Agree that you need version in getErrorResponse too (so you'll get the correct error), which means you'll need to add versionId to constructors of every response object...
You'll want to keep two interfaces, one with version and one with CURR_VERSION as default, so you won't need to modify every single call... On Fri, May 15, 2015 at 4:03 PM, Andrii Biletskyi < andrii.bilets...@stealth.ly> wrote: > Correct, I think we are on the same page. > This way we can fix RequestChannel part (where it uses > AbstractRequest.getRequest) > > But would it be okay to add versionId to AbstractRequest.getErrorResponse > signature too? > I'm a bit lost with all those Abstract... objects hierarchy and not sure > whether it's > the right solution. > > Thanks, > Andrii Biletskyi > > On Fri, May 15, 2015 at 3:47 PM, Gwen Shapira <gshap...@cloudera.com> > wrote: > > > I agree, we currently don't handle versions correctly when de-serializing > > into java objects. This will be an isssue for every req/resp we move to > use > > the java objects. > > > > It looks like this requires: > > 1. Add versionId parameter to all parse functions in Java req/resp > objects > > 2. Modify getRequest to pass it along > > 3. Modify RequestChannel to get the version out of the header and use it > > when de-serializing the body. > > > > Did I get that correct? I want to make sure we are talking about the same > > issue. > > > > Gwen > > > > On Fri, May 15, 2015 at 1:45 PM, Andrii Biletskyi < > > andrii.bilets...@stealth.ly> wrote: > > > > > Gwen, > > > > > > I didn't find this in answers above so apologies if this was discussed. > > > It's about the way we would like to handle request versions. > > > > > > As I understood from Jun's answer we generally should try using the > same > > > java object while evolving the request. I believe the only example of > > > evolved > > > request now - OffsetCommitRequest follows this approach. > > > > > > I'm trying to evolve MetadataRequest to the next version as part of > KIP-4 > > > and not sure current AbstractRequest api (which is a basis for ported > to > > > java requests) > > > is sufficient. > > > > > > The problem is: in order to deserialize bytes into correct correct > object > > > you need > > > to know it's version. Suppose KafkaApi serves OffsetCommitRequestV0 and > > V2 > > > (current). > > > For such cases OffsetCommitRequest class has two constructors: > > > > > > public static OffsetCommitRequest parse(ByteBuffer buffer, int > versionId) > > > AND > > > public static OffsetCommitRequest parse(ByteBuffer buffer) > > > > > > The latter one will simply pick the "current" schema version. > > > Now AbstractRequest.getRequest which is an entry point for > deserializing > > > request > > > for KafkaApi matches only on RequestHeader.apiKey (and thus uses the > > second > > > OffsetCommitRequest constructor) which is not sufficient because we > also > > > need > > > RequestHeader.apiVersion in case old request version. > > > > > > The same problem appears in AbstractRequest.getErrorResponse(Throwable > > e) - > > > to construct the right error response object we need to know to which > > > apiVersion > > > to respond. > > > > > > I think this can affect other tasks under KAFKA-1927 - replacing > separate > > > RQ/RP, > > > so maybe it makes sense to decide/fix it once. > > > > > > Thanks, > > > Andrii Bieltskyi > > > > > > > > > > > > > > > > > > On Wed, Mar 25, 2015 at 12:42 AM, Gwen Shapira <gshap...@cloudera.com> > > > wrote: > > > > > > > OK, I posted a working patch on KAFKA-2044 and > > > > https://reviews.apache.org/r/32459/diff/. > > > > > > > > There are few decisions there than can be up to discussion (factory > > > method > > > > on AbstractRequestResponse, the new handleErrors in request API), but > > as > > > > far as support for o.a.k.common requests in core goes, it does what > it > > > > needs to do. > > > > > > > > Please review! > > > > > > > > Gwen > > > > > > > > > > > > > > > > On Tue, Mar 24, 2015 at 10:59 AM, Gwen Shapira < > gshap...