Hi, Artem, Luke, Thanks for the reply.
11. If we get rid of batch.max.size and increase the default batch.size, it's true the behavior is slightly different than before. However, does that difference matter to most of our users? In your example, if a user sets linger.ms to 100ms and thinks 256KB is good for throughput, does it matter to deliver any batch smaller than 256KB before 100ms? I also find it a bit hard to explain to our users these 3 different settings related to batch size. Thanks, Jun On Thu, Dec 9, 2021 at 5:47 AM Luke Chen <show...@gmail.com> wrote: > Hi Jun, > > 11. In addition to Artem's comment, I think the reason to have additional > "batch.max.size" is to have more flexibility to users. > For example: > With linger.ms=100ms, batch.size=16KB, now, we have 20KB of data coming to > a partition within 50ms. Now, sender is ready to pick up the batch to send. > In current design, we send 16KB data to broker, and keep the remaining 4KB > in the producer, to keep accumulating data. > But after this KIP, user can send the whole 20KB of data together. That is, > user can decide if they want to accumulate more data before the sender is > ready, and send them together, to have higher throughput. The > "batch.size=16KB" in the proposal, is more like a soft limit, (and > "batch.max.size" is like a hard limit), or it's like a switch to enable the > batch to become ready. Before sender is ready, we can still accumulate more > data, and wrap them together to send to broker. > > User can increase "batch.size" to 20KB to achieve the same goal in the > current design, of course. But you can imagine, if the data within 100ms is > just 18KB, then the batch of data will wait for 100ms passed to be sent > out. This "batch.max.size" config will allow more flexible for user config. > > Does that make sense? > > Thank you. > Luke > > On Thu, Dec 9, 2021 at 7:53 AM Artem Livshits > <alivsh...@confluent.io.invalid> wrote: > > > Hi Jun, > > > > 11. That was my initial thinking as well, but in a discussion some people > > pointed out the change of behavior in some scenarios. E.g. if someone > for > > some reason really wants batches to be at least 16KB and sets large > > linger.ms, and most of the time the batches are filled quickly enough > and > > they observe a certain latency. Then they upgrade their client with a > > default size 256KB and the latency increases. This could be seen as a > > regression. It could be fixed by just reducing linger.ms to specify the > > expected latency, but still could be seen as a disruption by some users. > > The other reason to have 2 sizes is to avoid allocating large buffers > > upfront. > > > > -Artem > > > > On Wed, Dec 8, 2021 at 3:07 PM Jun Rao <j...@confluent.io.invalid> wrote: > > > > > Hi, Artem, > > > > > > Thanks for the reply. > > > > > > 11. Got it. To me, batch.size is really used for throughput and not for > > > latency guarantees. There is no guarantee when 16KB will be > accumulated. > > > So, if users want any latency guarantee, they will need to specify > > > linger.ms accordingly. > > > Then, batch.size can just be used to tune for throughput. > > > > > > 20. Could we also describe the unit of compression? Is > > > it batch.initial.size, batch.size or batch.max.size? > > > > > > Thanks, > > > > > > Jun > > > > > > On Wed, Dec 8, 2021 at 9:58 AM Artem Livshits > > > <alivsh...@confluent.io.invalid> wrote: > > > > > > > Hi Jun, > > > > > > > > 10. My understanding is that MemoryRecords would under the covers be > > > > allocated in chunks, so logically it still would be one MemoryRecords > > > > object, it's just instead of allocating one large chunk upfront, > > smaller > > > > chunks are allocated as needed to grow the batch and linked into a > > list. > > > > > > > > 11. The reason for 2 sizes is to avoid change of behavior when > > triggering > > > > batch send with large linger.ms. Currently, a batch send is > triggered > > > > once > > > > the batch reaches 16KB by default, if we just raise the default to > > 256KB, > > > > then the batch send will be delayed. Using a separate value would > > allow > > > > keeping the current behavior when sending the batch out, but provide > > > better > > > > throughput with high latency + high bandwidth channels. > > > > > > > > -Artem > > > > > > > > On Tue, Dec 7, 2021 at 5:29 PM Jun Rao <j...