Hi Chia-Ping, For (1), we do that already, by starting at offset zero. For (2), we will follow the existing auto.offset.reset policy.
But, I know that you folks have more closely researched this area and you've dug into some nasty corner cases for consumer groups. Maybe there are some of those for all group types. I'm happy for share groups to be added to this KIP using a similar technique as for consumer groups. I think it's less critical for share groups, but I am generally in favour of consistency. Thanks, Andrew On 2026/06/29 14:57:43 Chia-Ping Tsai wrote: > Hi Andrew, > > Yes, we can figure out the expanded partitions using > ShareGroupStatePartitionMetadataInfo, but the true question is - should a > share group need a different policy for expanded partitions? > > The challenge encountered by normal consumers with the latest policy is that > sometimes users want to reset to 0, and sometimes it is required to set to > latest. > > 1) The former happens when an expanded partition is dynamically added to an > active group. Users often expect to consume from the very beginning of this > new partition to avoid missing data, even if the overall group policy is > latest. > 2) The latter happens when a group's state is completely wiped (e.g., when > offsets expire for normal consumers, or when a share group is manually > deleted and recreated). In this scenario, they want a consistent latest > offset behavior across both old and newly expanded partitions. > > Given these distinct user expectations, does it make sense to consider a more > granular offset reset strategy specifically for partition expansion in share > groups? > > Best, > Chia-Ping > > On 2026/06/29 07:20:40 Andrew Schofield wrote: > > Hi Jun, > > This is handled because share groups do not support regex subscriptions :) > > I think this KIP is a nice improvement, but I also think that we don't need > > it for share groups with their current behaviour. I am perfectly amenable > > to having it extended to cover share groups too, but I don't think it will > > make a practical difference. > > > > Thanks, > > Andrew > > > > On 2026/06/26 18:57:54 Jun Rao via dev wrote: > > > Hi, Andrew, > > > > > > There is another case where a share consumer subscribes to a regex and a > > > new topic is later created that matches that regex. Intuitively, they > > > should use the earliest offset for consumption. But how does the share > > > coordinator distinguish these from existing topics explicitly added by the > > > user without the creation timestamp? > > > > > > Thanks, > > > > > > Jun > > > > > > On Fri, Jun 26, 2026 at 11:00 AM Andrew Schofield <[email protected]> > > > wrote: > > > > > > > Hi Jun, > > > > When a user adds an existing topic to a share group subscription, we do > > > > use the auto.offset.reset policy because those partitions already exist > > > > and > > > > may well have data on them. We only use 0 in the case where a topic > > > > already > > > > being consumed gained some additional new partitions. These partitions > > > > will > > > > be empty at the time of creation, so zero seems like a reasonable > > > > starting > > > > point. Partitions being consumed in a share group always have a known > > > > starting position once assigned. We don't have the equivalent of a > > > > consumer > > > > group not having a committed offset. > > > > > > > > Thanks, > > > > Andrew > > > > > > > > On 2026/06/26 17:36:31 Jun Rao via dev wrote: > > > > > Hi, Andrew, > > > > > > > > > > Thanks for the reply. > > > > > > > > > > I am not sure it's always a good idea to start new partitions with > > > > offset 0 > > > > > for the share group. For example, once a share group starts, a user > > > > > could > > > > > add a subscription to an existing topic. That existing topic could > > > > > have a > > > > > large backlog and starting it with offset 0 forces the user to consume > > > > that > > > > > entire backlog. In KIP-1327, such a partition will be treated as an > > > > > existing partition and will follow the auto.offset.reset policy. This > > > > seems > > > > > more intuitive. It would be useful to consider if the share group > > > > > should > > > > > adopt the same policy. > > > > > > > > > > Jun > > > > > > > > > > On Fri, Jun 26, 2026 at 3:42 AM Andrew Schofield > > > > > <[email protected]> > > > > > wrote: > > > > > > > > > > > Hi Jiunn-Yang et al., > > > > > > Some background on the problem I hinted at for the KIP-932 > > > > implementation. > > > > > > 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 (which is of course both the > > > > earliest > > > > > > and latest offset for an empty topic-partition). This means there > > > > > > is no > > > > > > doubt about what happens when the number of partitions is > > > > > > increased." > > > > > > > > > > > > The problem was that we had not implemented the use of 0, but > > > > > > instead > > > > were > > > > > > using the share.auto.offset.reset config to choose the initial > > > > > > offset > > > > in > > > > > > this case. We write a ShareGroupStatePartitionMetadata record when a > > > > topic > > > > > > is first being initialized for consumption by a share group, and > > > > > > this > > > > > > contains a list of the partitions which we are initializing. As a > > > > result, I > > > > > > believe we can already tell when partitions are added, and we do > > > > > > know > > > > when > > > > > > to initialize to 0 as it says in the KIP. We will put in a patch > > > > > > that > > > > uses > > > > > > 0 as intended. > > > > > > > > > > > > I do not mind whether we want