@cloudera.com> > > > > wrote: > > > > > > > > > Hi, > > > > > > > > > > I uploaded a (very) preliminary patch with my idea. > > > > > > > > > > One thing thats missing: > > > > > RequestResponse had handleError method that all requests > > implemented, > > > > > typically generating appropriate error Response for the request and > > > > sending > > > > > it along. Its used by KafkaApis to handle all protocol errors for > > valid > > > > > requests that are not handled elsewhere. > > > > > AbstractRequestResponse doesn't have such method. > > > > > > > > > > I can, of course, add it. > > > > > But before I jump into this, I'm wondering if there was another > plan > > on > > > > > handling Api errors. > > > > > > > > > > Gwen > > > > > > > > > > On Mon, Mar 23, 2015 at 6:16 PM, Jun Rao <j...@confluent.io> wrote: > > > > > > > > > >> I think what you are saying is that in RequestChannel, we can > start > > > > >> generating header/body for new request types and leave requestObj > > > null. > > > > >> For > > > > >> existing requests, header/body will be null initially. Gradually, > we > > > can > > > > >> migrate each type of requests by populating header/body, instead > of > > > > >> requestObj. This makes sense to me since it serves two purposes > (1) > > > not > > > > >> polluting the code base with duplicated request/response objects > for > > > new > > > > >> types of requests and (2) allowing the refactoring of existing > > > requests > > > > to > > > > >> be done in smaller pieces. > > > > >> > > > > >> Could you try that approach and perhaps just migrate one existing > > > > request > > > > >> type (e.g. HeartBeatRequest) as an example? We probably need to > > rewind > > > > the > > > > >> buffer after reading the requestId when deserializing the header > > > (since > > > > >> the > > > > >> header includes the request id). > > > > >> > > > > >> Thanks, > > > > >> > > > > >> Jun > > > > >> > > > > >> On Mon, Mar 23, 2015 at 4:52 PM, Gwen Shapira < > > gshap...@cloudera.com> > > > > >> wrote: > > > > >> > > > > >> > I'm thinking of a different approach, that will not fix > > everything, > > > > but > > > > >> > will allow adding new requests without code duplication (and > > > therefore > > > > >> > unblock KIP-4): > > > > >> > > > > > >> > RequestChannel.request currently takes a buffer and parses it > into > > > an > > > > >> "old" > > > > >> > request object. Since the objects are byte-compatibly, we should > > be > > > > >> able to > > > > >> > parse existing requests into both old and new objects. New > > requests > > > > will > > > > >> > only be parsed into new objects. > > > > >> > > > > > >> > Basically: > > > > >> > val requestId = buffer.getShort() > > > > >> > if (requestId in keyToNameAndDeserializerMap) { > > > > >> > requestObj = > RequestKeys.deserializerForKey(requestId)(buffer) > > > > >> > header: RequestHeader = RequestHeader.parse(buffer) > > > > >> > body: Struct = > > > > >> > > > > > >> > > > > > > ProtoUtils.currentRequestSchema(apiKey).read(buffer).asInstanceOf[Struct] > > > > >> > } else { > > > > >> > requestObj = null > > > > >> > header: RequestHeader = RequestHeader.parse(buffer) > > > > >> > body: Struct = > > > > >> > > > > > >> > > > > > > ProtoUtils.currentRequestSchema(apiKey).read(buffer).asInstanceOf[Struct] > > > > >> > } > > > > >> > > > > > >> > This way existing KafkaApis will keep working as normal. The new > > > Apis > > > > >> can > > > > >> > implement just the new header/body requests. > > > > >> > We'll do the same on the send-side: BoundedByteBufferSend can > > have a > > > > >> > constructor that takes header/body instead of just a response > > > object. > > > > >> > > > > > >> > Does that make sense? > > > > >> > > > > > >> > Once we have this in, we can move to: > > > > >> > * Adding the missing request/response to the client code > > > > >> > * Replacing requests that can be replaced > > > > >> > > > > > >> > It will also make life easier by having us review and tests > > smaller > > > > >> chunks > > > > >> > of work (the existing patch is *huge* , touches nearly every > core > > > > >> component > > > > >> > and I'm not done yet...) > > > > >> > > > > > >> > Gwen > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > On Sun, Mar 22, 2015 at 10:24 PM, Jay Kreps < > jay.kr...