Hi Anna, I think there is value if CRC for only user bytes can be used. This will help when we have future protocol updates. Otherwise any protocol migration might break auditing if it largely relies on CRC including system bytes.
I did some test to understand the performance overhead of having a separate user bytes CRC, On my desktop, it took ~4.7 seconds to compute CRC for 10G bytes. So for each megabyte it takes 0.47 ms. To compare with compression cost, I used the compressor used by producer. The test uses GZIP and compress 1MB of data for each batch. It takes: ~90 seconds to compress 10GB bytes that contains all same byte. ~470 seconds to compress 10GB bytes containing random bytes. >1000 seconds to compress 10GB bytes with 4, 8, 16, 32 and 64 patterns. (I guess it takes time to update the pattern mapping) So the overhead of a separate CRC computing is <1% considering the producer do a lot of things other than compression. I am not sure if this overhead is worth taking or not, because we do have a huge number of messages to send, so any overhead should be avoided if possible. BTW. Another interesting finding is that the Crc32 class used in clients which used to be faster than java CRC32 in Java 1.6. It seems no longer the case. What I see is that Java CRC32 class is 2x faster than the Crc32 class we are using now. Thanks, Jiangjie (Becket) Qin On Fri, Jan 29, 2016 at 1:46 PM, Anna Povzner <a...@confluent.io> wrote: > Joel, thanks for your feedback. I updated the wiki based on your comments > about the wiki writeup. > > > On Fri, Jan 29, 2016 at 11:50 AM, Anna Povzner <a...@confluent.io> wrote: > > > Becket, > > > > In your scenario with one message from producer A and one message from > > producer B, those are two different messages, and they should be tracked > as > > two different messages. So I would argue for using record CRC -- CRC that > > is actually used by the system + it will not require computing a > different > > CRC again which will add performance overhead. > > > > If the broker ever changes the CRC, the scenarios when that happens > should > > be very well defined. As far as I know, the scenarios when CRC is > > overwritten by the broker (including KIP-31/32 changes): > > -- topic config is LogAppendTime for timestamp type > > -- upgrade/downgrade > > -- compression codec change (which could be inferred from config). > > > > Monitoring/audit just needs to know when CRCs are safe to use, which is > > most often is known from config. In the future, this can be further > > addressed by broker interceptors. > > > > Thanks, > > Anna > > > > > > > > > > On Fri, Jan 29, 2016 at 11:30 AM, Becket Qin <becket....@gmail.com> > wrote: > > > >> Neha, > >> > >> CRC is definitely an important type of metadata of a record. I am not > >> arguing about that. But I think we should distinguish between two types > of > >> checksum here, 1) the checksum of user data. and 2) the checksum > including > >> system appended bytes. > >> > >> I completely agree that (1) is good to add. But I am not sure if we > should > >> expose (2) to user, because this means any underlying protocol change > will > >> give a different CRC for exact same message. For example, let's say > >> producer A is sending message with timestamp. Producer B is sending > >> message > >> without timestamp. Even they are given the exact same message, the CRC > >> returned would be different. > >> > >> Also, Kafka broker will modify the system appended bytes in different > >> scenarios, such as compression codec change, message format > >> conversion(After KIP-31 and KIP-32). > >> > >> So my concern is that we are exposing CRC which including system > appended > >> bytes to user. > >> > >> Other than this I think everything looks good. Nice work, Anna. > >> > >> Thanks, > >> > >> Jiangjie (Becket) Qin > >> > >> On Fri, Jan 29, 2016 at 8:11 AM, Joel Koshy <jjkosh...@gmail.com> > wrote: > >> > >> > Responding to some of the earlier comments in the thread: > >> > > >> > @Jay/@Neha, > >> > > >> > I think any one of onCommit/onAppend/onArrival would work for the > >> concrete > >> > use-case that I had outlined. I think onArrival is additionally useful > >> for > >> > custom validation - i.e., reject the message and do not append if it > >> > violates some cluster-specific rule (for e.g., if some header > timestamp > >> is > >> > older than xyz). However, the thing with user-supplied validation is > we > >> > would have to do with a (new) generic error code in the producer > >> response. > >> > While there is a risk of a broker interceptor having high latency I > >> think > >> > that is acceptable since it is the user's responsibility to ensure low > >> > latency - the producer call-back and onAcknowledgment interceptor are > >> > similar in this regard although those are less risky. Even so, I think > >> > there are clear use-cases for broker interceptors so I feel the risk > >> part > >> > is something that just needs to be documented. @Jay that is a good > point > >> > about moving from Message/MessageSet to Records although that may be > >> less > >> > difficult to absorb since it is a broker-side interceptor and so > people > >> > don't need to get a ton of applications in their company to switch to > >> use > >> > it. > >> > > >> > Re: onEnqueued: monitoring serialization latency can be done via > metrics > >> > but this is more useful for recording whether serialization succeeded > or > >> > not. onAcknowledgment subsumes this but it also subsumes other > possible > >> > errors (such as produce errors). It is more fine-grained than most > >> people > >> > need though (i.e., I don't think we will use it even if it is > present.) > >> > > >> > Re: checksums: I think it is a good addition to metadata; and for > >> > low-volume or super-critical topics can be used for very strict > >> auditing. > >> > > >> > There are a couple of typos/edits for the wiki itself: > >> > > >> > - Under Kafka Producer changes: > >> > - you have references to KafkaConsumer constructor and > >> > ConsumerConfig.originals. > >> > - sendRecord -> sentRecord (may be clearer) > >> > - Under ProducerInterceptor interface: there is a mention of > >> onEnqueued > >> > which was rejected > >> > - Comment for ConsumerRecord.record should probably be: // NEW: > >> record > >> > size in bytes (*after decompression*) > >> > > >> > > >> > BTW - Anna, nice work on the KIP! > >> > > >> > Joel > >> > > >> > On Fri, Jan 29, 2016 at 6:57 AM, Neha Narkhede <n...@confluent.io> > >> wrote: > >> > > >> > > Becket, > >> > > > >> > > Is your concern the presence of CRC in the RecordMetadata or do you > >> want > >> > to > >> > > brainstorm how CRC can be used for auditing? I think we shouldn't > try > >> to > >> > > think about the various ways that people can do monitoring using > >> > > interceptors and the metadata we provide. The entire point of having > >> > > pluggable interceptors is so that people can employ their own > creative > >> > > mechanisms to make use of interceptors. > >> > > > >> > > I do think that it is worth discussing whether or not CRC makes > sense > >> as > >> > > record metadata to the user. My take is that the CRC is the best > >> > size-bound > >> > > summary of serialized record content available to us which is > >> expensive > >> > to > >> > > recompute if the user were to redo it. I'd argue this summary of a > >> record > >> > > qualifies as its metadata. After all, we use the record CRC for a > very > >> > > important test of the system durability as it travels through the > >> system. > >> > > > >> > > 1. Isn't the TopicPartition + Offset already uniquely identified a > >> > message? > >> > > > It seems better than CRC no matter from summary point of view or > >> > auditing > >> > > > point of view. > >> > > > >> > > > >> > > The offset is a system-assigned value of uniqueness to the message. > If > >> > you > >> > > trusted the system that much, you are not looking to monitor it > >> > out-of-band > >> > > :-) > >> > > > >> > > > >> > > > 2. Currently CRC only has 4 bytes. So it will have collision when > >> there > >> > > are > >> > > > more than ~4 billion messages. Take LinkedIn as an example, we > have > >> 1.3 > >> > > > trillion messages per day. So there will be at least a couple of > >> > hundreds > >> > > > collision for each CRC code every day, whereas > TopicPartition+Offset > >> > will > >> > > > not have any collision. > >> > > > >> > > > >> > > The CRC isn't sent over the wire and doesn't add any extra overhead > in > >> > > processing, so what is your concern? If you aren't convinced about > its > >> > > usefulness, you can always use the default do-nothing interceptor at > >> > > LinkedIn and ignore the CRC. > >> > > > >> > > Without having > >> > > > the entire message bytes, they may not be able to verify its > >> > correctness, > >> > > > and the CRC could even be invalid if the broker ever overwritten > any > >> > > field > >> > > > or did format conversion. > >> > > > > >> > > > >> > > This doesn't make sense to me. The CRC is used for the most > important > >> > > durability check by Kafka - to verify that the message was not > garbled > >> > over > >> > > the wire. The system can't change it; it has to match on the > consumer > >> > side > >> > > or we will not return it to the user. > >> > > > >> > > On Fri, Jan 29, 2016 at 3:23 AM, Becket Qin <becket....@gmail.com> > >> > wrote: > >> > > > >> > > > Anna, > >> > > > > >> > > > It is still not clear to me why we should expose CRC to end user. > >> > > > Followings are my confusions. > >> > > > > >> > > > 1. Isn't the TopicPartition + Offset already uniquely identified a > >> > > message? > >> > > > It seems better than CRC no matter from summary point of view or > >> > auditing > >> > > > point of view. > >> > > > > >> > > > 2. Currently CRC only has 4 bytes. So it will have collision when > >> there > >> > > are > >> > > > more than ~4 billion messages. Take LinkedIn as an example, we > have > >> 1.3 > >> > > > trillion messages per day. So there will be at least a couple of > >> > hundreds > >> > > > collision for each CRC code every day, whereas > TopicPartition+Offset > >> > will > >> > > > not have any collision. > >> > > > > >> > > > 3. CRC is calculated after all the fields have been filled in by > >> > > producer, > >> > > > including timestamp, attributes, etc. It might also get recomputed > >> on > >> > > > broker side. So if users only get CRC from record metadata. > Without > >> > > having > >> > > > the entire message bytes, they may not be able to verify its > >> > correctness, > >> > > > and the CRC could even be invalid if the broker ever overwritten > any > >> > > field > >> > > > or did format conversion. > >> > > > > >> > > > Thanks, > >> > > > > >> > > > Jiangjie (Becket) Qin > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > On Thu, Jan 28, 2016 at 5:58 PM, Anna Povzner <a...@confluent.io> > >> > wrote: > >> > > > > >> > > > > On a second thought, yes, I think we should expose record size > >> that > >> > > > > represents application bytes. This is Becket's option #1. > >> > > > > > >> > > > > I updated the KIP wiki with new fields in RecordMetadata and > >> > > > > ConsumerRecord. > >> > > > > > >> > > > > I would like to start a voting thread tomorrow if there are no > >> > > objections > >> > > > > or more things to discuss. > >> > > > > > >> > > > > Thanks, > >> > > > > Anna > >> > > > > > >> > > > > > >> > > > > > >> > > > > On Thu, Jan 28, 2016 at 2:25 PM, Anna Povzner < > a...@confluent.io> > >> > > wrote: > >> > > > > > >> > > > > > Regarding record size as bytes sent over the wire, my concern > is > >> > that > >> > > > it > >> > > > > > is almost impossible to calculate per-record. We could do as: > 1) > >> > > > > compressed > >> > > > > > bytes / number of records in a compressed message, as Todd > >> > mentioned; > >> > > > or > >> > > > > 2) > >> > > > > > or same as #1 but take it proportional to uncompressed record > >> size > >> > > vs. > >> > > > > > total uncompressed size of records. All of these calculations > >> give > >> > us > >> > > > an > >> > > > > > estimate. So maybe record size as bytes sent over the wire is > >> not a > >> > > > > > per-record metadata, but rather per topic/partition measure > >> that is > >> > > > > better > >> > > > > > to be exposed through metrics? > >> > > > > > > >> > > > > > > >> > > > > > On Thu, Jan 28, 2016 at 2:09 PM, Todd Palino < > tpal...@gmail.com > >> > > >> > > > wrote: > >> > > > > > > >> > > > > >> It may be difficult (or nearly impossible) to get actual > >> > compressed > >> > > > > bytes > >> > > > > >> for a message from a compressed batch, but I do think it’s > >> useful > >> > > > > >> information to have available for the very reason noted, > >> bandwidth > >> > > > > >> consumed. Does it make sense to have an interceptor at the > >> batch > >> > > level > >> > > > > >> that > >> > > > > >> can provide this? The other option is to estimate it (such as > >> > making > >> > > > an > >> > > > > >> assumption that the messages in a batch are equal in size, > >> which > >> > is > >> > > > not > >> > > > > >> necessarily true), which is probably not the right answer. > >> > > > > >> > >> > > > > >> -Todd > >> > > > > >> > >> > > > > >> > >> > > > > >> On Thu, Jan 28, 2016 at 1:48 PM, Anna Povzner < > >> a...