to incorporate share groups into > > > > KIP-1327, > > > > > > but I do not think that it is necessary to do so. > > > > > > > > > > > > Thanks, > > > > > > Andrew > > > > > > > > > > > > On 2026/06/26 04:31:28 Chia-Ping Tsai wrote: > > > > > > > > JR5. Since this changes the on-disk data format for > > > > PartitionRecord, we > > > > > > > > need to gate this by a new MV. It also changes the format of > > > > > > > > ConsumerGroupMetadataValue, so we need to gate it too. I'm not > > > > sure if > > > > > > this > > > > > > > > requires a new MV or a new GV. > > > > > > > > > > > > > > That is a good point. If we want to maintain consistency for the > > > > > > NewPartitions field when the group coordinator migrates between new > > > > and old > > > > > > binaries, a version gate is definitely required. For example: > > > > > > > > > > > > > > GV_2(2, MetadataVersion.IBP_4_4_IV0, Map.of()) > > > > > > > > > > > > > > The group coordinator should NOT set the NewPartitions field when > > > > the gv > > > > > > is smaller than gv_2 > > > > > > > > > > > > > > Best, > > > > > > > Chia-Ping > > > > > > > > > > > > > > On 2026/06/25 20:01:39 Jun Rao via dev wrote: > > > > > > > > Hi, Jiunn-Yang, > > > > > > > > > > > > > > > > JR2. We should try to maintain consistency across our APIs. So, > > > > > > > > it > > > > > > would be > > > > > > > > useful to understand if the user-facing part of this KIP is what > > > > share > > > > > > > > consumer wants too. It would be problematic if we proceed with > > > > > > > > this > > > > > > > > approach only for the share consumer to choose a different one > > > > later. > > > > > > > > > > > > > > > > JR3. I was thinking that if we add the NewPartitions field in > > > > > > > > GroupHeartbeatResponse, there is no need to expose the > > > > group/partition > > > > > > > > creation timestamp to other RPCs and the Cli. > > > > > > > > > > > > > > > > JR5. Since this changes the on-disk data format for > > > > PartitionRecord, we > > > > > > > > need to gate this by a new MV. It also changes the format of > > > > > > > > ConsumerGroupMetadataValue, so we need to gate it too. I'm not > > > > sure if > > > > > > this > > > > > > > > requires a new MV or a new GV. > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > Jun > > > > > > > > > > > > > > > > On Thu, Jun 25, 2026 at 5:52 AM 黃竣陽 <[email protected]> wrote: > > > > > > > > > > > > > > > > > Hello Jun, chia, > > > > > > > > > > > > > > > > > > Thanks for your feedback. > > > > > > > > > > > > > > > > > > JR3 JR4 I have updated the KIP. > > > > > > > > > > > > > > > > > > JR2 The new-partition detection mechanism is reusable. The > > > > > > coordinator > > > > > > > > > already has > > > > > > > > > access to both timestamps required for classification, so the > > > > > > > > > determination can be made > > > > > > > > > server-side without introducing any new RPCs. The main > > > > difference is > > > > > > where > > > > > > > > > the policy is > > > > > > > > > enforced: modern consumer resolves it on the client, whereas a > > > > share > > > > > > group > > > > > > > > > resolves the > > > > > > > > > starting offset on the partition leader. As a result, the > > > > > > classification > > > > > > > > > decision would need to > > > > > > > > > be propagated through the existing share-state initialization > > > > path. > > > > > > We > > > > > > > > > would also need to persist > > > > > > > > > the group's creation time as part of the share-group state, > > > > > > > > > since > > > > > > that > > > > > > > > > information is not stored today. > > > > > > > > > > > > > > > > > > None of this is a blocker, but it does require changes to the > > > > > > share-state > > > > > > > > > format and introduces > > > > > > > > > a share-specific configuration. Given that additional scope, I > > > > would > > > > > > > > > prefer to keep share groups out > > > > > > > > > of scope for this KIP and address them in a follow-up effort, > > > > while > > > > > > > > > documenting the relevant reuse > > > > > > > > > opportunities here. > > > > > > > > > > > > > > > > > > Best Regards, > > > > > > > > > Jiunn-Yang > > > > > > > > > > > > > > > > > > > Chia-Ping Tsai <[email protected]> 於 2026年6月25日 下午1:31 寫道： > > > > > > > > > > > > > > > > > > > >> 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. > > > > > > > > > > > > > > > > > > > > Thinking more about the mirror cluster scenario we > > > > > > > > > > discussed, I > > > > > > realize > > > > > > > > > it introduces significant complexity. Handling it properly > > > > > > > > > would > > > > > > require a > > > > > > > > > tolerance time window rather than a strict time interval to > > > > account > > > > > > for > > > > > > > > > replication lag. To prevent scope creep and keep KIP-1327 > > > > focused on > > > > > > its > > > > > > > > > primary goal, I think it would be best to defer the > > > > > > multi-cluster/mirroring > > > > > > > > > scenario and explore those approaches in a separate KIP > > > > > > > > > > > > > > > > > > > > On 2026/06/24 21:29:19 Chia-Ping Tsai wrote: > > > > > > > > > >> 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 > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>>>>> > > > > > > > > > >>>>>>>>>> > > > > > > > > > >>>>>>>>>> > > > > > > > > > >>>>>>>>>> > > > > > > > > > >>>>>>>> > > > > > > > > > >>>>>>> > > > > > > > > > >>>>>>> > > > > > > > > > >>>>>>> > > > > > > > > > >>>>>> > > > > > > > > > >>>> > > > > > > > > > >>>> > > > > > > > > > >>> > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