@gmail.com> > > > > >> wrote: > > > > >> > > > > > >> > > Ack, yeah, forgot about that. > > > > >> > > > > > > >> > > It's not just a difference of wrappers. The server side > actually > > > > sends > > > > >> > the > > > > >> > > bytes lazily using FileChannel.transferTo. We need to make it > > > > >> possible to > > > > >> > > carry over that optimization. In some sense what we want to be > > > able > > > > >> to do > > > > >> > > is set a value to a Send instead of a ByteBuffer. > > > > >> > > > > > > >> > > Let me try to add that support to the protocol definition > stuff, > > > > will > > > > >> > > probably take me a few days to free up time. > > > > >> > > > > > > >> > > -Jay > > > > >> > > > > > > >> > > On Sun, Mar 22, 2015 at 7:44 PM, Gwen Shapira < > > > > gshap...@cloudera.com> > > > > >> > > wrote: > > > > >> > > > > > > >> > > > In case anyone is still following this thread, I need a bit > of > > > > help > > > > >> :) > > > > >> > > > > > > > >> > > > The old FetchResponse.PartitionData included a MessageSet > > > object. > > > > >> > > > The new FetchResponse.PartitionData includes a ByteBuffer. > > > > >> > > > > > > > >> > > > However, when we read from logs, we return a MessageSet, and > > as > > > > far > > > > >> as > > > > >> > I > > > > >> > > > can see, these can't be converted to ByteBuffers (at least > not > > > > >> without > > > > >> > > > copying their data). > > > > >> > > > > > > > >> > > > Did anyone consider how to reconcile the MessageSets with > the > > > new > > > > >> > > > FetchResponse objects? > > > > >> > > > > > > > >> > > > Gwen > > > > >> > > > > > > > >> > > > > > > > >> > > > On Sat, Mar 21, 2015 at 6:54 PM, Gwen Shapira < > > > > >> gshap...@cloudera.com> > > > > >> > > > wrote: > > > > >> > > > > > > > >> > > > > Note: I'm also treating ZkUtils as if it was a public API > > > (i.e. > > > > >> > > > converting > > > > >> > > > > objects that are returned into o.a.k.common equivalents > but > > > not > > > > >> > > changing > > > > >> > > > > ZkUtils itself). > > > > >> > > > > I know its not public, but I suspect I'm not the only > > > developer > > > > >> here > > > > >> > > who > > > > >> > > > > has tons of external code that uses it. > > > > >> > > > > > > > > >> > > > > Gwen > > > > >> > > > > > > > > >> > > > > On Wed, Mar 18, 2015 at 5:48 PM, Gwen Shapira < > > > > >> gshap...@cloudera.com > > > > >> > > > > > > >> > > > > wrote: > > > > >> > > > > > > > > >> > > > >> We can't rip them out completely, unfortunately - the > > > > >> SimpleConsumer > > > > >> > > > uses > > > > >> > > > >> them. > > > > >> > > > >> > > > > >> > > > >> So we'll need conversion at some point. I'll try to make > > the > > > > >> > > > >> conversion point "just before hitting a public API that > we > > > > can't > > > > >> > > > >> modify", and hopefully it won't look too arbitrary. > > > > >> > > > >> > > > > >> > > > >> > > > > >> > > > >> > > > > >> > > > >> On Wed, Mar 18, 2015 at 5:24 PM, Jay Kreps < > > > > jay.kr...@gmail.com> > > > > >> > > wrote: > > > > >> > > > >> > I think either approach is okay in the short term. > > However > > > > our > > > > >> > goal > > > > >> > > > >> should > > > > >> > > > >> > be to eventually get rid of that duplicate code, so if > > you > > > > are > > > > >> up > > > > >> > > for > > > > >> > > > >> just > > > > >> > > > >> > ripping and cutting that may get us there sooner. > > > > >> > > > >> > > > > > >> > > > >> > -Jay > > > > >> > > > >> > > > > > >> > > > >> > On Wed, Mar 18, 2015 at 5:19 PM, Gwen Shapira < > > > > >> > > gshap...