@confluent.io> > >> > > > > wrote: > >> > > > > >> > >> > > > > >> > Hi Becket, > >> > > > > >> > > >> > > > > >> > It will be up to the interceptor to implement their audit > or > >> > > > > monitoring > >> > > > > >> > strategy. I would also imagine there is more than one good > >> way > >> > to > >> > > do > >> > > > > >> audit. > >> > > > > >> > So, I agree that some of the interceptors may not use CRC, > >> and > >> > we > >> > > > will > >> > > > > >> not > >> > > > > >> > require it. The question is now whether intercepting CRCs > is > >> > > > needed. I > >> > > > > >> > think they are very useful for monitoring and audit, > because > >> CRC > >> > > > > >> provides > >> > > > > >> > an a easy way to get a summary of a message, rather than > >> using > >> > > > message > >> > > > > >> > bytes or key/value objects. > >> > > > > >> > > >> > > > > >> > Regarding record size, I agree that bandwidth example was > >> not a > >> > > good > >> > > > > >> one. I > >> > > > > >> > think it would be hard to get actual bytes sent over the > wire > >> > > (your > >> > > > > #2), > >> > > > > >> > since multiple records get compressed together and we would > >> need > >> > > to > >> > > > > >> decide > >> > > > > >> > which bytes to account to which record. So I am inclined to > >> only > >> > > do > >> > > > > your > >> > > > > >> > #1. However, it still makes more sense to me just to return > >> > record > >> > > > > size > >> > > > > >> > including the header, since this is the actual record size. > >> > > > > >> > > >> > > > > >> > Thanks, > >> > > > > >> > Anna > >> > > > > >> > > >> > > > > >> > On Thu, Jan 28, 2016 at 11:46 AM, Becket Qin < > >> > > becket....@gmail.com> > >> > > > > >> wrote: > >> > > > > >> > > >> > > > > >> > > Anna, > >> > > > > >> > > > >> > > > > >> > > Using CRC to do end2end auditing might be very costly > >> because > >> > > you > >> > > > > will > >> > > > > >> > need > >> > > > > >> > > to collect all the CRC from both producer and consumer. > >> And it > >> > > is > >> > > > > >> based > >> > > > > >> > on > >> > > > > >> > > the assumption that broker does not modify the record. > >> > > > > >> > > Can you shed some idea on how end to end auditing will be > >> > using > >> > > > the > >> > > > > >> CRC > >> > > > > >> > > before we decide to expose such low level detail to the > end > >> > > user? > >> > > > It > >> > > > > >> > would > >> > > > > >> > > also be helpful if you can compare it with something like > >> > > sequence > >> > > > > >> number > >> > > > > >> > > based auditing. > >> > > > > >> > > > >> > > > > >> > > About the record size, one thing worth notice is that the > >> size > >> > > of > >> > > > > >> Record > >> > > > > >> > is > >> > > > > >> > > not the actual bytes sent over the wire if we use > >> compression. > >> > > So > >> > > > > that > >> > > > > >> > does > >> > > > > >> > > not really tell user how much bandwidth they are using. > >> > > > Personally I > >> > > > > >> > think > >> > > > > >> > > two kinds of size may be useful. > >> > > > > >> > > 1. The record size after serialization, i.e. application > >> > bytes. > >> > > > (The > >> > > > > >> > > uncompressed record size can be easily derived as well) > >> > > > > >> > > 2. The actual bytes sent over the wire. > >> > > > > >> > > We can get (1) easily, but (2) is difficult to get at > >> Record > >> > > level > >> > > > > >> when > >> > > > > >> > we > >> > > > > >> > > use compression. > >> > > > > >> > > > >> > > > > >> > > Thanks, > >> > > > > >> > > > >> > > > > >> > > Jiangjie (Becket) Qin > >> > > > > >> > > > >> > > > > >> > > On Thu, Jan 28, 2016 at 10:55 AM, Anna Povzner < > >> > > a...@confluent.io > >> > > > > > >> > > > > >> > wrote: > >> > > > > >> > > > >> > > > > >> > > > Hi Becket, > >> > > > > >> > > > > >> > > > > >> > > > The use-case for CRC is end-to-end audit, rather than > >> > checking > >> > > > > >> whether > >> > > > > >> > a > >> > > > > >> > > > single message is corrupt or not. > >> > > > > >> > > > > >> > > > > >> > > > Regarding record size, I was thinking to extract record > >> size > >> > > > from > >> > > > > >> > Record. > >> > > > > >> > > > That will include header overhead as well. I think > total > >> > > record > >> > > > > size > >> > > > > >> > will > >> > > > > >> > > > tell users how much bandwidth their messages take. > Since > >> > > header > >> > > > is > >> > > > > >> > > > relatively small and constant, users also will get an > >> idea > >> > of > >> > > > > their > >> > > > > >> > > > key/value sizes. > >> > > > > >> > > > > >> > > > > >> > > > Thanks, > >> > > > > >> > > > Anna > >> > > > > >> > > > > >> > > > > >> > > > On Thu, Jan 28, 2016 at 9:29 AM, Becket Qin < > >> > > > becket....@gmail.com > >> > > > > > > >> > > > > >> > > wrote: > >> > > > > >> > > > > >> > > > > >> > > > > I am +1 on #1.2 and #3. > >> > > > > >> > > > > > >> > > > > >> > > > > #2: Regarding CRC, I am not sure if users care about > >> CRC. > >> > is > >> > > > > there > >> > > > > >> > any > >> > > > > >> > > > > specific use case? Currently we validate messages by > >> > calling > >> > > > > >> > > > ensureValid() > >> > > > > >> > > > > to verify the checksum and throw exception if it does > >> not > >> > > > match. > >> > > > > >> > > > > > >> > > > > >> > > > > Message size would be useful. We can add that to > >> > > > ConsumerRecord. > >> > > > > >> Can > >> > > > > >> > > you > >> > > > > >> > > > > clarify the message size you are referring to? Does > it > >> > > include > >> > > > > the > >> > > > > >> > > > message > >> > > > > >> > > > > header overhead or not? From user's point of view, > they > >> > > > probably > >> > > > > >> > don't > >> > > > > >> > > > care > >> > > > > >> > > > > about header size. > >> > > > > >> > > > > > >> > > > > >> > > > > Thanks, > >> > > > > >> > > > > > >> > > > > >> > > > > Jiangjie (Becket) Qin > >> > > > > >> > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > On Wed, Jan 27, 2016 at 8:26 PM, Neha Narkhede < > >> > > > > n...@confluent.io > >> > > > > >> > > >> > > > > >> > > > wrote: > >> > > > > >> > > > > > >> > > > > >> > > > > > Anna, > >> > > > > >> > > > > > > >> > > > > >> > > > > > Thanks for being diligent. > >> > > > > >> > > > > > > >> > > > > >> > > > > > +1 on #1.2 and sounds good on #3. I recommend > adding > >> > > > checksum > >> > > > > >> and > >> > > > > >> > > size > >> > > > > >> > > > > > fields to RecordMetadata and ConsumerRecord instead > >> of > >> > > > > exposing > >> > > > > >> > > > metadata > >> > > > > >> > > > > > piecemeal in the interceptor APIs. > >> > > > > >> > > > > > > >> > > > > >> > > > > > Thanks, > >> > > > > >> > > > > > Neha > >> > > > > >> > > > > > > >> > > > > >> > > > > > On Wed, Jan 27, 2016 at 4:10 PM, Anna Povzner < > >> > > > > >> a...@confluent.io> > >> > > > > >> > > > wrote: > >> > > > > >> > > > > > > >> > > > > >> > > > > > > Hi All, > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > The KIP wiki page is now up-to-date with the > scope > >> we > >> > > have > >> > > > > >> agreed > >> > > > > >> > > on: > >> > > > > >> > > > > > > Producer and Consumer Interceptors with a minimal > >> set > >> > of > >> > > > > >> mutable > >> > > > > >> > > API > >> > > > > >> > > > > that > >> > > > > >> > > > > > > are not dependent on producer and consumer > internal > >> > > > > >> > implementation. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > I have few more API details that I would like to > >> bring > >> > > > > >> attention > >> > > > > >> > to > >> > > > > >> > > > > > or/and > >> > > > > >> > > > > > > discuss: > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > 1. Handling exceptions > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > Exceptions can provide an additional level of > >> control. > >> > > For > >> > > > > >> > example, > >> > > > > >> > > > we > >> > > > > >> > > > > > can > >> > > > > >> > > > > > > filter messages on consumer side or stop messages > >> on > >> > > > > producer > >> > > > > >> if > >> > > > > >> > > they > >> > > > > >> > > > > > don’t > >> > > > > >> > > > > > > have the right field. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > I see two options: > >> > > > > >> > > > > > > 1.1. For callbacks that can mutate records > (onSend > >> and > >> > > > > >> > onConsume), > >> > > > > >> > > > > > > propagate exceptions through the original calls > >> > > > > >> > > (KafkaProducer.send() > >> > > > > >> > > > > and > >> > > > > >> > > > > > > KafkaConsumer.poll() respectively). For other > >> > callbacks, > >> > > > > catch > >> > > > > >> > > > > exception, > >> > > > > >> > > > > > > log, and ignore. > >> > > > > >> > > > > > > 1.2. Catch exceptions from all the interceptor > >> > callbacks > >> > > > and > >> > > > > >> > > ignore. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > The issue with 1.1. is that it effectively > changes > >> > > > > >> > > > KafkaProducer.send() > >> > > > > >> > > > > > and > >> > > > > >> > > > > > > KafkaConsumer.poll() API, since now they may > throw > >> > > > > exceptions > >> > > > > >> > that > >> > > > > >> > > > are > >> > > > > >> > > > > > not > >> > > > > >> > > > > > > documented in KafkaProducer/Consumer API. Another > >> > option > >> > > > is > >> > > > > to > >> > > > > >> > > allow > >> > > > > >> > > > to > >> > > > > >> > > > > > > propagate some exceptions, and ignore others. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > I think our use-cases do not require propagating > >> > > > exceptions. > >> > > > > >> So, > >> > > > > >> > I > >> > > > > >> > > > > > propose > >> > > > > >> > > > > > > option 1.2. Unless someone has > suggestion/use-cases > >> > for > >> > > > > >> > propagating > >> > > > > >> > > > > > > exceptions. Please let me know. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > 2. Intercepting record CRC and record size > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > Since we decided not to add any intermediate > >> callbacks > >> > > > (such > >> > > > > >> as > >> > > > > >> > > > > onEnqueue > >> > > > > >> > > > > > > or onReceive) to interceptors, I think it is > still > >> > > > valuable > >> > > > > to > >> > > > > >> > > > > intercept > >> > > > > >> > > > > > > record CRC and record size in bytes for > monitoring > >> and > >> > > > audit > >> > > > > >> > > > use-cases. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > I propose to add checksum and size fields to > >> > > > RecordMetadata > >> > > > > >> and > >> > > > > >> > > > > > > ConsumerRecord. Another option would be to add > >> them as > >> > > > > >> parameters > >> > > > > >> > > in > >> > > > > >> > > > > > > onAcknowledgement() and onConsume() callbacks. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > 3. Callbacks that allow to modify records look as > >> > > follows: > >> > > > > >> > > > > > > ProducerRecord<K, V> onSend(ProducerRecord<K, V> > >> > > record); > >> > > > > >> > > > > > > ConsumerRecords<K, V> > onConsume(ConsumerRecords<K, > >> V> > >> > > > > >> records); > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > This means that interceptors can potentially > modify > >> > > > > >> > topic/partition > >> > > > > >> > > > in > >> > > > > >> > > > > > > ProducerRecord and topic/partition/offset in > >> > > > > ConsumerRecord. I > >> > > > > >> > > > propose > >> > > > > >> > > > > > that > >> > > > > >> > > > > > > it is up to the interceptor implementation to > >> ensure > >> > > that > >> > > > > >> > > > > > topic/partition, > >> > > > > >> > > > > > > etc is correct. KafkaProducer.send() will use > >> topic, > >> > > > > >> partition, > >> > > > > >> > > key, > >> > > > > >> > > > > and > >> > > > > >> > > > > > > value from ProducerRecord returned from the > >> onSend(). > >> > > > > >> Similarly, > >> > > > > >> > > > > > > ConsumerRecords returned from > KafkaConsumer.poll() > >> > would > >> > > > be > >> > > > > >> the > >> > > > > >> > > ones > >> > > > > >> > > > > > > returned from the interceptor. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > Please let me know if you have any suggestions or > >> > > > objections > >> > > > > >> to > >> > > > > >> > the > >> > > > > >> > > > > > above. > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > Thanks, > >> > > > > >> > > > > > > Anna > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > On Wed, Jan 27, 2016 at 2:56 PM, Anna Povzner < > >> > > > > >> a...@confluent.io > >> > > > > >> > > > >> > > > > >> > > > > wrote: > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > > Hi Mayuresh, > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > > I see why you would want to check for messages > >> left > >> > in > >> > > > the > >> > > > > >> > > > > > > > RecordAccumulator. However, I don't think this > >> will > >> > > > > >> completely > >> > > > > >> > > > solve > >> > > > > >> > > > > > the > >> > > > > >> > > > > > > > problem. Messages could be in-flight somewhere > >> else, > >> > > > like > >> > > > > in > >> > > > > >> > the > >> > > > > >> > > > > > socket, > >> > > > > >> > > > > > > or > >> > > > > >> > > > > > > > there maybe in-flight messages on the consumer > >> side > >> > of > >> > > > the > >> > > > > >> > > > > MirrorMaker. > >> > > > > >> > > > > > > So, > >> > > > > >> > > > > > > > if we go the route of checking whether there > are > >> any > >> > > > > >> in-flight > >> > > > > >> > > > > messages > >> > > > > >> > > > > > > for > >> > > > > >> > > > > > > > topic deletion use-case, maybe it is better > count > >> > them > >> > > > > with > >> > > > > >> > > > onSend() > >> > > > > >> > > > > > and > >> > > > > >> > > > > > > > onAcknowledge() -- whether all messages sent > were > >> > > > > >> > acknowledged. I > >> > > > > >> > > > > also > >> > > > > >> > > > > > > > think that it would be better to solve this > >> without > >> > > > > >> > interceptors, > >> > > > > >> > > > > such > >> > > > > >> > > > > > as > >> > > > > >> > > > > > > > fix error handling in this scenario. However, I > >> do > >> > not > >> > > > > have > >> > > > > >> any > >> > > > > >> > > > good > >> > > > > >> > > > > > > > proposal right now, so these are just general > >> > > thoughts. > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > > Thanks, > >> > > > > >> > > > > > > > Anna > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > > On Wed, Jan 27, 2016 at 11:18 AM, Mayuresh > >> Gharat < > >> > > > > >> > > > > > > > gharatmayures...