>>>>>>>>>>>>>>>>>>> The > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> Group Coordinator approach provided a single > > >> source of > > >>>>>>>>>>>>> truth > > >>>>>>>>>>>>>>>>> for > > >>>>>>>>>>>>>>>>>>>>> time. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> However, realistically, this time skew > > >> should be > > >>>>>>>>>>>>>> negligible. > > >>>>>>>>>>>>>>>>>>>>> Given > > >>>>>>>>>>>>>>>>>>>>>>>>>> that > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> the max.age threshold will likely be > > >> configured in > > >>>>>>>>>>> minutes > > >>>>>>>>>>>>>> or > > >>>>>>>>>>>>>>>>>>>>> hours, a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> typical NTP skew (in milliseconds) between > > >> brokers > > >>>>>>>>>> won't > > >>>>>>>>>>>>>> impact > > >>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> fallback decision. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Best, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Chia-Ping > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> David Jacot via dev <[email protected]> > > >> 於 > > >>>>>>>>>>>>> 2026年4月29日 > > >>>>>>>>>>>>>>>>>>> 下午3:29 > > >>>>>>>>>>>>>>>>>>>>> 寫道： > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Hi all, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Thanks for the KIP! > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Sorry, I haven't really followed the > > >> previous > > >>>>>>>>>>>>>> conversation > > >>>>>>>>>>>>>>>>>>> but I > > >>>>>>>>>>>>>>>>>>>>>>>>>> took a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> quick look at this one. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> DJ01: I don't clearly understand the flow > > >> with the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> ConsumerGroupHeartbeat > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> API after reading the KIP. There is a new > > >> boolean; > > >>>>>>>>>> the > > >>>>>>>>>>>>>> KIP > > >>>>>>>>>>>>>>>>>>>>> states > > >>>>>>>>>>>>>>>>>>>>>>>>>> that > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> partition ages are returned only when this > > >> boolean > > >>>>>>>>>> is > > >>>>>>>>>>>>>> set. > > >>>>>>>>>>>>>>>>>>>>>>>>>> Implicitly, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> this > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> means that when the consumer receives a new > > >>>>>>>>>> partition, > > >>>>>>>>>>>>> it > > >>>>>>>>>>>>>>>>> will > > >>>>>>>>>>>>>>>>>>>>>>>>>> issue a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> new > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> HB request with the boolean set to receive > > >> the > > >>>>>>>>>> ages. > > >>>>>>>>>>> Is > > >>>>>>>>>>>>>> my > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> understanding > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> correct? We should perhaps clarify the flow > > >> and > > >>>>>>>>>> also > > >>>>>>>>>>>>>> explain > > >>>>>>>>>>>>>>>>>>>>> how it > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> fits > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> into the existing flow (e.g. list offsets, > > >> fetch > > >>>>>>>>>>>>> offsets, > > >>>>>>>>>>>>>>>>>>> etc.). > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> DJ02: It my understanding is correct, I > > >> wonder if > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> the ConsumerGroupHeartbeat API is the right > > >> place > > >>>>>>>>>> for > > >>>>>>>>>>>>>> this > > >>>>>>>>>>>>>>>>>>> given > > >>>>>>>>>>>>>>>>>>>>>>>>>> that > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> a new > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> round trip is done anyway. Alternatively, > > >> it could > > >>>>>>>>>>>>> simply > > >>>>>>>>>>>>>>>>>>>>> include > > >>>>>>>>>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> metadata. Generally, we should be rather > > >> cautious > > >>>>>>>>>>> about > > >>>>>>>>>>>>>> not > > >>>>>>>>>>>>>>>>>>>>>>>>>> overloading > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> the ConsumerGroupHeartbeat API with > > >> unrelated > > >>>>>>>>>>> concepts. > > >>>>>>>>>>>>>> The > > >>>>>>>>>>>>>>>>>>> API > > >>>>>>>>>>>>>>>>>>>>> is > > >>>>>>>>>>>>>>>>>>>>>>>>>> a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> control plane API for assigning or revoking > > >>>>>>>>>>> partitions. > > >>>>>>>>>>>>>> The > > >>>>>>>>>>>>>>>>>>> fact > > >>>>>>>>>>>>>>>>>>>>>>>>>> that > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> we > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> don't want to add it to the corresponding > > >> Streams > > >>>>>>>>>> API > > >>>>>>>>>>>>>> also > > >>>>>>>>>>>>>>>>>>>>> suggests > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> something is not quite right. What would we > > >> do if > > >>>>>>>>>> we > > >>>>>>>>>>>>>> want to > > >>>>>>>>>>>>>>>>>>>>>>>>>> support > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Streams in the future? > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Best, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> David > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> On Wed, Apr 29, 2026 at 12:28 AM > > >> Muralidhar Basani > > >>>>>>>>>>> via > > >>>>>>>>>>>>>> dev > > >>>>>>>>>>>>>>>>> < > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> [email protected]> wrote: > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Hi Jiunn, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Thank you for this great kip. Good to know > > >> about > > >>>>>>>>>> the > > >>>>>>>>>>>>>> gap. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> mb-0 - why a new v2 version bump for > > >>>>>>>>>>>>>> RequestPartitionAges > > >>>>>>>>>>>>>>>>>>>>> field. > > >>>>>>>>>>>>>>>>>>>>>>>>>> Can a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> tagged field (for ex: on response, > > >> PartitionAges > > >>>>>>>>>> on > > >>>>>>>>>>>>>>>>>>>>>>>>>> TopicPartitions) > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> be > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> used here and avoid version bump? > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> mb-1 - For the new config, is there a > > >> recommended > > >>>>>>>>>>>>> value > > >>>>>>>>>>>>>> or > > >>>>>>>>>>>>>>>>> a > > >>>>>>>>>>>>>>>>>>>>>>>>>> ConfigDef > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> validator? Probably it should based on the > > >>>>>>>>>>>>>>>>>>> metadata.max.age.ms > > >>>>>>>>>> < > > >> > > https://urldefense.com/v3/__http://metadata.max.age.ms__;!!Ayb5sqE7!ryUSIElKDF-DJJHgYwYXwp4XEBXpXuBOnZd18PJoMNH4LZ1gc-pDbbdfb2eme_dRSvdvI3bkflKEb5SK$ > > >>> > > >>>>>>>>>>>>>>>>>>>>> ? > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> Sizing > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> instructions can be part of javadocs I > > >> guess. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> mb-2 - (minor) As there are no changes to > > >> Kafka > > >>>>>>>>>>>>> Streams, > > >>>>>>>>>>>>>>>>>>> would > > >>>>>>>>>>>>>>>>>>>>> it > > >>>>>>>>>>>>>>>>>>>>>>>>>> be > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> better > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> to add this new config > > >>>>>>>>>>>>> auto.offset.reset.latest.max.age > > >>>>>>>>>>>>>> to > > >>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> StreamsConfig block list > > >>>>>>>>>>>>>>>>>>>>>>>>>> (NON_CONFIGURABLE_CONSUMER_DEFAULT_CONFIGS) > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> for a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> clear warning, incase users configure it? > > >> This is > > >>>>>>>>>> the > > >>>>>>>>>>>>>> most > > >>>>>>>>>>>>>>>>>>>>>>>>>> familiar > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> consumer config and users might easily > > >> mistakenly > > >>>>>>>>>>>>>> configure > > >>>>>>>>>>>>>>>>>>>>> it. Or > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> may be > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> it's not worth it to add. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> mb-3 - (minor) The phrasing "the consumer > > >> falls > > >>>>>>>>>> back > > >>>>>>>>>>>>> to > > >>>>>>>>>>>>>>>>>>>>> earliest" > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> reads as > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> if the config were being changed > > >> per-partition > > >>>>>>>>>> which > > >>>>>>>>>>>>>> isn't > > >>>>>>>>>>>>>>>>>>>>>>>>>> supported. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> May > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> be rephrasing to something like "consumer > > >> resolves > > >>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>> initial > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> position to > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> start offset for that partition" as if > > >> earliest > > >>>>>>>>>> was > > >>>>>>>>>>>>>> applied > > >>>>>>>>>>>>>>>>>>> to > > >>>>>>>>>>>>>>>>>>>>>>>>>> that > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> partition only and auto.offset.reset > > >> config is > > >>>>>>>>>>>>>> unchanged. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Thanks, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Murali > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> On Tue, Apr 28, 2026 at 2:48 PM 黃竣陽 < > > >>>>>>>>>>>>>> [email protected]> > > >>>>>>>>>>>>>>>>>>>>> wrote: > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Hi chia, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I have updated the KIP to include this > > >> change. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Best Regards, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Chia-Ping Tsai <[email protected]> 於 > > >>>>>>>>>> 2026年4月28日 > > >>>>>>>>>>>>>> 晚上8:03 > > >>>>>>>>>>>>>>>>>>> 寫道： > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> hi Jiunn-Yang > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> chia_0: Should we expose the partition > > >> creation > > >>>>>>>>>>> time > > >>>>>>>>>>>>>> via > > >>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>> Admin > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> API? > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I assume it would be valuable for users > > to > > >>>>>>>>>> diagnose > > >>>>>>>>>>>>> and > > >>>>>>>>>>>>>>>>>>>>>>>>>> troubleshoot > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> behavior of > > >> auto.offset.reset.latest.max.age > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Best, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Chia-Ping > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> On 2026/04/28 10:47:58 黃竣陽 wrote: > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Hello everyone, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I would like to start a discussion on > > >> KIP-1327 > > >>>>>>>>>>>>>> Prevent > > >>>>>>>>>>>>>>>>> Hot > > >>>>>>>>>>>>>>>>>>>>> Data > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> Loss > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> on > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Partition Expansion for Latest Policy > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> < > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>> > > >>>>>>>>>> > > >> > > https://urldefense.com/v3/__https://cwiki.apache.org/confluence/x/KY4mGQ__;!!Ayb5sqE7!qF4q1QzF1RRgP61D7A2xuEai1ky7fepKDKFFvpNBuePikH-ULmT87TvuuZzy5kau5E4y5zMZAmfQQiwZomM$ > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> This proposal aims to introduces > > >>>>>>>>>>>>>>>>>>>>>>>>>> auto.offset.reset.latest.max.age, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> a > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> consumer config that lets the > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> latest reset policy distinguish newly > > >> expanded > > >>>>>>>>>>>>> (hot) > > >>>>>>>>>>>>>>>>>>>>> partitions > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> from > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> long-existing (cold) ones. Partitions > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> younger than the configured threshold > > >>>>>>>>>>> automatically > > >>>>>>>>>>>>>> fall > > >>>>>>>>>>>>>>>>>>>>> back > > >>>>>>>>>>>>>>>>>>>>>>>>>> to > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> earliest, preventing silent data loss > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> during topic expansion without forcing > > >> a full > > >>>>>>>>>>>>>> historical > > >>>>>>>>>>>>>>>>>>>>>>>>>> reprocess. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Best regards, > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Jiunn-Yang > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>> > > >>>>>>>>>>> > > >>>>>>>>>> > > >>>>>>>>> > > >>>>>> > > >>>>>> > > >>>>>> > > >>>> > > >>> > > >>> > > >>> > > >> > > > > >