@cloudera.com> > > > > >> > > > >> wrote: > > > > >> > > > >> > > > > > >> > > > >> >> Thanks! > > > > >> > > > >> >> > > > > >> > > > >> >> Another clarification: > > > > >> > > > >> >> The Common request/responses use slightly different > > > > >> > infrastructure > > > > >> > > > >> >> objects: Node instead of Broker, TopicPartition > instead > > of > > > > >> > > > >> >> TopicAndPartition and few more. > > > > >> > > > >> >> > > > > >> > > > >> >> I can write utilities to convert Node to Broker to > > > minimize > > > > >> the > > > > >> > > scope > > > > >> > > > >> >> of the change. > > > > >> > > > >> >> Or I can start replacing Brokers with Nodes across the > > > > board. > > > > >> > > > >> >> > > > > >> > > > >> >> I'm currently taking the second approach - i.e, if > > > > >> > MetadataRequest > > > > >> > > is > > > > >> > > > >> >> now returning Node, I'm changing the entire line of > > > > >> dependencies > > > > >> > to > > > > >> > > > >> >> use Nodes instead of broker. > > > > >> > > > >> >> > > > > >> > > > >> >> Is this acceptable, or do we want to take a more > minimal > > > > >> approach > > > > >> > > for > > > > >> > > > >> >> this patch and do a larger replacement as a follow up? > > > > >> > > > >> >> > > > > >> > > > >> >> Gwen > > > > >> > > > >> >> > > > > >> > > > >> >> > > > > >> > > > >> >> > > > > >> > > > >> >> > > > > >> > > > >> >> On Wed, Mar 18, 2015 at 3:32 PM, Jay Kreps < > > > > >> jay.kr...@gmail.com> > > > > >> > > > >> wrote: > > > > >> > > > >> >> > Great. > > > > >> > > > >> >> > > > > > >> > > > >> >> > For (3) yeah I think we should just think through > the > > > > >> > end-to-end > > > > >> > > > >> pattern > > > > >> > > > >> >> > for these versioned requests since it seems like we > > will > > > > >> have a > > > > >> > > > >> number of > > > > >> > > > >> >> > them. The serialization code used as you described > > gets > > > us > > > > >> to > > > > >> > the > > > > >> > > > >> right > > > > >> > > > >> >> > Struct which the user would then wrap in something > > like > > > > >> > > > >> ProduceRequest. > > > > >> > > > >> >> > Presumably there would just be one ProduceRequest > that > > > > would > > > > >> > > > >> internally > > > > >> > > > >> >> > fill in things like null or otherwise adapt the > struct > > > to > > > > a > > > > >> > > usable > > > > >> > > > >> >> object. > > > > >> > > > >> >> > On the response side we would have the version from > > the > > > > >> request > > > > >> > > to > > > > >> > > > >> use > > > > >> > > > >> >> for > > > > >> > > > >> >> > correct versioning. On question is whether this is > > > enough > > > > or > > > > >> > > > whether > > > > >> > > > >> we > > > > >> > > > >> >> > need to have switches in KafkaApis to do things like > > > > >> > > > >> >> > if(produceRequest.version == 3) > > > > >> > > > >> >> > // do something > > > > >> > > > >> >> > else > > > > >> > > > >> >> > // do something else > > > > >> > > > >> >> > > > > > >> > > > >> >> > Basically it would be good to be able to write a > quick > > > > wiki > > > > >> > that > > > > >> > > > was > > > > >> > > > >> like > > > > >> > > > >> >> > "how to add or modify a kafka api" that explained > the > > > > right > > > > >> way > > > > >> > > to > > > > >> > > > >> do all > > > > >> > > > >> >> > this. > > > > >> > > > >> >> > > > > > >> > > > >> >> > I don't think any of this necessarily blocks this > > ticket > > > > >> since > > > > >> > at > > > > >> > > > the > > > > >> > > > >> >> > moment we don't have tons of versions of requests > out > > > > there. > > > > >> > > > >> >> > > > > > >> > > > >> >> > -Jay > > > > >> > > > >> >> > > > > > >> > > > >> >> > On Wed, Mar 18, 2015 at 2:50 PM, Gwen Shapira < > > > > >> > > > gshap...@cloudera.com > > > > >> > > > >> > > > > > >> > > > >> >> wrote: > > > > >> > > > >> >> > > > > > >> > > > >> >> >> See inline responses: > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> On Wed, Mar 18, 2015 at 2:26 PM, Jay Kreps < > > > > >> > jay.kr...