@gmail.com> wrote: > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> Calling producer.flush(), flushes all the > data. > >> So > >> > > this > >> > > > > is > >> > > > > >> OK. > >> > > > > >> > > But > >> > > > > >> > > > > > when > >> > > > > >> > > > > > > >> you > >> > > > > >> > > > > > > >> are running Mirror maker, I am not sure there > >> is a > >> > > way > >> > > > to > >> > > > > >> > > flush() > >> > > > > >> > > > > from > >> > > > > >> > > > > > > >> outside. > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> Thanks, > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> Mayuresh > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> On Wed, Jan 27, 2016 at 11:08 AM, Becket Qin < > >> > > > > >> > > > becket....@gmail.com> > >> > > > > >> > > > > > > >> wrote: > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> > Mayuresh, > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > Regarding your use case about mirror maker. > >> Is it > >> > > > good > >> > > > > >> > enough > >> > > > > >> > > as > >> > > > > >> > > > > > long > >> > > > > >> > > > > > > >> as we > >> > > > > >> > > > > > > >> > know there is no message for the topic in > the > >> > > > producer > >> > > > > >> > > anymore? > >> > > > > >> > > > If > >> > > > > >> > > > > > > that > >> > > > > >> > > > > > > >> is > >> > > > > >> > > > > > > >> > the case, call producer.flush() is > sufficient. > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > Thanks, > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > Jiangjie (Becket) Qin > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > On Tue, Jan 26, 2016 at 6:18 PM, Mayuresh > >> Gharat > >> > < > >> > > > > >> > > > > > > >> > gharatmayures...@gmail.com > >> > > > > >> > > > > > > >> > > wrote: > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > > Hi Anna, > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > Thanks a lot for summarizing the > discussion > >> on > >> > > this > >> > > > > >> kip. > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > It LGTM. > >> > > > > >> > > > > > > >> > > This is really nice : > >> > > > > >> > > > > > > >> > > We decided not to add any callbacks to > >> producer > >> > > and > >> > > > > >> > consumer > >> > > > > >> > > > > > > >> > > interceptors that will depend on internal > >> > > > > >> implementation > >> > > > > >> > as > >> > > > > >> > > > part > >> > > > > >> > > > > > of > >> > > > > >> > > > > > > >> this > >> > > > > >> > > > > > > >> > > KIP. > >> > > > > >> > > > > > > >> > > *However, it is possible to add them later > >> as > >> > > part > >> > > > of > >> > > > > >> > > another > >> > > > > >> > > > > KIP > >> > > > > >> > > > > > if > >> > > > > >> > > > > > > >> > there > >> > > > > >> > > > > > > >> > > are good use-cases.* > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > Do you agree with the use case I explained > >> > > earlier > >> > > > > for > >> > > > > >> > > knowing > >> > > > > >> > > > > the > >> > > > > >> > > > > > > >> number > >> > > > > >> > > > > > > >> > > of records left in the RecordAccumulator > >> for a > >> > > > > >> particular > >> > > > > >> > > > topic. > >> > > > > >> > > > > > It > >> > > > > >> > > > > > > >> might > >> > > > > >> > > > > > > >> > > be orthogonal to this KIP, but will be > >> helpful. > >> > > > What > >> > > > > do > >> > > > > >> > you > >> > > > > >> > > > > think? > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > Thanks, > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > Mayuresh > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > On Tue, Jan 26, 2016 at 2:46 PM, Todd > >> Palino < > >> > > > > >> > > > tpal...@gmail.com > >> > > > > >> > > > > > > >> > > > > >> > > > > > > >> wrote: > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > > This looks good. As noted, having one > >> mutable > >> > > > > >> > interceptor > >> > > > > >> > > on > >> > > > > >> > > > > > each > >> > > > > >> > > > > > > >> side > >> > > > > >> > > > > > > >> > > > allows for the use cases we can envision > >> > right > >> > > > now, > >> > > > > >> and > >> > > > > >> > I > >> > > > > >> > > > > think > >> > > > > >> > > > > > > >> that’s > >> > > > > >> > > > > > > >> > > > going to provide a great deal of > >> opportunity > >> > > for > >> > > > > >> > > > implementing > >> > > > > >> > > > > > > things > >> > > > > >> > > > > > > >> > like > >> > > > > >> > > > > > > >> > > > audit, especially within a multi-tenant > >> > > > > environment. > >> > > > > >> > > Looking > >> > > > > >> > > > > > > >> forward to > >> > > > > >> > > > > > > >> > > > getting this available in the clients. > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > Thanks! > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > -Todd > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > On Tue, Jan 26, 2016 at 2:36 PM, Anna > >> > Povzner < > >> > > > > >> > > > > > a...@confluent.io> > >> > > > > >> > > > > > > >> > wrote: > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > > Hi All, > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > Here is meeting notes from today’s KIP > >> > > meeting: > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > 1. We agreed to keep the scope of this > >> KIP > >> > to > >> > > > be > >> > > > > >> > > producer > >> > > > > >> > > > > and > >> > > > > >> > > > > > > >> > consumer > >> > > > > >> > > > > > > >> > > > > interceptors only. Broker-side > >> interceptor > >> > > will > >> > > > > be > >> > > > > >> > added > >> > > > > >> > > > > later > >> > > > > >> > > > > > > as > >> > > > > >> > > > > > > >> a > >> > > > > >> > > > > > > >> > > > > separate KIP. The reasons were already > >> > > > mentioned > >> > > > > in > >> > > > > >> > this > >> > > > > >> > > > > > thread, > >> > > > > >> > > > > > > >> but > >> > > > > >> > > > > > > >> > > the > >> > > > > >> > > > > > > >> > > > > summary is: > >> > > > > >> > > > > > > >> > > > > * Broker interceptor is riskier and > >> > requires > >> > > > > >> careful > >> > > > > >> > > > > > > >> consideration > >> > > > > >> > > > > > > >> > > about > >> > > > > >> > > > > > > >> > > > > overheads, whether to intercept > leaders > >> vs. > >> > > > > >> > > > > leaders/replicas, > >> > > > > >> > > > > > > >> what to > >> > > > > >> > > > > > > >> > > do > >> > > > > >> > > > > > > >> > > > on > >> > > > > >> > > > > > > >> > > > > leader failover and so on. > >> > > > > >> > > > > > > >> > > > > * Broker interceptors increase > >> monitoring > >> > > > > >> resolution, > >> > > > > >> > > but > >> > > > > >> > > > > not > >> > > > > >> > > > > > > >> > > including > >> > > > > >> > > > > > > >> > > > it > >> > > > > >> > > > > > > >> > > > > in this KIP does not reduce usefulness > >> of > >> > > > > producer > >> > > > > >> and > >> > > > > >> > > > > > consumer > >> > > > > >> > > > > > > >> > > > > interceptors that enable end-to-end > >> > > monitoring > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > 2. We agreed to scope > >> ProducerInterceptor > >> > and > >> > > > > >> > > > > > > ConsumerInterceptor > >> > > > > >> > > > > > > >> > > > callbacks > >> > > > > >> > > > > > > >> > > > > to minimal set of mutable API that are > >> not > >> > > > > >> dependent > >> > > > > >> > on > >> > > > > >> > > > > > producer > >> > > > > >> > > > > > > >> and > >> > > > > >> > > > > > > >> > > > > consumer internal implementation. > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > ProducerInterceptor: > >> > > > > >> > > > > > > >> > > > > *ProducerRecord<K, V> > >> > > onSend(ProducerRecord<K, > >> > > > V> > >> > > > > >> > > > record);* > >> > > > > >> > > > > > > >> > > > > *void onAcknowledgement(RecordMetadata > >> > > > metadata, > >> > > > > >> > > Exception > >> > > > > >> > > > > > > >> > exception);* > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > ConsumerInterceptor: > >> > > > > >> > > > > > > >> > > > > *ConsumerRecords<K, V> > >> > > > > >> onConsume(ConsumerRecords<K, V> > >> > > > > >> > > > > > > records);* > >> > > > > >> > > > > > > >> > > > > *void onCommit(Map<TopicPartition, > >> > > > > >> OffsetAndMetadata> > >> > > > > >> > > > > > offsets);* > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > We will allow interceptors to modify > >> > > > > >> ProducerRecord on > >> > > > > >> > > > > > producer > >> > > > > >> > > > > > > >> side, > >> > > > > >> > > > > > > >> > > and > >> > > > > >> > > > > > > >> > > > > modify ConsumerRecords on consumer > side. > >> > This > >> > > > > will > >> > > > > >> > > support > >> > > > > >> > > > > > > >> end-to-end > >> > > > > >> > > > > > > >> > > > > monitoring and auditing and support > the > >> > > ability > >> > > > > to > >> > > > > >> add > >> > > > > >> > > > > > metadata > >> > > > > >> > > > > > > >> for a > >> > > > > >> > > > > > > >> > > > > message. This will support Todd’s > >> Auditing > >> > > and > >> > > > > >> Routing > >> > > > > >> > > > > > > use-cases. > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > We did not find any use-case for > >> modifying > >> > > > > records > >> > > > > >> in > >> > > > > >> > > > > > > onConsume() > >> > > > > >> > > > > > > >> > > > callback, > >> > > > > >> > > > > > > >> > > > > but decided to enable modification of > >> > > consumer > >> > > > > >> records > >> > > > > >> > > for > >> > > > > >> > > > > > > >> symmetry > >> > > > > >> > > > > > > >> > > with > >> > > > > >> > > > > > > >> > > > > onSend(). > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > 3. We agreed to ensure compatibility > >> > when/if > >> > > we > >> > > > > add > >> > > > > >> > new > >> > > > > >> > > > > > methods > >> > > > > >> > > > > > > to > >> > > > > >> > > > > > > >> > > > > ProducerInterceptor and > >> ConsumerInterceptor > >> > > by > >> > > > > >> using > >> > > > > >> > > > default > >> > > > > >> > > > > > > >> methods > >> > > > > >> > > > > > > >> > > with > >> > > > > >> > > > > > > >> > > > > an empty implementation. Ok to assume > >> Java > >> > 8. > >> > > > > >> (This is > >> > > > > >> > > > > > Ismael’s > >> > > > > >> > > > > > > >> > method > >> > > > > >> > > > > > > >> > > > #2). > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > 4. We decided not to add any callbacks > >> to > >> > > > > producer > >> > > > > >> and > >> > > > > >> > > > > > consumer > >> > > > > >> > > > > > > >> > > > > interceptors that will depend on > >> internal > >> > > > > >> > implementation > >> > > > > >> > > > as > >> > > > > >> > > > > > part > >> > > > > >> > > > > > > >> of > >> > > > > >> > > > > > > >> > > this > >> > > > > >> > > > > > > >> > > > > KIP. However, it is possible to add > them > >> > > later > >> > > > as > >> > > > > >> part > >> > > > > >> > > of > >> > > > > >> > > > > > > another > >> > > > > >> > > > > > > >> KIP > >> > > > > >> > > > > > > >> > > if > >> > > > > >> > > > > > > >> > > > > there are good use-cases. > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > *Reasoning.* We did not have concrete > >> > > use-cases > >> > > > > >> that > >> > > > > >> > > > > justified > >> > > > > >> > > > > > > >> more > >> > > > > >> > > > > > > >> > > > methods > >> > > > > >> > > > > > > >> > > > > at this point. Some of the use-cases > >> were > >> > for > >> > > > > more > >> > > > > >> > > > > fine-grain > >> > > > > >> > > > > > > >> latency > >> > > > > >> > > > > > > >> > > > > collection, which could be done with > >> Kafka > >> > > > > Metrics. > >> > > > > >> > > > Another > >> > > > > >> > > > > > > >> use-case > >> > > > > >> > > > > > > >> > > was > >> > > > > >> > > > > > > >> > > > > encryption. However, there are several > >> > design > >> > > > > >> options > >> > > > > >> > > for > >> > > > > >> > > > > > > >> encryption. > >> > > > > >> > > > > > > >> > > One > >> > > > > >> > > > > > > >> > > > > is to do per-record encryption which > >> would > >> > > > > require > >> > > > > >> > > adding > >> > > > > >> > > > > > > >> > > > > ProducerInterceptor.onEnqueued() and > >> > > > > >> > > > > > > >> ConsumerInterceptor.onReceive(). > >> > > > > >> > > > > > > >> > > One > >> > > > > >> > > > > > > >> > > > > could argue that in that case > encryption > >> > > could > >> > > > be > >> > > > > >> done > >> > > > > >> > > by > >> > > > > >> > > > > > > adding a > >> > > > > >> > > > > > > >> > > custom > >> > > > > >> > > > > > > >> > > > > serializer/deserializer. Another > option > >> is > >> > to > >> > > > do > >> > > > > >> > > > encryption > >> > > > > >> > > > > > > after > >> > > > > >> > > > > > > >> > > message > >> > > > > >> > > > > > > >> > > > > gets compressed, but there are issues > >> that > >> > > > arise > >> > > > > >> > > regarding > >> > > > > >> > > > > > > broker > >> > > > > >> > > > > > > >> > doing > >> > > > > >> > > > > > > >> > > > > re-compression. We decided that it is > >> > better > >> > > to > >> > > > > >> have > >> > > > > >> > > that > >> > > > > >> > > > > > > >> discussion > >> > > > > >> > > > > > > >> > > in a > >> > > > > >> > > > > > > >> > > > > separate KIP and decide that this is > >> > > something > >> > > > we > >> > > > > >> want > >> > > > > >> > > to > >> > > > > >> > > > do > >> > > > > >> > > > > > > with > >> > > > > >> > > > > > > >> > > > > interceptors or by other means. > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > Todd, Mayuresh and others who missed > the > >> > KIP > >> > > > > >> meeting, > >> > > > > >> > > > please > >> > > > > >> > > > > > let > >> > > > > >> > > > > > > >> me > >> > > > > >> > > > > > > >> > > know > >> > > > > >> > > > > > > >> > > > > your thoughts on the scope we agreed > on > >> > > during > >> > > > > the > >> > > > > >> > > > meeting. > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > I will update the KIP proposal with > the > >> > > current > >> > > > > >> > decision > >> > > > > >> > > > by > >> > > > > >> > > > > > end > >> > > > > >> > > > > > > of > >> > > > > >> > > > > > > >> > > today. > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > Anna > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > On Tue, Jan 26, 2016 at 11:41 AM, > >> Mayuresh > >> > > > > Gharat < > >> > > > > >> > > > > > > >> > > > > gharatmayures...