@confluent.io.invalid> > > wrote: > > > > > > > > > Hi, Luke, > > > > > > > > > > Thanks for the KIP. A few comments below. > > > > > > > > > > 10. Accumulating small batches could improve memory usage. Will > that > > > > > introduce extra copying when generating a produce request? > > Currently, a > > > > > produce request takes a single MemoryRecords per partition. > > > > > 11. Do we need to introduce a new config batch.max.size? Could we > > just > > > > > increase the default of batch.size? We probably need to have > KIP-794 > > > > > < > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-794%3A+Strictly+Uniform+Sticky+Partitioner > > > > > > > > > > > resolved > > > > > before increasing the default batch size since the larger the batch > > > size, > > > > > the worse the problem in KIP-794. > > > > > 12. As for max.request.size, currently it's used for both the max > > > record > > > > > size and the max request size, which is unintuitive. Perhaps we > could > > > > > introduce a new config max.record.size that defaults to 1MB. We > could > > > > then > > > > > increase max.request.size to sth like 10MB. > > > > > > > > > > Thanks, > > > > > > > > > > Jun > > > > > > > > > > > > > > > On Mon, Nov 29, 2021 at 6:02 PM Artem Livshits > > > > > <alivsh...@confluent.io.invalid> wrote: > > > > > > > > > > > Hi Luke, > > > > > > > > > > > > I don't mind increasing the max.request.size to a higher number, > > e.g. > > > > 2MB > > > > > > could be good. I think we should also run some benchmarks to see > > the > > > > > > effects of different sizes. > > > > > > > > > > > > I agree that changing round robin to random solves an independent > > > > > existing > > > > > > issue, however the logic in this KIP exacerbates the issue, so > > there > > > is > > > > > > some dependency. > > > > > > > > > > > > -Artem > > > > > > > > > > > > On Wed, Nov 24, 2021 at 12:43 AM Luke Chen <show...@gmail.com> > > > wrote: > > > > > > > > > > > > > Hi Artem, > > > > > > > Yes, I agree if we go with random selection instead of > > round-robin > > > > > > > selection, the latency issue will be more fair. That is, if > there > > > are > > > > > 10 > > > > > > > partitions, the 10th partition will always be the last choice > in > > > each > > > > > > round > > > > > > > in current design, but with random selection, the chance to be > > > > selected > > > > > > is > > > > > > > more fair. > > > > > > > > > > > > > > However, I think that's kind of out of scope with this KIP. > This > > is > > > > an > > > > > > > existing issue, and it might need further discussion to decide > if > > > > this > > > > > > > change is necessary. > > > > > > > > > > > > > > I agree the default 32KB for "batch.max.size" might be not huge > > > > > > improvement > > > > > > > compared with 256KB. I'm thinking, maybe default to "64KB" for > > > > > > > "batch.max.size", and make the documentation clear that if the > > > > > > > "batch.max.size" > > > > > > > is increased, there might be chances that the "ready" > partitions > > > need > > > > > to > > > > > > > wait for next request to send to broker, because of the > > > > > > "max.request.size" > > > > > > > (default 1MB) limitation. "max.request.size" can also be > > considered > > > > to > > > > > > > increase to avoid this issue. What do you think? > > > > > > > > > > > > > > Thank you. > > > > > > > Luke > > > > > > > > > > > > > > On Wed, Nov 24, 2021 at 2:26 AM Artem Livshits > > > > > > > <alivsh...