@gmail.com > > > > >> > > > > > > > >> > > > >> wrote: > > > > >> > > > >> >> >> > Hey Gwen, > > > > >> > > > >> >> >> > > > > > >> > > > >> >> >> > This makes sense to me. > > > > >> > > > >> >> >> > > > > > >> > > > >> >> >> > A couple of thoughts, mostly confirming what you > > > said I > > > > >> > think: > > > > >> > > > >> >> >> > > > > > >> > > > >> >> >> > 1. Ideally we would move completely over to > the > > > new > > > > >> style > > > > >> > > of > > > > >> > > > >> >> request > > > > >> > > > >> >> >> > definition for server-side processing, even > for > > > the > > > > >> > > internal > > > > >> > > > >> >> >> requests. This > > > > >> > > > >> >> >> > way all requests would have the same > header/body > > > > >> struct > > > > >> > > > stuff. > > > > >> > > > >> As > > > > >> > > > >> >> you > > > > >> > > > >> >> >> say > > > > >> > > > >> >> >> > for the internal requests we can just delete > the > > > > scala > > > > >> > > code. > > > > >> > > > >> For > > > > >> > > > >> >> the > > > > >> > > > >> >> >> old > > > > >> > > > >> >> >> > clients they will continue to use their old > > > request > > > > >> > > > definitions > > > > >> > > > >> >> until > > > > >> > > > >> >> >> we > > > > >> > > > >> >> >> > eol them. I would propose that new changes > will > > go > > > > >> only > > > > >> > > into > > > > >> > > > >> the > > > > >> > > > >> >> new > > > > >> > > > >> >> >> > request/response objects and the old scala > ones > > > will > > > > >> be > > > > >> > > > >> permanently > > > > >> > > > >> >> >> stuck > > > > >> > > > >> >> >> > on their current version until discontinued. > So > > > > after > > > > >> > this > > > > >> > > > >> change > > > > >> > > > >> >> >> that old > > > > >> > > > >> >> >> > scala code could be considered frozen. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> SimpleConsumer is obviously stuck with the old > > > > >> > request/response. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> The Producers can be converted to the common > > > > >> request/response > > > > >> > > > >> without > > > > >> > > > >> >> >> breaking compatibility. > > > > >> > > > >> >> >> I think we should do this (even though it requires > > > > fiddling > > > > >> > with > > > > >> > > > >> >> >> additional network serialization code), just so we > > can > > > > >> throw > > > > >> > the > > > > >> > > > old > > > > >> > > > >> >> >> ProduceRequest away. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> Does that make sense? > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> > 2. I think it would be reasonable to keep all > > the > > > > >> > requests > > > > >> > > > >> under > > > > >> > > > >> >> >> common, > > > > >> > > > >> >> >> > even though as you point out there is > currently > > no > > > > use > > > > >> > for > > > > >> > > > >> some of > > > > >> > > > >> >> >> them > > > > >> > > > >> >> >> > beyond broker-to-broker communication at the > > > moment. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> Yep. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> > 3. We should think a little about how > versioning > > > > will > > > > >> > work. > > > > >> > > > >> Making > > > > >> > > > >> >> >> this > > > > >> > > > >> >> >> > convenient on the server side is an important > > goal > > > > for > > > > >> > the > > > > >> > > > new > > > > >> > > > >> >> style > > > > >> > > > >> >> >> of > > > > >> > > > >> >> >> > request definition. At the serialization level > > we > > > > now > > > > >> > > handle > > > > >> > > > >> >> >> versioning but > > > > >> > > > >> >> >> > the question we should discuss and work out is > > how > > > > >> this > > > > >> > > will > > > > >> > > > >> map to > > > > >> > > > >> >> >> the > > > > >> > > > >> >> >> > request objects (which I assume will remain > > > > >> unversioned). > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> The way I see it working (I just started on this, > so > > I > > > > may > > > > >> > have > > > > >> > > > >> gaps): > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> * Request header contains the version > > > > >> > > > >> >> >> * When we read the request, we use > > > > ProtoUtils.requestSchema > > > > >> > > which > > > > >> > > > >> >> >> takes version as a parameter and is responsible to > > give > > > > us > > > > >> the > > > > >> > > > right > > > > >> > > > >> >> >> Schema, which we use to read the buffer and get the > > > > correct > > > > >> > > > struct. > > > > >> > > > >> >> >> * KafkaApis handlers have the header, so they can > use > > > it > > > > to > > > > >> > > access > > > > >> > > > >> the > > > > >> > > > >> >> >> correct fields, build the correct response, etc. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> Does that sound about right? > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> > 4. Ideally after this refactoring the network > > > > package > > > > >> > > should > > > > >> > > > >> not be > > > > >> > > > >> >> >> > dependent on the individual request objects. > The > > > > >> > intention > > > > >> > > is > > > > >> > > > >> that > > > > >> > > > >> >> >> stuff in > > > > >> > > > >> >> >> > kafka.network is meant to be generic network > > > > >> > infrastructure > > > > >> > > > >> that > > > > >> > > > >> >> >> doesn't > > > > >> > > > >> >> >> > know about the particular fetch/produce apis > we > > > have > > > > >> > > > >> implemented on > > > > >> > > > >> >> >> top. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> I'll make a note to validate that this is the case. > > > > >> > > > >> >> >> > > > > >> > > > >> >> >> > > > > > >> > > > >> >> >> > -Jay > > > > >> > > > >> >> >> > > > > > >> > > > >> >> >> > On Wed, Mar 18, 2015 at 11:11 AM, Gwen Shapira < > > > > >> > > > >> gshap...@cloudera.com > > > > >> > > > >> >> > > > > > >> > > > >> >> >> > wrote: > > > > >> > > > >> >> >> > > > > > >> > > > >> >> >> >> Hi Jun, > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> I was taking a slightly different approach. Let > me > > > > know > > > > >> if > > > > >> > it > > > > >> > > > >> makes > > > > >> > > > >> >> >> >> sense to you: > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> 1. Get the bytes from network (kinda > > unavoidable...) > > > > >> > > > >> >> >> >> 2. Modify RequestChannel.Request to contain > header > > > and > > > > >> body > > > > >> > > > >> (instead > > > > >> > > > >> >> >> >> of a single object) > > > > >> > > > >> >> >> >> 3. Create the head and body from bytes as > follow: > > > > >> > > > >> >> >> >> val header: RequestHeader = > > > > >> RequestHeader.parse(buffer) > > > > >> > > > >> >> >> >> val apiKey: Int = header.apiKey > > > > >> > > > >> >> >> >> val body: Struct = > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> > > > > >> > > > >> >> > > > > >> > > > >> > > > > >> > > > > > > > >> > > > > > >> > > > > > > ProtoUtils.currentRequestSchema(apiKey).read(buffer).asInstanceOf[Struct] > > > > >> > > > >> >> >> >> 4. KafkaAPIs will continue getting > > > > >> RequestChannel.Request, > > > > >> > > but > > > > >> > > > >> will > > > > >> > > > >> >> >> >> now have access to body and header separately. > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> I agree that I need a Request/Response objects > > that > > > > >> contain > > > > >> > > > only > > > > >> > > > >> the > > > > >> > > > >> >> >> >> body for all requests objects. > > > > >> > > > >> >> >> >> I'm thinking of implementing them in > > > > >> o.a.k.Common.Requests > > > > >> > in > > > > >> > > > >> Java > > > > >> > > > >> >> for > > > > >> > > > >> >> >> >> consistency. > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> When we are discussing the requests/responses > used > > > in > > > > >> > > > >> SimpleConsumer, > > > > >> > > > >> >> >> >> we mean everything used in javaapi, right? > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> Gwen > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> >> On Wed, Mar 18, 2015 at 9:55 AM, Jun Rao < > > > > >> j...