@gmail.com> wrote: > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > > Hi, > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > I won't be able to make it to KIP > >> hangout > >> > > due > >> > > > > to > >> > > > > >> > > > conflict. > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > Anna, here is the use case where > >> knowing > >> > if > >> > > > > there > >> > > > > >> > are > >> > > > > >> > > > > > messages > >> > > > > >> > > > > > > >> in > >> > > > > >> > > > > > > >> > the > >> > > > > >> > > > > > > >> > > > > > RecordAccumulator left to be sent to > >> the > >> > > > kafka > >> > > > > >> > cluster > >> > > > > >> > > > > for a > >> > > > > >> > > > > > > >> topic > >> > > > > >> > > > > > > >> > is > >> > > > > >> > > > > > > >> > > > > > useful. > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > 1) Consider a pipeline : > >> > > > > >> > > > > > > >> > > > > > A ---> Mirror-maker -----> B > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > 2) We have a topic T in cluster A > >> > mirrored > >> > > to > >> > > > > >> > cluster > >> > > > > >> > > B. > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > 3) Now if we delete topic T in A and > >> > > > > immediately > >> > > > > >> > > proceed > >> > > > > >> > > > > to > >> > > > > >> > > > > > > >> delete > >> > > > > >> > > > > > > >> > > the > >> > > > > >> > > > > > > >> > > > > > topic in cluster B, some of the the > >> > > > > Mirror-maker > >> > > > > >> > > > machines > >> > > > > >> > > > > > die > >> > > > > >> > > > > > > >> > because > >> > > > > >> > > > > > > >> > > > > > atleast one of the batches in > >> > > > RecordAccumulator > >> > > > > >> for > >> > > > > >> > > > topic > >> > > > > >> > > > > T > >> > > > > >> > > > > > > >> fail to > >> > > > > >> > > > > > > >> > > be > >> > > > > >> > > > > > > >> > > > > > produced to cluster B. We have seen > >> this > >> > > > > >> happening > >> > > > > >> > in > >> > > > > >> > > > our > >> > > > > >> > > > > > > >> clusters. > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > If we know that there are no more > >> > messages > >> > > > left > >> > > > > >> in > >> > > > > >> > the > >> > > > > >> > > > > > > >> > > > RecordAccumulator > >> > > > > >> > > > > > > >> > > > > to > >> > > > > >> > > > > > > >> > > > > > be produced to cluster B, we can > >> safely > >> > > > delete > >> > > > > >> the > >> > > > > >> > > topic > >> > > > > >> > > > > in > >> > > > > >> > > > > > > >> > cluster B > >> > > > > >> > > > > > > >> > > > > > without disturbing the pipeline. > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > Mayuresh > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > On Tue, Jan 26, 2016 at 10:31 AM, > Anna > >> > > > Povzner > >> > > > > < > >> > > > > >> > > > > > > >> a...@confluent.io> > >> > > > > >> > > > > > > >> > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > > Thanks Ismael and Todd for your > >> > feedback! > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > I agree about coming up with lean, > >> but > >> > > > useful > >> > > > > >> > > > interfaces > >> > > > > >> > > > > > > that > >> > > > > >> > > > > > > >> > will > >> > > > > >> > > > > > > >> > > be > >> > > > > >> > > > > > > >> > > > > > easy > >> > > > > >> > > > > > > >> > > > > > > to extend later. > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > When we discuss the minimal set of > >> > > producer > >> > > > > and > >> > > > > >> > > > consumer > >> > > > > >> > > > > > > >> > > interceptor > >> > > > > >> > > > > > > >> > > > > API > >> > > > > >> > > > > > > >> > > > > > in > >> > > > > >> > > > > > > >> > > > > > > today’s KIP meeting (discussion > >> item #2 > >> > > in > >> > > > my > >> > > > > >> > > previous > >> > > > > >> > > > > > > email), > >> > > > > >> > > > > > > >> > lets > >> > > > > >> > > > > > > >> > > > > > compare > >> > > > > >> > > > > > > >> > > > > > > two options: > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > *1. Minimal set of immutable API > for > >> > > > producer > >> > > > > >> and > >> > > > > >> > > > > consumer > >> > > > > >> > > > > > > >> > > > > interceptors* > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > ProducerInterceptor: > >> > > > > >> > > > > > > >> > > > > > > public void > >> onSend(ProducerRecord<K, V> > >> > > > > >> record); > >> > > > > >> > > > > > > >> > > > > > > public void > >> > > > onAcknowledgement(RecordMetadata > >> > > > > >> > > metadata, > >> > > > > >> > > > > > > >> Exception > >> > > > > >> > > > > > > >> > > > > > > exception); > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > ConsumerInterceptor: > >> > > > > >> > > > > > > >> > > > > > > public void > >> > onConsume(ConsumerRecords<K, > >> > > V> > >> > > > > >> > > records); > >> > > > > >> > > > > > > >> > > > > > > public void > >> > onCommit(Map<TopicPartition, > >> > > > > >> > > > > > OffsetAndMetadata> > >> > > > > >> > > > > > > >> > > offsets); > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > Use-cases: > >> > > > > >> > > > > > > >> > > > > > > — end-to-end monitoring; custom > >> tracing > >> > > and > >> > > > > >> > logging > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > *2. Minimal set of mutable API for > >> > > producer > >> > > > > and > >> > > > > >> > > > consumer > >> > > > > >> > > > > > > >> > > > interceptors* > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > ProducerInterceptor: > >> > > > > >> > > > > > > >> > > > > > > ProducerRecord<K, V> > >> > > > onSend(ProducerRecord<K, > >> > > > > >> V> > >> > > > > >> > > > > record); > >> > > > > >> > > > > > > >> > > > > > > void > >> onAcknowledgement(RecordMetadata > >> > > > > metadata, > >> > > > > >> > > > > Exception > >> > > > > >> > > > > > > >> > > exception); > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > ConsumerInterceptor: > >> > > > > >> > > > > > > >> > > > > > > void onConsume(ConsumerRecords<K, > V> > >> > > > > records); > >> > > > > >> > > > > > > >> > > > > > > void onCommit(Map<TopicPartition, > >> > > > > >> > OffsetAndMetadata> > >> > > > > >> > > > > > > offsets); > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > Additional use-cases to #1: > >> > > > > >> > > > > > > >> > > > > > > — Ability to add metadata to a > >> message > >> > or > >> > > > > fill > >> > > > > >> in > >> > > > > >> > > > > standard > >> > > > > >> > > > > > > >> fields > >> > > > > >> > > > > > > >> > > for > >> > > > > >> > > > > > > >> > > > > > audit > >> > > > > >> > > > > > > >> > > > > > > and routing. > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > Implications > >> > > > > >> > > > > > > >> > > > > > > — Partition assignment will be > done > >> > based > >> > > > on > >> > > > > >> > > modified > >> > > > > >> > > > > > > >> key/value > >> > > > > >> > > > > > > >> > > > instead > >> > > > > >> > > > > > > >> > > > > > of > >> > > > > >> > > > > > > >> > > > > > > original key/value. If key/value > >> > > > > >> transformation is > >> > > > > >> > > not > >> > > > > >> > > > > > > >> consistent > >> > > > > >> > > > > > > >> > > > (same > >> > > > > >> > > > > > > >> > > > > > key > >> > > > > >> > > > > > > >> > > > > > > and value does not mutate to the > >> same, > >> > > but > >> > > > > >> > modified, > >> > > > > >> > > > > > > >> key/value), > >> > > > > >> > > > > > > >> > > then > >> > > > > >> > > > > > > >> > > > > log > >> > > > > >> > > > > > > >> > > > > > > compaction would not work. > However, > >> > audit > >> > > > and > >> > > > > >> > > routing > >> > > > > >> > > > > > > >> use-cases > >> > > > > >> > > > > > > >> > > from > >> > > > > >> > > > > > > >> > > > > Todd > >> > > > > >> > > > > > > >> > > > > > > will likely do consistent > >> > transformation. > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > *Additional callbacks (discussion > >> item > >> > #3 > >> > > > in > >> > > > > my > >> > > > > >> > > > previous > >> > > > > >> > > > > > > >> email):* > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > If we want to support encryption, > we > >> > > would > >> > > > > >> want to > >> > > > > >> > > be > >> > > > > >> > > > > able > >> > > > > >> > > > > > > to > >> > > > > >> > > > > > > >> > > modify > >> > > > > >> > > > > > > >> > > > > > > serialized key/value, rather than > >> key > >> > and > >> > > > > value > >> > > > > >> > > > objects. > >> > > > > >> > > > > > > This > >> > > > > >> > > > > > > >> > will > >> > > > > >> > > > > > > >> > > > add > >> > > > > >> > > > > > > >> > > > > > the > >> > > > > >> > > > > > > >> > > > > > > following API to producer and > >> consumer > >> > > > > >> > interceptors: > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > ProducerInterceptor: > >> > > > > >> > > > > > > >> > > > > > > SerializedKeyValue > >> > > > onEnqueued(TopicPartition > >> > > > > >> tp, > >> > > > > >> > > > > > > >> > ProducerRecord<K, > >> > > > > >> > > > > > > >> > > V> > >> > > > > >> > > > > > > >> > > > > > > record, SerializedKeyValue > >> > > > > serializedKeyValue); > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > ConsumerInterceptor: > >> > > > > >> > > > > > > >> > > > > > > SerializedKeyValue > >> > > onReceive(TopicPartition > >> > > > > tp, > >> > > > > >> > > > > > > >> > SerializedKeyValue > >> > > > > >> > > > > > > >> > > > > > > serializedKeyValue); > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > I am leaning towards implementing > >> the > >> > > > minimal > >> > > > > >> set > >> > > > > >> > of > >> > > > > >> > > > > > > >> immutable or > >> > > > > >> > > > > > > >> > > > > mutable > >> > > > > >> > > > > > > >> > > > > > > interfaces, making sure that we > >> have a > >> > > > > >> > compatibility > >> > > > > >> > > > > plan > >> > > > > >> > > > > > > that > >> > > > > >> > > > > > > >> > > allows > >> > > > > >> > > > > > > >> > > > > us > >> > > > > >> > > > > > > >> > > > > > to > >> > > > > >> > > > > > > >> > > > > > > add more callbacks in the future > >> (per > >> > > > Ismael > >> > > > > >> > > comment), > >> > > > > >> > > > > and > >> > > > > >> > > > > > > add > >> > > > > >> > > > > > > >> > more > >> > > > > >> > > > > > > >> > > > > APIs > >> > > > > >> > > > > > > >> > > > > > > later. E.g., for encryption > >> use-case, > >> > > there > >> > > > > >> could > >> > > > > >> > be > >> > > > > >> > > > an > >> > > > > >> > > > > > > >> argument > >> > > > > >> > > > > > > >> > in > >> > > > > >> > > > > > > >> > > > > doing > >> > > > > >> > > > > > > >> > > > > > > encryption after message > compression > >> > vs. > >> > > > > >> > per-record > >> > > > > >> > > > > > > encryption > >> > > > > >> > > > > > > >> > that > >> > > > > >> > > > > > > >> > > > > could > >> > > > > >> > > > > > > >> > > > > > > be done using the above additional > >> API. > >> > > > There > >> > > > > >> is > >> > > > > >> > > also > >> > > > > >> > > > > more > >> > > > > >> > > > > > > >> > > > implications > >> > > > > >> > > > > > > >> > > > > > for > >> > > > > >> > > > > > > >> > > > > > > every API that modifies records: > >> > > modifying > >> > > > > >> > > serialized > >> > > > > >> > > > > > > >> key/value > >> > > > > >> > > > > > > >> > > will > >> > > > > >> > > > > > > >> > > > > > again > >> > > > > >> > > > > > > >> > > > > > > impact partition assignment (we > will > >> > > likely > >> > > > > do > >> > > > > >> > that > >> > > > > >> > > > > after > >> > > > > >> > > > > > > >> > partition > >> > > > > >> > > > > > > >> > > > > > > assignment), which may impact log > >> > > > compaction > >> > > > > >> and > >> > > > > >> > > > mirror > >> > > > > >> > > > > > > maker > >> > > > > >> > > > > > > >> > > > > > partitioning. > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > Anna > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > On Tue, Jan 26, 2016 at 7:26 AM, > >> Todd > >> > > > Palino > >> > > > > < > >> > > > > >> > > > > > > >> tpal...