@confluent.io.invalid> wrote: > > > > > > > > > > > > > > > > maybe I can firstly decrease the "batch.max.size" to 32KB > > > > > > > > > > > > > > > > I think 32KB is too small. With 5 in-flight and 100ms > latency > > we > > > > can > > > > > > > > produce 1.6MB/s per partition. With 256KB we can produce > > > 12.8MB/s > > > > > per > > > > > > > > partition. We should probably set up some testing and see if > > > 256KB > > > > > has > > > > > > > > problems. > > > > > > > > > > > > > > > > To illustrate latency dynamics, let's consider a simplified > > > model: > > > > 1 > > > > > > > > in-flight request per broker, produce latency 125ms, 256KB > max > > > > > request > > > > > > > > size, 16 partitions assigned to the same broker, every second > > > 128KB > > > > > is > > > > > > > > produced to each partition (total production rate is > 2MB/sec). > > > > > > > > > > > > > > > > If the batch size is 16KB, then the pattern would be the > > > following: > > > > > > > > > > > > > > > > 0ms - produce 128KB into each partition > > > > > > > > 0ms - take 16KB from each partition send (total 256KB) > > > > > > > > 125ms - complete first 16KB from each partition, send next > 16KB > > > > > > > > 250ms - complete second 16KB, send next 16KB > > > > > > > > ... > > > > > > > > 1000ms - complete 8th 16KB from each partition > > > > > > > > > > > > > > > > from this model it's easy to see that there are 256KB that > are > > > sent > > > > > > > > immediately, 256KB that are sent in 125ms, ... 256KB that are > > > sent > > > > in > > > > > > > > 875ms. > > > > > > > > > > > > > > > > If the batch size is 256KB, then the pattern would be the > > > > following: > > > > > > > > > > > > > > > > 0ms - produce 128KB into each partition > > > > > > > > 0ms - take 128KB each from first 2 partitions and send (total > > > > 256KB) > > > > > > > > 125ms - complete 2 first partitions, send data from next 2 > > > > partitions > > > > > > > > ... > > > > > > > > 1000ms - complete last 2 partitions > > > > > > > > > > > > > > > > even though the pattern is different, there are still 256KB > > that > > > > are > > > > > > sent > > > > > > > > immediately, 256KB that are sent in 125ms, ... 256KB that are > > > sent > > > > in > > > > > > > > 875ms. > > > > > > > > > > > > > > > > Now, in this example if we do strictly round-robin (current > > > > > > > implementation) > > > > > > > > and we have this exact pattern (not sure how often such > regular > > > > > pattern > > > > > > > > would happen in practice -- I would expect that it would be a > > bit > > > > > more > > > > > > > > random), some partitions would experience higher latency than > > > > others > > > > > > (not > > > > > > > > sure how much it would matter in practice -- in the end of > the > > > day > > > > > some > > > > > > > > bytes produced to a topic would have higher latency and some > > > bytes > > > > > > would > > > > > > > > have lower latency). This pattern is easily fixed by > choosing > > > the > > > > > next > > > > > > > > partition randomly instead of using round-robin. > > > > > > > > > > > > > > > > -Artem > > > > > > > > > > > > > > > > On Tue, Nov 23, 2021 at 12:08 AM Luke Chen < > show...@gmail.com> > > > > > wrote: > > > > > > > > > > > > > > > > > Hi Tom, > > > > > > > > > Thanks for your comments. And thanks for Artem's > explanation. > > > > > > > > > Below is my response: > > > > > > > > > > > > > > > > > > > Currently because buffers are allocated using batch.size > it > > > > means > > > > > > we > > > > > > > > can > > > > > > > > > handle records that are that large (e.g. one big record per > > > > batch). > > > > > > > > Doesn't > > > > > > > > > the introduction of smaller buffer sizes > (batch.initial.size) > > > > mean > > > > > a > > > > > > > > > corresponding decrease in the maximum record size that the > > > > producer > > > > > > can > > > > > > > > > handle? > > > > > > > > > > > > > > > > > > Actually, the "batch.size" is only like a threshold to > decide > > > if > > > > > the > > > > > > > > batch > > > > > > > > > is "ready to be sent". That is, even if you set the > > > > > "batch.size=16KB" > > > > > > > > > (default value), users can still send one record sized with > > > 20KB, > > > > > as > > > > > > > long > > > > > > > > > as the size is less than "max.request.size" in producer > > > (default > > > > > > 1MB). > > > > > > > > > Therefore, the introduction of "batch.initial.size" won't > > > > decrease > > > > > > the > > > > > > > > > maximum record size that the producer can handle. > > > > > > > > > > > > > > > > > > > But isn't there the risk that drainBatchesForOneNode > would > > > end > > > > up > > > > > > not > > > > > > > > > sending ready > > > > > > > > > batches well past when they ought to be sent (according to > > > their > > > > > > > > linger.ms > > > > > > > > > ), > > > > > > > > > because it's sending buffers for earlier partitions too > > > > > aggressively? > > > > > > > > > > > > > > > > > > Did you mean that we have a "max.request.size" per request > > > > (default > > > > > > is > > > > > > > > > 1MB), and before this KIP, the request can include 64 > batches > > > in > > > > > > single > > > > > > > > > request ["batch.size"(16KB) * 64 = 1MB], but now, we might > be > > > > able > > > > > to > > > > > > > > > include 32 batches or less, because we aggressively sent > more > > > > > records > > > > > > > in > > > > > > > > > one batch, is that what you meant? That's a really good > point > > > > that > > > > > > I've > > > > > > > > > never thought about. I think your suggestion to go through > > > other > > > > > > > > partitions > > > > > > > > > that just fit "batch.size", or expire "linger.ms" first, > > > before > > > > > > > handling > > > > > > > > > the one that is > "batch.size" limit is not a good way, > > because > > > > it > > > > > > > might > > > > > > > > > cause the one with size > "batch.size" always in the lowest > > > > > priority, > > > > > > > and > > > > > > > > > cause starving issue that the batch won't have chance to > get > > > > sent. > > > > > > > > > > > > > > > > > > I don't have better solution for it, but maybe I can > firstly > > > > > decrease > > > > > > > the > > > > > > > > > "batch.max.size" to 32KB, instead of aggressively 256KB in > > the > > > > KIP. > > > > > > > That > > > > > > > > > should alleviate the problem. And still improve the > > throughput. > > > > > What > > > > > > do > > > > > > > > you > > > > > > > > > think? > > > > > > > > > > > > > > > > > > Thank you. > > > > > > > > > Luke > > > > > > > > > > > > > > > > > > On Tue, Nov 23, 2021 at 9:04 AM Artem Livshits > > > > > > > > > <alivsh...@confluent.io.invalid> wrote: > > > > > > > > > > > > > > > > > > > > I think this KIP would change the behaviour of > producers > > > when > > > > > > there > > > > > > > > are > > > > > > > > > > multiple partitions ready to be sent > > > > > > > > > > > > > > > > > > > > This is correct, the pattern changes and becomes more > > > > > > coarse-grained. > > > > > > > > > But > > > > > > > > > > I don't think it changes fairness over the long run. I > > think > > > > > it's > > > > > > a > > > > > > > > good > > > > > > > > > > idea to change drainIndex to be random rather than round > > > robin > > > > to > > > > > > > avoid > > > > > > > > > > forming patterns where some partitions would consistently > > get > > > > > > higher > > > > > > > > > > latencies than others because they wait longer for their > > > turn. > > > > > > > > > > > > > > > > > > > > If we really wanted to preserve the exact patterns, we > > could > > > > > either > > > > > > > try > > > > > > > > > to > > > > > > > > > > support multiple 16KB batches from one partition per > > request > > > > > > > (probably > > > > > > > > > > would require protocol change to change logic on the > broker > > > for > > > > > > > > duplicate > > > > > > > > > > detection) or try to re-batch 16KB batches from > accumulator > > > > into > > > > > > > larger > > > > > > > > > > batches during send (additional computations) or try to > > > > consider > > > > > > all > > > > > > > > > > partitions assigned to a broker to check if a new batch > > needs > > > > to > > > > > be > > > > > > > > > created > > > > > > > > > > (i.e. compare cumulative batch size from all partitions > > > > assigned > > > > > > to a > > > > > > > > > > broker and create new batch when cumulative size is 1MB, > > more > > > > > > > complex). > > > > > > > > > > > > > > > > > > > > Overall, it seems