@confluent.io > > > > >> > > > > > > >> > > > >> wrote: > > > > >> > > > >> >> >> >> > Hi, Gwen, > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > I was thinking that we will be doing the > > following > > > > in > > > > >> > > > >> KAFKA-1927. > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > 1. Get the bytes from network. > > > > >> > > > >> >> >> >> > 2. Use a new generic approach to convert bytes > > > into > > > > >> > request > > > > >> > > > >> >> objects. > > > > >> > > > >> >> >> >> > 2.1 Read the fixed request header (using the > > util > > > in > > > > >> > > client). > > > > >> > > > >> >> >> >> > 2.2 Based on the request id in the header, > > > > deserialize > > > > >> > the > > > > >> > > > >> rest of > > > > >> > > > >> >> the > > > > >> > > > >> >> >> >> > bytes into a request specific object (using > the > > > new > > > > >> java > > > > >> > > > >> objects). > > > > >> > > > >> >> >> >> > 3. We will then be passing a header and an > > > > >> > > > >> AbstractRequestResponse > > > > >> > > > >> >> to > > > > >> > > > >> >> >> >> > KafkaApis. > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > In order to do that, we will need to create > > > similar > > > > >> > > > >> >> request/response > > > > >> > > > >> >> >> >> > objects for internal requests such as > > StopReplica, > > > > >> > > > >> LeaderAndIsr, > > > > >> > > > >> >> >> >> > UpdateMetadata, ControlledShutdown. Not sure > > > whether > > > > >> they > > > > >> > > > >> should be > > > > >> > > > >> >> >> >> written > > > > >> > > > >> >> >> >> > in java or scala, but perhaps they should be > > only > > > in > > > > >> the > > > > >> > > core > > > > >> > > > >> >> project. > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > Also note, there are some scala > > requests/responses > > > > >> used > > > > >> > > > >> directly in > > > > >> > > > >> >> >> >> > SimpleConsumer. Since that's our public api, > we > > > > can't > > > > >> > > remove > > > > >> > > > >> those > > > > >> > > > >> >> >> scala > > > > >> > > > >> >> >> >> > objects until the old consumer is phased out. > We > > > can > > > > >> > remove > > > > >> > > > the > > > > >> > > > >> >> rest > > > > >> > > > >> >> >> of > > > > >> > > > >> >> >> >> the > > > > >> > > > >> >> >> >> > scala request objects. > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > Thanks, > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > Jun > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> > On Tue, Mar 17, 2015 at 6:08 PM, Gwen Shapira > < > > > > >> > > > >> >> gshap...@cloudera.com> > > > > >> > > > >> >> >> >> wrote: > > > > >> > > > >> >> >> >> > > > > > >> > > > >> >> >> >> >> Hi, > > > > >> > > > >> >> >> >> >> > > > > >> > > > >> >> >> >> >> I'm starting this thread for the various > > > questions > > > > I > > > > >> run > > > > >> > > > into > > > > >> > > > >> >> while > > > > >> > > > >> >> >> >> >> refactoring the server to use client requests > > and > > > > >> > > responses. > > > > >> > > > >> >> >> >> >> > > > > >> > > > >> >> >> >> >> Help is appreciated :) > > > > >> > > > >> >> >> >> >> > > > > >> > > > >> >> >> >> >> First question: LEADER_AND_ISR request and > > > > >> STOP_REPLICA > > > > >> > > > >> request > > > > >> > > > >> >> are > > > > >> > > > >> >> >> >> >> unimplemented in the client. > > > > >> > > > >> >> >> >> >> > > > > >> > > > >> >> >> >> >> Do we want to implement them as part of this > > > > >> > refactoring? > > > > >> > > > >> >> >> >> >> Or should we continue using the scala > > > > implementation > > > > >> for > > > > >> > > > >> those? > > > > >> > > > >> >> >> >> >> > > > > >> > > > >> >> >> >> >> Gwen > > > > >> > > > >> >> >> >> >> > > > > >> > > > >> >> >> >> > > > > >> > > > >> >> >> > > > > >> > > > >> >> > > > > >> > > > >> > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > > > > > > > > > > > > > > > > >
