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 >