like just increasing the max batch size > > is > > > a > > > > > > > simpler > > > > > > > > > > solution and it does favor larger batch sizes, which is > > > > > beneficial > > > > > > > not > > > > > > > > > just > > > > > > > > > > for production. > > > > > > > > > > > > > > > > > > > > > ready batches well past when they ought to be sent > > > (according > > > > > to > > > > > > > > their > > > > > > > > > > linger.ms) > > > > > > > > > > > > > > > > > > > > The trigger for marking batches ready to be sent isn't > > > changed > > > > - > > > > > a > > > > > > > > batch > > > > > > > > > is > > > > > > > > > > ready to be sent once it reaches 16KB, so by the time > > larger > > > > > > batches > > > > > > > > > start > > > > > > > > > > forming, linger.ms wouldn't matter much because the > > batching > > > > > goal > > > > > > is > > > > > > > > met > > > > > > > > > > and the batch can be sent immediately. Larger batches > > start > > > > > > forming > > > > > > > > once > > > > > > > > > > the client starts waiting for the server, in which case > > some > > > > data > > > > > > > will > > > > > > > > > wait > > > > > > > > > > its turn to be sent. This will happen for some data > > > regardless > > > > > of > > > > > > > how > > > > > > > > we > > > > > > > > > > pick data to send, the question is just whether we'd have > > > some > > > > > > > > scenarios > > > > > > > > > > where some partitions would consistently experience > higher > > > > > latency > > > > > > > than > > > > > > > > > > others. I think picking drainIndex randomly would > prevent > > > such > > > > > > > > > scenarios. > > > > > > > > > > > > > > > > > > > > -Artem > > > > > > > > > > > > > > > > > > > > On Mon, Nov 22, 2021 at 2:28 AM Tom Bentley < > > > > tbent...@redhat.com > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > Hi Luke, > > > > > > > > > > > > > > > > > > > > > > Thanks for the KIP! > > > > > > > > > > > > > > > > > > > > > > Currently because buffers are allocated using > batch.size > > it > > > > > means > > > > > > > we > > > > > > > > > can > > > > > > > > > > > handle records that are that large (e.g. one big record > > per > > > > > > batch). > > > > > > > > > > Doesn't > > > > > > > > > > > the introduction of smaller buffer sizes > > > (batch.initial.size) > > > > > > mean > > > > > > > a > > > > > > > > > > > corresponding decrease in the maximum record size that > > the > > > > > > producer > > > > > > > > can > > > > > > > > > > > handle? That might not be a problem if the user knows > > their > > > > > > maximum > > > > > > > > > > record > > > > > > > > > > > size and has tuned batch.initial.size accordingly, but > if > > > the > > > > > > > default > > > > > > > > > for > > > > > > > > > > > batch.initial.size < batch.size it could cause > > regressions > > > > for > > > > > > > > existing > > > > > > > > > > > users with a large record size, I think. It should be > > > enough > > > > > for > > > > > > > > > > > batch.initial.size to default to batch.size, allowing > > users > > > > who > > > > > > > care > > > > > > > > > > about > > > > > > > > > > > the memory saving in the off-peak throughput case to do > > the > > > > > > tuning, > > > > > > > > but > > > > > > > > > > not > > > > > > > > > > > causing a regression for existing users. > > > > > > > > > > > > > > > > > > > > > > I think this KIP would change the behaviour of > producers > > > when > > > > > > there > > > > > > > > are > > > > > > > > > > > multiple partitions ready to be sent: By sending all > the > > > > ready > > > > > > > > buffers > > > > > > > > > > > (which may now be > batch.size) for the first > partition, > > we > > > > > could > > > > > > > end > > > > > > > > > up > > > > > > > > > > > excluding ready buffers for other partitions from the > > > current > > > > > > send. > > > > > > > > In > > > > > > > > > > > other words, as I understand the KIP currently, > there's a > > > > > change > > > > > > in > > > > > > > > > > > fairness. I think the code in > > > > > > > > RecordAccumulator#drainBatchesForOneNode > > > > > > > > > > will > > > > > > > > > > > ensure fairness in the long run, because the drainIndex > > > will > > > > > > ensure > > > > > > > > > that > > > > > > > > > > > those other partitions each get their turn at being the > > > > first. > > > > > > But > > > > > > > > > isn't > > > > > > > > > > > there the risk that drainBatchesForOneNode would end up > > not > > > > > > sending > > > > > > > > > ready > > > > > > > > > > > batches well past when they ought to be sent (according > > to > > > > > their > > > > > > > > > > linger.ms > > > > > > > > > > > ), > > > > > > > > > > > because it's sending buffers for earlier partitions too > > > > > > > aggressively? > > > > > > > > > Or, > > > > > > > > > > > to put it another way, perhaps the RecordAccumulator > > should > > > > > > > > round-robin > > > > > > > > > > the > > > > > > > > > > > ready buffers for _all_ the partitions before trying to > > > fill > > > > > the > > > > > > > > > > remaining > > > > > > > > > > > space with the extra buffers (beyond the batch.size > > limit) > > > > for > > > > > > the > > > > > > > > > first > > > > > > > > > > > partitions? > > > > > > > > > > > > > > > > > > > > > > Kind regards, > > > > > > > > > > > > > > > > > > > > > > Tom > > > > > > > > > > > > > > > > > > > > > > On Wed, Oct 20, 2021 at 1:35 PM Luke Chen < > > > show...@gmail.com > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > Hi Ismael and all devs, > > > > > > > > > > > > Is there any comments/suggestions to this KIP? > > > > > > > > > > > > If no, I'm going to update the KIP based on my > previous > > > > mail, > > > > > > and > > > > > > > > > > start a > > > > > > > > > > > > vote tomorrow or next week. > > > > > > > > > > > > > > > > > > > > > > > > Thank you. > > > > > > > > > > > > Luke > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Oct 18, 2021 at 2:40 PM Luke Chen < > > > > show...@gmail.com > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > Hi Ismael, > > > > > > > > > > > > > Thanks for your comments. > > > > > > > > > > > > > > > > > > > > > > > > > > 1. Why do we have to reallocate the buffer? We can > > > keep a > > > > > > list > > > > > > > of > > > > > > > > > > > buffers > > > > > > > > > > > > > instead and avoid reallocation. > > > > > > > > > > > > > -> Do you mean we allocate multiple buffers with > > > > > > > > > > "buffer.initial.size", > > > > > > > > > > > > > and link them together (with linked list)? > > > > > > > > > > > > > ex: > > > > > > > > > > > > > a. We allocate 4KB initial buffer > > > > > > > > > > > > > | 4KB | > > > > > > > > > > > > > > > > > > > > > > > > > > b. when new records reached and the remaining > buffer > > is > > > > not > > > > > > > > enough > > > > > > > > > > for > > > > > > > > > > > > the > > > > > > > > > > > > > records, we create another batch with > > > > "batch.initial.size" > > > > > > > buffer > > > > > > > > > > > > > ex: we already have 3KB of data in the 1st buffer, > > and > > > > here > > > > > > > comes > > > > > > > > > the > > > > > > > > > > > 2KB > > > > > > > > > > > > > record > > > > > > > > > > > > > > > > > > > > > > > > > > | 4KB (1KB remaining) | > > > > > > > > > > > > > now, record: 2KB coming > > > > > > > > > > > > > We fill the 1st 1KB into 1st buffer, and create new > > > > buffer, > > > > > > and > > > > > > > > > > linked > > > > > > > > > > > > > together, and fill the rest of data into it > > > > > > > > > > > > > | 4KB (full) | ---> | 4KB (3KB remaining) | > > > > > > > > > > > > > > > > > > > > > > > > > > Is that what you mean? > > > > > > > > > > > > > If so, I think I like this idea! > > > > > > > > > > > > > If not, please explain more detail about it. > > > > > > > > > > > > > Thank you. > > > > > > > > > > > > > > > > > > > > > > > > > > 2. I think we should also consider tweaking the > > > semantics > > > > > of > > > > > > > > > > batch.size > > > > > > > > > > > > so > > > > > > > > > > > > > that the sent batches can be larger if the batch is > > not > > > > > ready > > > > > > > to > > > > > > > > be > > > > > > > > > > > sent > > > > > > > > > > > > > (while still respecting max.request.size and > perhaps > > a > > > > new > > > > > > > > > > > > max.batch.size). > > > > > > > > > > > > > > > > > > > > > > > > > > --> In the KIP, I was trying to make the > "batch.size" > > > as > > > > > the > > > > > > > > upper > > > > > > > > > > > bound > > > > > > > > > > > > > of the batch size, and introduce a > > "batch.initial.size" > > > > as > > > > > > > > initial > > > > > > > > > > > batch > > > > > > > > > > > > > size. > > > > > > > > > > > > > So are you saying that we can let "batch.size" as > > > initial > > > > > > batch > > > > > > > > > size > > > > > > > > > > > and > > > > > > > > > > > > > introduce a "max.batch.size" as upper bound value? > > > > > > > > > > > > > That's a good suggestion, but that would change the > > > > > semantics > > > > > > > of > > > > > > > > > > > > > "batch.size", which might surprise some users. I > > think > > > my > > > > > > > > original > > > > > > > > > > > > proposal > > > > > > > > > > > > > ("batch.initial.size") is safer for users. What do > > you > > > > > think? > > > > > > > > > > > > > > > > > > > > > > > > > > Thank you. > > > > > > > > > > > > > Luke > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Oct 18, 2021 at 3:12 AM Ismael Juma < > > > > > > ism...@juma.me.uk > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > >> I think we should also consider tweaking the > > semantics > > > > of > > > > > > > > > batch.size > > > > > > > > > > > so > > > > > > > > > > > > >> that the sent batches can be larger if the batch > is > > > not > > > > > > ready > > > > > > > to > > > > > > > > > be > > > > > > > > > > > sent > > > > > > > > > > > > >> (while still respecting max.request.size and > > perhaps a > > > > new > > > > > > > > > > > > >> max.batch.size). > > > > > > > > > > > > >> > > > > > > > > > > > > >> Ismael > > > > > > > > > > > > >> > > > > > > > > > > > > >> On Sun, Oct 17, 2021, 12:08 PM Ismael Juma < > > > > > > ism...@juma.me.uk > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > >> > > > > > > > > > > > > >> > Hi Luke, > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > Thanks for the KIP. Why do we have to reallocate > > the > > > > > > buffer? > > > > > > > > We > > > > > > > > > > can > > > > > > > > > > > > >> keep a > > > > > > > > > > > > >> > list of buffers instead and avoid reallocation. > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > Ismael > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > On Sun, Oct 17, 2021, 2:02 AM Luke Chen < > > > > > > show...@gmail.com> > > > > > > > > > > wrote: > > > > > > > > > > > > >> > > > > > > > > > > > > > >> >> Hi Kafka dev, > > > > > > > > > > > > >> >> I'd like to start the discussion for the > > proposal: > > > > > > KIP-782: > > > > > > > > > > > > Expandable > > > > > > > > > > > > >> >> batch size in producer. > > > > > > > > > > > > >> >> > > > > > > > > > > > > >> >> The main purpose for this KIP is to have better > > > > memory > > > > > > > usage > > > > > > > > in > > > > > > > > > > > > >> producer, > > > > > > > > > > > > >> >> and also save users from the dilemma while > > setting > > > > the > > > > > > > batch > > > > > > > > > size > > > > > > > > > > > > >> >> configuration. After this KIP, users can set a > > > higher > > > > > > > > > batch.size > > > > > > > > > > > > >> without > > > > > > > > > > > > >> >> worries, and of course, with an appropriate > > > > > > > > > "batch.initial.size" > > > > > > > > > > > and > > > > > > > > > > > > >> >> "batch.reallocation.factor". > > > > > > > > > > > > >> >> > > > > > > > > > > > > >> >> Derailed description can be found here: > > > > > > > > > > > > >> >> > > > > > > > > > > > > >> >> > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-782%3A+Expandable+batch+size+in+producer > > > > > > > > > > > > >> >> > > > > > > > > > > > > >> >> Any comments and feedback are welcome. > > > > > > > > > > > > >> >> > > > > > > > > > > > > >> >> Thank you. > > > > > > > > > > > > >> >> Luke > > > > > > > > > > > > >> >> > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