@gmail.com> > >> > > > > >> > > > > > > >> > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > Finally got a chance to take a > >> look > >> > at > >> > > > > this. > >> > > > > >> I > >> > > > > >> > > won’t > >> > > > > >> > > > > be > >> > > > > >> > > > > > > >> able to > >> > > > > >> > > > > > > >> > > > make > >> > > > > >> > > > > > > >> > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > KIP meeting due to a conflict. > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > I’m somewhat disappointed in > this > >> > > > > proposal. I > >> > > > > >> > > think > >> > > > > >> > > > > that > >> > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > explicit > >> > > > > >> > > > > > > >> > > > > > > > exclusion of modification of the > >> > > messages > >> > > > > is > >> > > > > >> > > > > > > short-sighted, > >> > > > > >> > > > > > > >> and > >> > > > > >> > > > > > > >> > > not > >> > > > > >> > > > > > > >> > > > > > > > accounting for it now is going > to > >> > bite > >> > > us > >> > > > > >> later. > >> > > > > >> > > > Jay, > >> > > > > >> > > > > > > aren’t > >> > > > > >> > > > > > > >> > you > >> > > > > >> > > > > > > >> > > > the > >> > > > > >> > > > > > > >> > > > > > one > >> > > > > >> > > > > > > >> > > > > > > > railing against public > interfaces > >> and > >> > > how > >> > > > > >> > > difficult > >> > > > > >> > > > > they > >> > > > > >> > > > > > > >> are to > >> > > > > >> > > > > > > >> > > > work > >> > > > > >> > > > > > > >> > > > > > with > >> > > > > >> > > > > > > >> > > > > > > > when you don’t get them right? > The > >> > > > “simple” > >> > > > > >> > change > >> > > > > >> > > > to > >> > > > > >> > > > > > one > >> > > > > >> > > > > > > of > >> > > > > >> > > > > > > >> > > these > >> > > > > >> > > > > > > >> > > > > > > > interfaces to make it able to > >> return > >> > a > >> > > > > >> record is > >> > > > > >> > > > going > >> > > > > >> > > > > > to > >> > > > > >> > > > > > > >> be a > >> > > > > >> > > > > > > >> > > > > > > significant > >> > > > > >> > > > > > > >> > > > > > > > change and is going to require > all > >> > > > clients > >> > > > > to > >> > > > > >> > > > rewrite > >> > > > > >> > > > > > > their > >> > > > > >> > > > > > > >> > > > > > interceptors. > >> > > > > >> > > > > > > >> > > > > > > > If we’re not willing to put the > >> time > >> > to > >> > > > > think > >> > > > > >> > > > through > >> > > > > >> > > > > > > >> > > manipulation > >> > > > > >> > > > > > > >> > > > > now, > >> > > > > >> > > > > > > >> > > > > > > > then this KIP should be shelved > >> until > >> > > we > >> > > > > are. > >> > > > > >> > > > > > Implementing > >> > > > > >> > > > > > > >> > > > something > >> > > > > >> > > > > > > >> > > > > > > > halfway is going to be worse > than > >> > > taking > >> > > > a > >> > > > > >> > little > >> > > > > >> > > > > > longer. > >> > > > > >> > > > > > > In > >> > > > > >> > > > > > > >> > > > > addition, > >> > > > > >> > > > > > > >> > > > > > I > >> > > > > >> > > > > > > >> > > > > > > > don’t believe that manipulation > >> > > requires > >> > > > > >> > anything > >> > > > > >> > > > more > >> > > > > >> > > > > > > than > >> > > > > >> > > > > > > >> > > > > > interceptors > >> > > > > >> > > > > > > >> > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > receive the full record, and > then > >> to > >> > > > return > >> > > > > >> it. > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > There are 3 use case I can think > >> of > >> > > right > >> > > > > now > >> > > > > >> > > > without > >> > > > > >> > > > > > any > >> > > > > >> > > > > > > >> deep > >> > > > > >> > > > > > > >> > > > > > discussion > >> > > > > >> > > > > > > >> > > > > > > > that can make use of > interceptors > >> > with > >> > > > > >> > > modification: > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > 1. Auditing. The ability to add > >> > > metadata > >> > > > > to a > >> > > > > >> > > > message > >> > > > > >> > > > > > for > >> > > > > >> > > > > > > >> > > auditing > >> > > > > >> > > > > > > >> > > > is > >> > > > > >> > > > > > > >> > > > > > > > critical. Hostname, service > name, > >> > > > > timestamps, > >> > > > > >> > etc. > >> > > > > >> > > > are > >> > > > > >> > > > > > all > >> > > > > >> > > > > > > >> > pieces > >> > > > > >> > > > > > > >> > > > of > >> > > > > >> > > > > > > >> > > > > > data > >> > > > > >> > > > > > > >> > > > > > > > that can be used on the other > >> side of > >> > > the > >> > > > > >> > pipeline > >> > > > > >> > > > to > >> > > > > >> > > > > > > >> > categorize > >> > > > > >> > > > > > > >> > > > > > > messages, > >> > > > > >> > > > > > > >> > > > > > > > determine loss and transport > time, > >> > and > >> > > > pin > >> > > > > >> down > >> > > > > >> > > > > issues. > >> > > > > >> > > > > > > You > >> > > > > >> > > > > > > >> may > >> > > > > >> > > > > > > >> > > say > >> > > > > >> > > > > > > >> > > > > > that > >> > > > > >> > > > > > > >> > > > > > > > these things can just be part of > >> the > >> > > > > message > >> > > > > >> > > schema, > >> > > > > >> > > > > but > >> > > > > >> > > > > > > >> anyone > >> > > > > >> > > > > > > >> > > who > >> > > > > >> > > > > > > >> > > > > has > >> > > > > >> > > > > > > >> > > > > > > > worked with a multi-user data > >> system > >> > > > > >> (especially > >> > > > > >> > > > those > >> > > > > >> > > > > > who > >> > > > > >> > > > > > > >> have > >> > > > > >> > > > > > > >> > > > been > >> > > > > >> > > > > > > >> > > > > > > > involved with LinkedIn) know how > >> > > > difficult > >> > > > > >> it is > >> > > > > >> > > to > >> > > > > >> > > > > > > maintain > >> > > > > >> > > > > > > >> > > > > consistent > >> > > > > >> > > > > > > >> > > > > > > > message schemas and to get other > >> > people > >> > > > to > >> > > > > >> put > >> > > > > >> > in > >> > > > > >> > > > > fields > >> > > > > >> > > > > > > for > >> > > > > >> > > > > > > >> > your > >> > > > > >> > > > > > > >> > > > > use. > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > 2. Encryption. This is probably > >> the > >> > > most > >> > > > > >> obvious > >> > > > > >> > > > case > >> > > > > >> > > > > > for > >> > > > > >> > > > > > > >> > record > >> > > > > >> > > > > > > >> > > > > > > > manipulation on both sides. The > >> > ability > >> > > > to > >> > > > > >> tie > >> > > > > >> > in > >> > > > > >> > > > end > >> > > > > >> > > > > to > >> > > > > >> > > > > > > end > >> > > > > >> > > > > > > >> > > > > encryption > >> > > > > >> > > > > > > >> > > > > > > is > >> > > > > >> > > > > > > >> > > > > > > > important for data that requires > >> > > external > >> > > > > >> > > compliance > >> > > > > >> > > > > > (PCI, > >> > > > > >> > > > > > > >> > HIPAA, > >> > > > > >> > > > > > > >> > > > > > etc.). > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > 3. Routing. By being able to > add a > >> > bit > >> > > of > >> > > > > >> > > > information > >> > > > > >> > > > > > > about > >> > > > > >> > > > > > > >> the > >> > > > > >> > > > > > > >> > > > > source > >> > > > > >> > > > > > > >> > > > > > or > >> > > > > >> > > > > > > >> > > > > > > > destination of a message to the > >> > > metadata, > >> > > > > you > >> > > > > >> > can > >> > > > > >> > > > > easily > >> > > > > >> > > > > > > >> > > construct > >> > > > > >> > > > > > > >> > > > an > >> > > > > >> > > > > > > >> > > > > > > > intelligent mirror maker that > can > >> > > prevent > >> > > > > >> loops. > >> > > > > >> > > > This > >> > > > > >> > > > > > has > >> > > > > >> > > > > > > >> the > >> > > > > >> > > > > > > >> > > > > > opportunity > >> > > > > >> > > > > > > >> > > > > > > > to result in significant > >> operational > >> > > > > >> savings, as > >> > > > > >> > > you > >> > > > > >> > > > > can > >> > > > > >> > > > > > > get > >> > > > > >> > > > > > > >> > rid > >> > > > > >> > > > > > > >> > > of > >> > > > > >> > > > > > > >> > > > > the > >> > > > > >> > > > > > > >> > > > > > > > need for tiered clusters in > order > >> to > >> > > > > prevent > >> > > > > >> > loops > >> > > > > >> > > > in > >> > > > > >> > > > > > > >> mirroring > >> > > > > >> > > > > > > >> > > > > > messages. > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > All three of these share the > >> feature > >> > > that > >> > > > > >> they > >> > > > > >> > add > >> > > > > >> > > > > > > metadata > >> > > > > >> > > > > > > >> to > >> > > > > >> > > > > > > >> > > > > > messages. > >> > > > > >> > > > > > > >> > > > > > > > With the pushback on having > >> arbitrary > >> > > > > >> metadata > >> > > > > >> > as > >> > > > > >> > > an > >> > > > > >> > > > > > > >> “envelope” > >> > > > > >> > > > > > > >> > > to > >> > > > > >> > > > > > > >> > > > > the > >> > > > > >> > > > > > > >> > > > > > > > message, this is a way to > provide > >> it > >> > > and > >> > > > > >> make it > >> > > > > >> > > the > >> > > > > >> > > > > > > >> > > responsibility > >> > > > > >> > > > > > > >> > > > > of > >> > > > > >> > > > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > client, and not the Kafka broker > >> and > >> > > > system > >> > > > > >> > > itself. > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > -Todd > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > On Tue, Jan 26, 2016 at 2:30 AM, > >> > Ismael > >> > > > > Juma > >> > > > > >> < > >> > > > > >> > > > > > > >> > ism...@juma.me.uk> > >> > > > > >> > > > > > > >> > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > Hi Anna and Neha, > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > I think it makes a lot of > sense > >> to > >> > > try > >> > > > > and > >> > > > > >> > keep > >> > > > > >> > > > the > >> > > > > >> > > > > > > >> interface > >> > > > > >> > > > > > > >> > > > lean > >> > > > > >> > > > > > > >> > > > > > and > >> > > > > >> > > > > > > >> > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > > add more methods later when/if > >> > there > >> > > > is a > >> > > > > >> > need. > >> > > > > >> > > > What > >> > > > > >> > > > > > is > >> > > > > >> > > > > > > >> the > >> > > > > >> > > > > > > >> > > > current > >> > > > > >> > > > > > > >> > > > > > > > > thinking with regards to > >> > > compatibility > >> > > > > >> when/if > >> > > > > >> > > we > >> > > > > >> > > > > add > >> > > > > >> > > > > > > new > >> > > > > >> > > > > > > >> > > > methods? > >> > > > > >> > > > > > > >> > > > > A > >> > > > > >> > > > > > > >> > > > > > > few > >> > > > > >> > > > > > > >> > > > > > > > > options come to mind: > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > 1. Change the interface to an > >> > > abstract > >> > > > > >> class > >> > > > > >> > > with > >> > > > > >> > > > > > empty > >> > > > > >> > > > > > > >> > > > > > implementations > >> > > > > >> > > > > > > >> > > > > > > > for > >> > > > > >> > > > > > > >> > > > > > > > > all the methods. This means > that > >> > the > >> > > > path > >> > > > > >> to > >> > > > > >> > > > adding > >> > > > > >> > > > > > new > >> > > > > >> > > > > > > >> > methods > >> > > > > >> > > > > > > >> > > > is > >> > > > > >> > > > > > > >> > > > > > > clear. > >> > > > > >> > > > > > > >> > > > > > > > > 2. Hope we have moved to Java > 8 > >> by > >> > > the > >> > > > > >> time we > >> > > > > >> > > > need > >> > > > > >> > > > > to > >> > > > > >> > > > > > > add > >> > > > > >> > > > > > > >> > new > >> > > > > >> > > > > > > >> > > > > > methods > >> > > > > >> > > > > > > >> > > > > > > > and > >> > > > > >> > > > > > > >> > > > > > > > > use default methods with an > >> empty > >> > > > > >> > implementation > >> > > > > >> > > > for > >> > > > > >> > > > > > any > >> > > > > >> > > > > > > >> new > >> > > > > >> > > > > > > >> > > > method > >> > > > > >> > > > > > > >> > > > > > > (and > >> > > > > >> > > > > > > >> > > > > > > > > potentially make existing > >> methods > >> > > > default > >> > > > > >> > > methods > >> > > > > >> > > > > too > >> > > > > >> > > > > > at > >> > > > > >> > > > > > > >> that > >> > > > > >> > > > > > > >> > > > point > >> > > > > >> > > > > > > >> > > > > > for > >> > > > > >> > > > > > > >> > > > > > > > > consistency) > >> > > > > >> > > > > > > >> > > > > > > > > 3. Introduce a new interface > >> that > >> > > > > inherits > >> > > > > >> > from > >> > > > > >> > > > the > >> > > > > >> > > > > > > >> existing > >> > > > > >> > > > > > > >> > > > > > > Interceptor > >> > > > > >> > > > > > > >> > > > > > > > > interface when we need to add > >> new > >> > > > > methods. > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > Option 1 is the easiest and it > >> also > >> > > > means > >> > > > > >> that > >> > > > > >> > > > > > > interceptor > >> > > > > >> > > > > > > >> > > users > >> > > > > >> > > > > > > >> > > > > only > >> > > > > >> > > > > > > >> > > > > > > > need > >> > > > > >> > > > > > > >> > > > > > > > > to override the methods that > >> they > >> > are > >> > > > > >> > interested > >> > > > > >> > > > > (more > >> > > > > >> > > > > > > >> useful > >> > > > > >> > > > > > > >> > > if > >> > > > > >> > > > > > > >> > > > > the > >> > > > > >> > > > > > > >> > > > > > > > number > >> > > > > >> > > > > > > >> > > > > > > > > of methods grows). The > downside > >> is > >> > > that > >> > > > > >> > > > interceptor > >> > > > > >> > > > > > > >> > > > implementations > >> > > > > >> > > > > > > >> > > > > > > > cannot > >> > > > > >> > > > > > > >> > > > > > > > > inherit from another class (a > >> > > > > >> straightforward > >> > > > > >> > > > > > workaround > >> > > > > >> > > > > > > >> is > >> > > > > >> > > > > > > >> > to > >> > > > > >> > > > > > > >> > > > make > >> > > > > >> > > > > > > >> > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > interceptor a forwarder that > >> calls > >> > > > > another > >> > > > > >> > > class). > >> > > > > >> > > > > > Also, > >> > > > > >> > > > > > > >> our > >> > > > > >> > > > > > > >> > > > > existing > >> > > > > >> > > > > > > >> > > > > > > > > callbacks are interfaces, so > >> seems > >> > a > >> > > > bit > >> > > > > >> > > > > inconsistent. > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > Option 2 may be the most > >> appealing > >> > > one > >> > > > as > >> > > > > >> both > >> > > > > >> > > > users > >> > > > > >> > > > > > and > >> > > > > >> > > > > > > >> > > > ourselves > >> > > > > >> > > > > > > >> > > > > > > retain > >> > > > > >> > > > > > > >> > > > > > > > > flexibility. The main downside > >> is > >> > > that > >> > > > it > >> > > > > >> > relies > >> > > > > >> > > > on > >> > > > > >> > > > > us > >> > > > > >> > > > > > > >> moving > >> > > > > >> > > > > > > >> > > to > >> > > > > >> > > > > > > >> > > > > Java > >> > > > > >> > > > > > > >> > > > > > > 8, > >> > > > > >> > > > > > > >> > > > > > > > > which may be more than a year > >> away > >> > > > > >> potentially > >> > > > > >> > > (if > >> > > > > >> > > > > we > >> > > > > >> > > > > > > >> support > >> > > > > >> > > > > > > >> > > the > >> > > > > >> > > > > > > >> > > > > > last > >> > > > > >> > > > > > > >> > > > > > > 2 > >> > > > > >> > > > > > > >> > > > > > > > > Java releases). > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > Thoughts? > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > Ismael > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > On Tue, Jan 26, 2016 at 4:59 > AM, > >> > Neha > >> > > > > >> > Narkhede < > >> > > > > >> > > > > > > >> > > > n...@confluent.io> > >> > > > > >> > > > > > > >> > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > Anna, > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > I'm also in favor of > including > >> > just > >> > > > the > >> > > > > >> APIs > >> > > > > >> > > for > >> > > > > >> > > > > > which > >> > > > > >> > > > > > > >> we > >> > > > > >> > > > > > > >> > > have > >> > > > > >> > > > > > > >> > > > a > >> > > > > >> > > > > > > >> > > > > > > clear > >> > > > > >> > > > > > > >> > > > > > > > > use > >> > > > > >> > > > > > > >> > > > > > > > > > case. If more use cases for > >> finer > >> > > > > >> monitoring > >> > > > > >> > > > show > >> > > > > >> > > > > up > >> > > > > >> > > > > > > in > >> > > > > >> > > > > > > >> the > >> > > > > >> > > > > > > >> > > > > future, > >> > > > > >> > > > > > > >> > > > > > > we > >> > > > > >> > > > > > > >> > > > > > > > > can > >> > > > > >> > > > > > > >> > > > > > > > > > always update the interface. > >> > Would > >> > > > you > >> > > > > >> > please > >> > > > > >> > > > > > > highlight > >> > > > > >> > > > > > > >> in > >> > > > > >> > > > > > > >> > > the > >> > > > > >> > > > > > > >> > > > > KIP > >> > > > > >> > > > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > APIs > >> > > > > >> > > > > > > >> > > > > > > > > > that you think we have an > >> > immediate > >> > > > use > >> > > > > >> for? > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > Joel, > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > Broker-side monitoring > makes a > >> > lot > >> > > of > >> > > > > >> sense > >> > > > > >> > in > >> > > > > >> > > > the > >> > > > > >> > > > > > > long > >> > > > > >> > > > > > > >> > term > >> > > > > >> > > > > > > >> > > > > > though I > >> > > > > >> > > > > > > >> > > > > > > > > don't > >> > > > > >> > > > > > > >> > > > > > > > > > think it is a requirement > for > >> > > > > end-to-end > >> > > > > >> > > > > monitoring. > >> > > > > >> > > > > > > >> With > >> > > > > >> > > > > > > >> > the > >> > > > > >> > > > > > > >> > > > > > > producer > >> > > > > >> > > > > > > >> > > > > > > > > and > >> > > > > >> > > > > > > >> > > > > > > > > > consumer interceptors, you > >> have > >> > the > >> > > > > >> ability > >> > > > > >> > to > >> > > > > >> > > > get > >> > > > > >> > > > > > > full > >> > > > > >> > > > > > > >> > > > > > > > > > publish-to-subscribe > >> end-to-end > >> > > > > >> monitoring. > >> > > > > >> > > The > >> > > > > >> > > > > > broker > >> > > > > >> > > > > > > >> > > > > interceptor > >> > > > > >> > > > > > > >> > > > > > > > > > certainly improves the > >> resolution > >> > > of > >> > > > > >> > > monitoring > >> > > > > >> > > > > but > >> > > > > >> > > > > > it > >> > > > > >> > > > > > > >> is > >> > > > > >> > > > > > > >> > > also > >> > > > > >> > > > > > > >> > > > a > >> > > > > >> > > > > > > >> > > > > > > > riskier > >> > > > > >> > > > > > > >> > > > > > > > > > change. I prefer an > >> incremental > >> > > > > approach > >> > > > > >> > over > >> > > > > >> > > a > >> > > > > >> > > > > > > big-bang > >> > > > > >> > > > > > > >> > and > >> > > > > >> > > > > > > >> > > > > > > recommend > >> > > > > >> > > > > > > >> > > > > > > > > > taking baby-steps. Let's > first > >> > make > >> > > > > sure > >> > > > > >> the > >> > > > > >> > > > > > > >> > > producer/consumer > >> > > > > >> > > > > > > >> > > > > > > > > interceptors > >> > > > > >> > > > > > > >> > > > > > > > > > are successful. And then > come > >> > back > >> > > > and > >> > > > > >> add > >> > > > > >> > the > >> > > > > >> > > > > > broker > >> > > > > >> > > > > > > >> > > > interceptor > >> > > > > >> > > > > > > >> > > > > > > > > > carefully. > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > Having said that, it would > be > >> > great > >> > > > to > >> > > > > >> > > > understand > >> > > > > >> > > > > > your > >> > > > > >> > > > > > > >> > > proposal > >> > > > > >> > > > > > > >> > > > > for > >> > > > > >> > > > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > broker interceptor > >> independently. > >> > > We > >> > > > > can > >> > > > > >> > > either > >> > > > > >> > > > > add > >> > > > > >> > > > > > an > >> > > > > >> > > > > > > >> > > > > interceptor > >> > > > > >> > > > > > > >> > > > > > > > > > on-append or on-commit. If > >> people > >> > > > want > >> > > > > to > >> > > > > >> > use > >> > > > > >> > > > this > >> > > > > >> > > > > > for > >> > > > > >> > > > > > > >> > > > > monitoring, > >> > > > > >> > > > > > > >> > > > > > > then > >> > > > > >> > > > > > > >> > > > > > > > > > possibly on-commit might be > >> more > >> > > > > useful? > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > Neha > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > On Mon, Jan 25, 2016 at 6:47 > >> PM, > >> > > Jay > >> > > > > >> Kreps < > >> > > > > >> > > > > > > >> > j...@confluent.io > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > Hey Joel, > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > What is the interface you > >> are > >> > > > > thinking > >> > > > > >> of? > >> > > > > >> > > > > > Something > >> > > > > >> > > > > > > >> like > >> > > > > >> > > > > > > >> > > > this: > >> > > > > >> > > > > > > >> > > > > > > > > > > onAppend(String topic, > >> int > >> > > > > >> partition, > >> > > > > >> > > > > Records > >> > > > > >> > > > > > > >> > records, > >> > > > > >> > > > > > > >> > > > long > >> > > > > >> > > > > > > >> > > > > > > time) > >> > > > > >> > > > > > > >> > > > > > > > > > > ? > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > One challenge right now is > >> that > >> > > we > >> > > > > are > >> > > > > >> > still > >> > > > > >> > > > > using > >> > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > old > >> > > > > >> > > > > > > >> > > > > > > > > > > Message/MessageSet classes > >> on > >> > the > >> > > > > >> broker > >> > > > > >> > > which > >> > > > > >> > > > > I'm > >> > > > > >> > > > > > > not > >> > > > > >> > > > > > > >> > sure > >> > > > > >> > > > > > > >> > > > if > >> > > > > >> > > > > > > >> > > > > > we'd > >> > > > > >> > > > > > > >> > > > > > > > > want > >> > > > > >> > > > > > > >> > > > > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > > > > support over the long haul > >> but > >> > it > >> > > > > >> might be > >> > > > > >> > > > okay > >> > > > > >> > > > > > just > >> > > > > >> > > > > > > >> to > >> > > > > >> > > > > > > >> > > > create > >> > > > > >> > > > > > > >> > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > records > >> > > > > >> > > > > > > >> > > > > > > > > > > instance for this > interface. > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > -Jay > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > On Mon, Jan 25, 2016 at > >> 12:37 > >> > PM, > >> > > > > Joel > >> > > > > >> > > Koshy < > >> > > > > >> > > > > > > >> > > > > > jjkosh...@gmail.com> > >> > > > > >> > > > > > > >> > > > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > I'm definitely in favor > of > >> > > having > >> > > > > >> such > >> > > > > >> > > hooks > >> > > > > >> > > > > in > >> > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > produce/consume > >> > > > > >> > > > > > > >> > > > > > > > > > > > life-cycle. Not sure if > >> > people > >> > > > > >> remember > >> > > > > >> > > this > >> > > > > >> > > > > but > >> > > > > >> > > > > > > in > >> > > > > >> > > > > > > >> > Kafka > >> > > > > >> > > > > > > >> > > > 0.7 > >> > > > > >> > > > > > > >> > > > > > > this > >> > > > > >> > > > > > > >> > > > > > > > > was > >> > > > > >> > > > > > > >> > > > > > > > > > > > pretty much how it was: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > >> > > > > >> > > > >> > > > > >> > > >> > > > > >> > >> > > > > > >> > > > > >> > > > >> > > >> > https://github.com/apache/kafka/blob/0.7/core/src/main/scala/kafka/producer/async/CallbackHandler.scala > >> > > > > >> > > > > > > >> > > > > > > > > > > > i.e., we had something > >> > similar > >> > > to > >> > > > > the > >> > > > > >> > > > > > interceptor > >> > > > > >> > > > > > > >> > > proposal > >> > > > > >> > > > > > > >> > > > > for > >> > > > > >> > > > > > > >> > > > > > > > > various > >> > > > > >> > > > > > > >> > > > > > > > > > > > stages of the producer > >> > request. > >> > > > The > >> > > > > >> > > producer > >> > > > > >> > > > > > > >> provided > >> > > > > >> > > > > > > >> > > > > > call-backs > >> > > > > >> > > > > > > >> > > > > > > > for > >> > > > > >> > > > > > > >> > > > > > > > > > > > beforeEnqueue, > >> afterEnqueue, > >> > > > > >> > > afterDequeuing, > >> > > > > >> > > > > > > >> > > beforeSending, > >> > > > > >> > > > > > > >> > > > > > etc. > >> > > > > >> > > > > > > >> > > > > > > So > >> > > > > >> > > > > > > >> > > > > > > > > at > >> > > > > >> > > > > > > >> > > > > > > > > > > > LinkedIn we in fact did > >> > > auditing > >> > > > > >> within > >> > > > > >> > > > these > >> > > > > >> > > > > > > >> > call-backs > >> > > > > >> > > > > > > >> > > > (and > >> > > > > >> > > > > > > >> > > > > > not > >> > > > > >> > > > > > > >> > > > > > > > > > > > explicitly in the > >> wrapper). > >> > > Over > >> > > > > time > >> > > > > >> > and > >> > > > > >> > > > with > >> > > > > >> > > > > > 0.8 > >> > > > > >> > > > > > > >> we > >> > > > > >> > > > > > > >> > > moved > >> > > > > >> > > > > > > >> > > > > > that > >> > > > > >> > > > > > > >> > > > > > > > out > >> > > > > >> > > > > > > >> > > > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > > > wrapper libraries. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > On a side-note while > audit > >> > and > >> > > > > other > >> > > > > >> > > > > monitoring > >> > > > > >> > > > > > > can > >> > > > > >> > > > > > > >> be > >> > > > > >> > > > > > > >> > > done > >> > > > > >> > > > > > > >> > > > > > > > > internally > >> > > > > >> > > > > > > >> > > > > > > > > > > in a > >> > > > > >> > > > > > > >> > > > > > > > > > > > convenient way I think > it > >> > > should > >> > > > be > >> > > > > >> > > > clarified > >> > > > > >> > > > > > that > >> > > > > >> > > > > > > >> > > having a > >> > > > > >> > > > > > > >> > > > > > > wrapper > >> > > > > >> > > > > > > >> > > > > > > > > is > >> > > > > >> > > > > > > >> > > > > > > > > > in > >> > > > > >> > > > > > > >> > > > > > > > > > > > general not a bad idea > >> and I > >> > > > would > >> > > > > >> even > >> > > > > >> > > > > consider > >> > > > > >> > > > > > > it > >> > > > > >> > > > > > > >> to > >> > > > > >> > > > > > > >> > > be a > >> > > > > >> > > > > > > >> > > > > > > > > > > best-practice. > >> > > > > >> > > > > > > >> > > > > > > > > > > > Even with 0.7 we still > >> had a > >> > > > > wrapper > >> > > > > >> > > library > >> > > > > >> > > > > and > >> > > > > >> > > > > > > >> that > >> > > > > >> > > > > > > >> > API > >> > > > > >> > > > > > > >> > > > has > >> > > > > >> > > > > > > >> > > > > > > > largely > >> > > > > >> > > > > > > >> > > > > > > > > > > > stayed the same and has > >> > helped > >> > > > > >> protect > >> > > > > >> > > > against > >> > > > > >> > > > > > > >> > (sometimes > >> > > > > >> > > > > > > >> > > > > > > backwards > >> > > > > >> > > > > > > >> > > > > > > > > > > > incompatible) changes in > >> open > >> > > > > source. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > While we are on this > >> topic I > >> > > have > >> > > > > one > >> > > > > >> > > > comment > >> > > > > >> > > > > > and > >> > > > > >> > > > > > > >> Anna, > >> > > > > >> > > > > > > >> > > you > >> > > > > >> > > > > > > >> > > > > may > >> > > > > >> > > > > > > >> > > > > > > > have > >> > > > > >> > > > > > > >> > > > > > > > > > > > already considered this > >> but I > >> > > > don't > >> > > > > >> see > >> > > > > >> > > > > mention > >> > > > > >> > > > > > of > >> > > > > >> > > > > > > >> it > >> > > > > >> > > > > > > >> > in > >> > > > > >> > > > > > > >> > > > the > >> > > > > >> > > > > > > >> > > > > > KIP: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > Add a custom message > >> > > > > >> > interceptor/validator > >> > > > > >> > > > on > >> > > > > >> > > > > > the > >> > > > > >> > > > > > > >> > broker > >> > > > > >> > > > > > > >> > > on > >> > > > > >> > > > > > > >> > > > > > > message > >> > > > > >> > > > > > > >> > > > > > > > > > > > arrival. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > We decompress and do > basic > >> > > > > >> validation of > >> > > > > >> > > > > > messages > >> > > > > >> > > > > > > on > >> > > > > >> > > > > > > >> > > > > arrival. I > >> > > > > >> > > > > > > >> > > > > > > > think > >> > > > > >> > > > > > > >> > > > > > > > > > > there > >> > > > > >> > > > > > > >> > > > > > > > > > > > is value in supporting > >> custom > >> > > > > >> validation > >> > > > > >> > > and > >> > > > > >> > > > > > > expand > >> > > > > >> > > > > > > >> it > >> > > > > >> > > > > > > >> > to > >> > > > > >> > > > > > > >> > > > > > support > >> > > > > >> > > > > > > >> > > > > > > > > > custom > >> > > > > >> > > > > > > >> > > > > > > > > > > > on-arrival processing. > >> Here > >> > is > >> > > a > >> > > > > >> > specific > >> > > > > >> > > > > > > use-case I > >> > > > > >> > > > > > > >> > have > >> > > > > >> > > > > > > >> > > > in > >> > > > > >> > > > > > > >> > > > > > > mind. > >> > > > > >> > > > > > > >> > > > > > > > > The > >> > > > > >> > > > > > > >> > > > > > > > > > > blog > >> > > > > >> > > > > > > >> > > > > > > > > > > > that James referenced > >> > describes > >> > > > our > >> > > > > >> > > auditing > >> > > > > >> > > > > > > >> > > > infrastructure. > >> > > > > >> > > > > > > >> > > > > In > >> > > > > >> > > > > > > >> > > > > > > > order > >> > > > > >> > > > > > > >> > > > > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > > > > > audit the Kafka cluster > >> > itself > >> > > we > >> > > > > >> need > >> > > > > >> > to > >> > > > > >> > > > run > >> > > > > >> > > > > a > >> > > > > >> > > > > > > >> > "console > >> > > > > >> > > > > > > >> > > > > > auditor" > >> > > > > >> > > > > > > >> > > > > > > > > > service > >> > > > > >> > > > > > > >> > > > > > > > > > > > that consumes everything > >> and > >> > > > spits > >> > > > > >> out > >> > > > > >> > > audit > >> > > > > >> > > > > > > events > >> > > > > >> > > > > > > >> > back > >> > > > > >> > > > > > > >> > > to > >> > > > > >> > > > > > > >> > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > cluster. > >> > > > > >> > > > > > > >> > > > > > > > > > > I > >> > > > > >> > > > > > > >> > > > > > > > > > > > would prefer not having > to > >> > run > >> > > > this > >> > > > > >> > > service > >> > > > > >> > > > > > > because: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > - Well, it is one > more > >> > > service > >> > > > > >> that > >> > > > > >> > we > >> > > > > >> > > > have > >> > > > > >> > > > > > to > >> > > > > >> > > > > > > >> run > >> > > > > >> > > > > > > >> > and > >> > > > > >> > > > > > > >> > > > > > monitor > >> > > > > >> > > > > > > >> > > > > > > > > > > > - Consuming > everything > >> > takes > >> > > > up > >> > > > > >> > > bandwidth > >> > > > > >> > > > > > which > >> > > > > >> > > > > > > >> can > >> > > > > >> > > > > > > >> > be > >> > > > > >> > > > > > > >> > > > > > avoided > >> > > > > >> > > > > > > >> > > > > > > > > > > > - The console auditor > >> > > consumer > >> > > > > >> itself > >> > > > > >> > > can > >> > > > > >> > > > > lag > >> > > > > >> > > > > > > and > >> > > > > >> > > > > > > >> > > cause > >> > > > > >> > > > > > > >> > > > > > > > temporary > >> > > > > >> > > > > > > >> > > > > > > > > > > audit > >> > > > > >> > > > > > > >> > > > > > > > > > > > discrepancies > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > One way we can mitigate > >> this > >> > is > >> > > > by > >> > > > > >> > having > >> > > > > >> > > > > > > >> mirror-makers > >> > > > > >> > > > > > > >> > > in > >> > > > > >> > > > > > > >> > > > > > > between > >> > > > > >> > > > > > > >> > > > > > > > > > > clusters > >> > > > > >> > > > > > > >> > > > > > > > > > > > emit audit events. The > >> > problem > >> > > is > >> > > > > >> that > >> > > > > >> > the > >> > > > > >> > > > > very > >> > > > > >> > > > > > > last > >> > > > > >> > > > > > > >> > > > cluster > >> > > > > >> > > > > > > >> > > > > in > >> > > > > >> > > > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > > > pipeline will not have > any > >> > > audit > >> > > > > >> which > >> > > > > >> > is > >> > > > > >> > > > why > >> > > > > >> > > > > we > >> > > > > >> > > > > > > >> need > >> > > > > >> > > > > > > >> > to > >> > > > > >> > > > > > > >> > > > have > >> > > > > >> > > > > > > >> > > > > > > > > something > >> > > > > >> > > > > > > >> > > > > > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > > > > > audit the cluster. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > If we had a custom > message > >> > > > > validator > >> > > > > >> > then > >> > > > > >> > > > the > >> > > > > >> > > > > > > audit > >> > > > > >> > > > > > > >> can > >> > > > > >> > > > > > > >> > > be > >> > > > > >> > > > > > > >> > > > > done > >> > > > > >> > > > > > > >> > > > > > > > > > > on-arrival > >> > > > > >> > > > > > > >> > > > > > > > > > > > and we won't need a > >> console > >> > > > > auditor. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > One potential issue in > >> this > >> > > > > approach > >> > > > > >> and > >> > > > > >> > > any > >> > > > > >> > > > > > > >> elaborate > >> > > > > >> > > > > > > >> > > > > > on-arrival > >> > > > > >> > > > > > > >> > > > > > > > > > > > processing for that > >> matter is > >> > > > that > >> > > > > >> you > >> > > > > >> > may > >> > > > > >> > > > > need > >> > > > > >> > > > > > to > >> > > > > >> > > > > > > >> > > > > deserialize > >> > > > > >> > > > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > > message > >> > > > > >> > > > > > > >> > > > > > > > > > > > as well which can drive > up > >> > > > produce > >> > > > > >> > request > >> > > > > >> > > > > > > handling > >> > > > > >> > > > > > > >> > > times. > >> > > > > >> > > > > > > >> > > > > > > However > >> > > > > >> > > > > > > >> > > > > > > > > I'm > >> > > > > >> > > > > > > >> > > > > > > > > > > not > >> > > > > >> > > > > > > >> > > > > > > > > > > > terribly concerned about > >> that > >> > > > > >> especially > >> > > > > >> > > if > >> > > > > >> > > > > the > >> > > > > >> > > > > > > >> audit > >> > > > > >> > > > > > > >> > > > header > >> > > > > >> > > > > > > >> > > > > > can > >> > > > > >> > > > > > > >> > > > > > > be > >> > > > > >> > > > > > > >> > > > > > > > > > > > separated out easily or > >> even > >> > > > > >> > deserialized > >> > > > > >> > > > > > > partially > >> > > > > >> > > > > > > >> as > >> > > > > >> > > > > > > >> > > this > >> > > > > >> > > > > > > >> > > > > > Avro > >> > > > > >> > > > > > > >> > > > > > > > > thread > >> > > > > >> > > > > > > >> > > > > > > > > > > > touches on > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > >> > > > > >> > > > >> > > > > >> > > >> > > > > >> > >> > > > > > >> > > > > >> > > > >> > > >> > http://search-hadoop.com/m/F2svI1HDLY12W8tnH1&subj=Re+any+optimization+in+reading+a+partial+schema+in+the+decoder+ > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > Joel > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > On Mon, Jan 25, 2016 at > >> 12:02 > >> > > PM, > >> > > > > >> > Mayuresh > >> > > > > >> > > > > > Gharat > >> > > > > >> > > > > > > < > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> gharatmayures...@gmail.com> > >> > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > Nice KIP. Excellent > >> idea. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > Was just thinking if > we > >> can > >> > > add > >> > > > > >> > > onDequed() > >> > > > > >> > > > > to > >> > > > > >> > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > ProducerIterceptor > >> > > > > >> > > > > > > >> > > > > > > > > > > > > interface. Since we > have > >> > the > >> > > > > >> > > onEnqueued(), > >> > > > > >> > > > > it > >> > > > > >> > > > > > > will > >> > > > > >> > > > > > > >> > help > >> > > > > >> > > > > > > >> > > > the > >> > > > > >> > > > > > > >> > > > > > > > client > >> > > > > >> > > > > > > >> > > > > > > > > or > >> > > > > >> > > > > > > >> > > > > > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > > > > tools to know how much > >> time > >> > > the > >> > > > > >> > message > >> > > > > >> > > > > spent > >> > > > > >> > > > > > in > >> > > > > >> > > > > > > >> the > >> > > > > >> > > > > > > >> > > > > > > > > > RecordAccumulator. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > Also an API to check > if > >> > there > >> > > > are > >> > > > > >> any > >> > > > > >> > > > > messages > >> > > > > >> > > > > > > >> left > >> > > > > >> > > > > > > >> > > for a > >> > > > > >> > > > > > > >> > > > > > > > > particular > >> > > > > >> > > > > > > >> > > > > > > > > > > > topic > >> > > > > >> > > > > > > >> > > > > > > > > > > > > in the > RecordAccumulator > >> > > would > >> > > > > >> help. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > Mayuresh > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > On Mon, Jan 25, 2016 > at > >> > 11:29 > >> > > > AM, > >> > > > > >> Todd > >> > > > > >> > > > > Palino > >> > > > > >> > > > > > < > >> > > > > >> > > > > > > >> > > > > > > tpal...@gmail.com > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > Great idea. I’ve > been > >> > > talking > >> > > > > >> about > >> > > > > >> > > this > >> > > > > >> > > > > > for 2 > >> > > > > >> > > > > > > >> > years, > >> > > > > >> > > > > > > >> > > > and > >> > > > > >> > > > > > > >> > > > > > I’m > >> > > > > >> > > > > > > >> > > > > > > > > glad > >> > > > > >> > > > > > > >> > > > > > > > > > > > > someone > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > is finally picking > it > >> up. > >> > > > Will > >> > > > > >> take > >> > > > > >> > a > >> > > > > >> > > > look > >> > > > > >> > > > > > at > >> > > > > >> > > > > > > >> the > >> > > > > >> > > > > > > >> > KIP > >> > > > > >> > > > > > > >> > > > at > >> > > > > >> > > > > > > >> > > > > > some > >> > > > > >> > > > > > > >> > > > > > > > > point > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > shortly. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > -Todd > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > On Mon, Jan 25, 2016 > >> at > >> > > 11:24 > >> > > > > AM, > >> > > > > >> > Jay > >> > > > > >> > > > > Kreps > >> > > > > >> > > > > > < > >> > > > > >> > > > > > > >> > > > > > > j...@confluent.io> > >> > > > > >> > > > > > > >> > > > > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > Hey Becket, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > Yeah this is > really > >> > > similar > >> > > > > to > >> > > > > >> the > >> > > > > >> > > > > > callback. > >> > > > > >> > > > > > > >> The > >> > > > > >> > > > > > > >> > > > > > difference > >> > > > > >> > > > > > > >> > > > > > > > is > >> > > > > >> > > > > > > >> > > > > > > > > > > really > >> > > > > >> > > > > > > >> > > > > > > > > > > > > in > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > who sets the > >> behavior. > >> > > The > >> > > > > >> idea of > >> > > > > >> > > the > >> > > > > >> > > > > > > >> > interceptor > >> > > > > >> > > > > > > >> > > is > >> > > > > >> > > > > > > >> > > > > > that > >> > > > > >> > > > > > > >> > > > > > > it > >> > > > > >> > > > > > > >> > > > > > > > > > > doesn't > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > require any code > >> change > >> > > in > >> > > > > >> apps so > >> > > > > >> > > you > >> > > > > >> > > > > can > >> > > > > >> > > > > > > >> > globally > >> > > > > >> > > > > > > >> > > > add > >> > > > > >> > > > > > > >> > > > > > > > > behavior > >> > > > > >> > > > > > > >> > > > > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > > > > > > your > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > Kafka usage > without > >> > > > changing > >> > > > > >> app > >> > > > > >> > > code. > >> > > > > >> > > > > > > Whereas > >> > > > > >> > > > > > > >> > the > >> > > > > >> > > > > > > >> > > > > > callback > >> > > > > >> > > > > > > >> > > > > > > > is > >> > > > > >> > > > > > > >> > > > > > > > > > > added > >> > > > > >> > > > > > > >> > > > > > > > > > > > by > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > app. The idea is > to > >> > kind > >> > > of > >> > > > > >> > obviate > >> > > > > >> > > > the > >> > > > > >> > > > > > need > >> > > > > >> > > > > > > >> for > >> > > > > >> > > > > > > >> > > the > >> > > > > >> > > > > > > >> > > > > > > wrapper > >> > > > > >> > > > > > > >> > > > > > > > > code > >> > > > > >> > > > > > > >> > > > > > > > > > > > that > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > e.g. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > LinkedIn maintains > >> to > >> > > hold > >> > > > > this > >> > > > > >> > kind > >> > > > > >> > > > of > >> > > > > >> > > > > > > stuff. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > -Jay > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > On Sun, Jan 24, > >> 2016 at > >> > > > 4:21 > >> > > > > >> PM, > >> > > > > >> > > > Becket > >> > > > > >> > > > > > Qin > >> > > > > >> > > > > > > < > >> > > > > >> > > > > > > >> > > > > > > > > > becket....@gmail.com> > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > This could be a > >> > useful > >> > > > > >> feature. > >> > > > > >> > > And > >> > > > > >> > > > I > >> > > > > >> > > > > > > think > >> > > > > >> > > > > > > >> > there > >> > > > > >> > > > > > > >> > > > are > >> > > > > >> > > > > > > >> > > > > > > some > >> > > > > >> > > > > > > >> > > > > > > > > use > >> > > > > >> > > > > > > >> > > > > > > > > > > > cases > >> > > > > >> > > > > > > >> > > > > > > > > > > > > to > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > mutate the data > >> like > >> > > > > rejected > >> > > > > >> > > > > > alternative > >> > > > > >> > > > > > > >> one > >> > > > > >> > > > > > > >> > > > > > mentioned. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > I am wondering > if > >> > there > >> > > > is > >> > > > > >> > > > functional > >> > > > > >> > > > > > > >> > overlapping > >> > > > > >> > > > > > > >> > > > > > between > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > ProducerInterceptor.onAcknowledgement() > >> > > > > >> > > > > > > and > >> > > > > >> > > > > > > >> the > >> > > > > >> > > > > > > >> > > > > > producer > >> > > > > >> > > > > > > >> > > > > > > > > > > callback? > >> > > > > >> > > > > > > >> > > > > > > > > > > > I > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > can > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > see that the > >> Callback > >> > > > could > >> > > > > >> be a > >> > > > > >> > > per > >> > > > > >> > > > > > > record > >> > > > > >> > > > > > > >> > > setting > >> > > > > >> > > > > > > >> > > > > > while > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> onAcknowledgement() > >> > is > >> > > a > >> > > > > >> > producer > >> > > > > >> > > > > level > >> > > > > >> > > > > > > >> > setting. > >> > > > > >> > > > > > > >> > > > > Other > >> > > > > >> > > > > > > >> > > > > > > than > >> > > > > >> > > > > > > >> > > > > > > > > > that, > >> > > > > >> > > > > > > >> > > > > > > > > > > > is > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > there > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > any difference > >> > between > >> > > > > them? > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > Jiangjie > (Becket) > >> Qin > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > On Fri, Jan 22, > >> 2016 > >> > at > >> > > > > 6:21 > >> > > > > >> PM, > >> > > > > >> > > > Neha > >> > > > > >> > > > > > > >> Narkhede > >> > > > > >> > > > > > > >> > < > >> > > > > >> > > > > > > >> > > > > > > > > > > n...@confluent.io> > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > James, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > That is one of > >> the > >> > > many > >> > > > > >> > > monitoring > >> > > > > >> > > > > use > >> > > > > >> > > > > > > >> cases > >> > > > > >> > > > > > > >> > > for > >> > > > > >> > > > > > > >> > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > > interceptor > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > interface. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > Neha > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > On Fri, Jan > 22, > >> > 2016 > >> > > at > >> > > > > >> 6:18 > >> > > > > >> > PM, > >> > > > > >> > > > > James > >> > > > > >> > > > > > > >> Cheng > >> > > > > >> > > > > > > >> > < > >> > > > > >> > > > > > > >> > > > > > > > > > jch...@tivo.com> > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > Anna, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > I'm trying > to > >> > > > > understand > >> > > > > >> a > >> > > > > >> > > > > concrete > >> > > > > >> > > > > > > use > >> > > > > >> > > > > > > >> > case. > >> > > > > >> > > > > > > >> > > > It > >> > > > > >> > > > > > > >> > > > > > > sounds > >> > > > > >> > > > > > > >> > > > > > > > > > like > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > producer > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > interceptors > >> > could > >> > > be > >> > > > > >> used > >> > > > > >> > to > >> > > > > >> > > > > > > implement > >> > > > > >> > > > > > > >> > part > >> > > > > >> > > > > > > >> > > of > >> > > > > >> > > > > > > >> > > > > > > > > LinkedIn's > >> > > > > >> > > > > > > >> > > > > > > > > > > > Kafak > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > Audit > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > tool? > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > https://engineering.linkedin.com/kafka/running-kafka-scale > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > Part of that > >> is > >> > > done > >> > > > > by a > >> > > > > >> > > > wrapper > >> > > > > >> > > > > > > >> library > >> > > > > >> > > > > > > >> > > > around > >> > > > > >> > > > > > > >> > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > kafka > >> > > > > >> > > > > > > >> > > > > > > > > > > > > producer > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > that > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > keeps a > count > >> of > >> > > the > >> > > > > >> number > >> > > > > >> > of > >> > > > > >> > > > > > > messages > >> > > > > >> > > > > > > >> > > > produced, > >> > > > > >> > > > > > > >> > > > > > and > >> > > > > >> > > > > > > >> > > > > > > > > then > >> > > > > >> > > > > > > >> > > > > > > > > > > > sends > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > that > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > count > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > to a > >> side-topic. > >> > It > >> > > > > >> sounds > >> > > > > >> > > like > >> > > > > >> > > > > the > >> > > > > >> > > > > > > >> > producer > >> > > > > >> > > > > > > >> > > > > > > > interceptors > >> > > > > >> > > > > > > >> > > > > > > > > > > could > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > possibly > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > be > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > used to > >> implement > >> > > > that? > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > -James > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > On Jan 22, > >> > 2016, > >> > > at > >> > > > > >> 4:33 > >> > > > > >> > PM, > >> > > > > >> > > > > Anna > >> > > > > >> > > > > > > >> > Povzner < > >> > > > > >> > > > > > > >> > > > > > > > > > > a...@confluent.io > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > wrote: > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > Hi, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > I just > >> created > >> > a > >> > > > > KIP-42 > >> > > > > >> > for > >> > > > > >> > > > > adding > >> > > > > >> > > > > > > >> > producer > >> > > > > >> > > > > > > >> > > > and > >> > > > > >> > > > > > > >> > > > > > > > > consumer > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > interceptors > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > for > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > intercepting > >> > > > messages > >> > > > > >> at > >> > > > > >> > > > > different > >> > > > > >> > > > > > > >> points > >> > > > > >> > > > > > > >> > > on > >> > > > > >> > > > > > > >> > > > > > > producer > >> > > > > >> > > > > > > >> > > > > > > > > and > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > consumer. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > >> > > > > >> > > > >> > > > > >> > > >> > > > > >> > >> > > > > > >> > > > > >> > > > >> > > >> > https://cwiki.apache.org/confluence/display/KAFKA/KIP-42%3A+Add+Producer+and+Consumer+Interceptors > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > Comments > and > >> > > > > >> suggestions > >> > > > > >> > are > >> > > > > >> > > > > > > welcome! > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > Anna > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > ________________________________ > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > This email > and > >> > any > >> > > > > >> > attachments > >> > > > > >> > > > may > >> > > > > >> > > > > > > >> contain > >> > > > > >> > > > > > > >> > > > > > > confidential > >> > > > > >> > > > > > > >> > > > > > > > > and > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > privileged > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > material for > >> the > >> > > sole > >> > > > > >> use of > >> > > > > >> > > the > >> > > > > >> > > > > > > >> intended > >> > > > > >> > > > > > > >> > > > > > recipient. > >> > > > > >> > > > > > > >> > > > > > > > Any > >> > > > > >> > > > > > > >> > > > > > > > > > > > review, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > copying, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > or > >> distribution > >> > of > >> > > > this > >> > > > > >> > email > >> > > > > >> > > > (or > >> > > > > >> > > > > > any > >> > > > > >> > > > > > > >> > > > > attachments) > >> > > > > >> > > > > > > >> > > > > > by > >> > > > > >> > > > > > > >> > > > > > > > > > others > >> > > > > >> > > > > > > >> > > > > > > > > > > is > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > prohibited. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > If you are > not > >> > the > >> > > > > >> intended > >> > > > > >> > > > > > recipient, > >> > > > > >> > > > > > > >> > please > >> > > > > >> > > > > > > >> > > > > > contact > >> > > > > >> > > > > > > >> > > > > > > > the > >> > > > > >> > > > > > > >> > > > > > > > > > > > sender > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > immediately > >> and > >> > > > > >> permanently > >> > > > > >> > > > delete > >> > > > > >> > > > > > > this > >> > > > > >> > > > > > > >> > email > >> > > > > >> > > > > > > >> > > > and > >> > > > > >> > > > > > > >> > > > > > any > >> > > > > >> > > > > > > >> > > > > > > > > > > > > attachments. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > No > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > employee or > >> agent > >> > > of > >> > > > > TiVo > >> > > > > >> > Inc. > >> > > > > >> > > > is > >> > > > > >> > > > > > > >> > authorized > >> > > > > >> > > > > > > >> > > to > >> > > > > >> > > > > > > >> > > > > > > > conclude > >> > > > > >> > > > > > > >> > > > > > > > > > any > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > binding > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > agreement on > >> > behalf > >> > > > of > >> > > > > >> TiVo > >> > > > > >> > > Inc. > >> > > > > >> > > > > by > >> > > > > >> > > > > > > >> email. > >> > > > > >> > > > > > > >> > > > > Binding > >> > > > > >> > > > > > > >> > > > > > > > > > agreements > >> > > > > >> > > > > > > >> > > > > > > > > > > > > with > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > TiVo > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > Inc. may > only > >> be > >> > > made > >> > > > > by > >> > > > > >> a > >> > > > > >> > > > signed > >> > > > > >> > > > > > > >> written > >> > > > > >> > > > > > > >> > > > > > agreement. > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > -- > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > Neha > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > -- > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > *—-* > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > *Todd Palino* > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > Staff Site > Reliability > >> > > > Engineer > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > Data Infrastructure > >> > > Streaming > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > linkedin.com/in/toddpalino > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > -- > >> > > > > >> > > > > > > >> > > > > > > > > > > > > -Regards, > >> > > > > >> > > > > > > >> > > > > > > > > > > > > Mayuresh R. Gharat > >> > > > > >> > > > > > > >> > > > > > > > > > > > > (862) 250-7125 > >> > > > > >> > > > > > > >> > > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > -- > >> > > > > >> > > > > > > >> > > > > > > > > > Thanks, > >> > > > > >> > > > > > > >> > > > > > > > > > Neha > >> > > > > >> > > > > > > >> > > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > -- > >> > > > > >> > > > > > > >> > > > > > > > *—-* > >> > > > > >> > > > > > > >> > > > > > > > *Todd Palino* > >> > > > > >> > > > > > > >> > > > > > > > Staff Site Reliability Engineer > >> > > > > >> > > > > > > >> > > > > > > > Data Infrastructure Streaming > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > linkedin.com/in/toddpalino > >> > > > > >> > > > > > > >> > > > > > > > > >> > > > > >> > > > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > -- > >> > > > > >> > > > > > > >> > > > > > -Regards, > >> > > > > >> > > > > > > >> > > > > > Mayuresh R. Gharat > >> > > > > >> > > > > > > >> > > > > > (862) 250-7125 > >> > > > > >> > > > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > -- > >> > > > > >> > > > > > > >> > > > *—-* > >> > > > > >> > > > > > > >> > > > *Todd Palino* > >> > > > > >> > > > > > > >> > > > Staff Site Reliability Engineer > >> > > > > >> > > > > > > >> > > > Data Infrastructure Streaming > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > linkedin.com/in/toddpalino > >> > > > > >> > > > > > > >> > > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > -- > >> > > > > >> > > > > > > >> > > -Regards, > >> > > > > >> > > > > > > >> > > Mayuresh R. Gharat > >> > > > > >> > > > > > > >> > > (862) 250-7125 > >> > > > > >> > > > > > > >> > > > >> > > > > >> > > > > > > >> > > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > >> -- > >> > > > > >> > > > > > > >> -Regards, > >> > > > > >> > > > > > > >> Mayuresh R. Gharat > >> > > > > >> > > > > > > >> (862) 250-7125 > >> > > > > >> > > > > > > >> > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > > > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > > -- > >> > > > > >> > > > > > Thanks, > >> > > > > >> > > > > > Neha > >> > > > > >> > > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > >> > > > > >> > > > >> > > > > >> > > >> > > > > >> > >> > > > > >> > >> > > > > >> > >> > > > > >> -- > >> > > > > >> *—-* > >> > > > > >> *Todd Palino* > >> > > > > >> Staff Site Reliability Engineer > >> > > > > >> Data Infrastructure Streaming > >> > > > > >> > >> > > > > >> > >> > > > > >> > >> > > > > >> linkedin.com/in/toddpalino > >> > > > > >> > >> > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > >> > > > >> > > -- > >> > > Thanks, > >> > > Neha > >> > > > >> > > >> > > > > >
