ok, opened KAFKA-1841 . KAFKA-1634 also related. -Dana
On Mon, Jan 5, 2015 at 10:55 AM, Gwen Shapira <gshap...@cloudera.com> wrote: > Ooh, I see what you mean - the OffsetAndMetadata (or PartitionData) > part of the Map changed, which will modify the wire protocol. > > This is actually not handled in the Java client either. It will send > the timestamp no matter which version is used. > > This looks like a bug and I'd even mark it as blocker for 0.8.2 since > it may prevent rolling upgrades. > > Are you opening the JIRA? > > Gwen > > On Mon, Jan 5, 2015 at 10:28 AM, Dana Powers <dana.pow...@rd.io> wrote: > > specifically comparing 0.8.1 -- > > > > > https://github.com/apache/kafka/blob/0.8.1/core/src/main/scala/kafka/api/OffsetCommitRequest.scala#L37-L50 > > ``` > > (1 to partitionCount).map(_ => { > > val partitionId = buffer.getInt > > val offset = buffer.getLong > > val metadata = readShortString(buffer) > > (TopicAndPartition(topic, partitionId), OffsetMetadataAndError(offset, > > metadata)) > > }) > > ``` > > > > totrunk -- > > > > > https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/api/OffsetCommitRequest.scala#L44-L69 > > ``` > > (1 to partitionCount).map(_ => { > > val partitionId = buffer.getInt > > val offset = buffer.getLong > > val timestamp = { > > val given = buffer.getLong > > if (given == -1L) now else given > > } > > val metadata = readShortString(buffer) > > (TopicAndPartition(topic, partitionId), OffsetAndMetadata(offset, > > metadata, timestamp)) > > }) > > ``` > > > > should the `timestamp` buffer read be wrapped in an api version check? > > > > > > Dana Powers > > Rdio, Inc. > > dana.pow...@rd.io > > rdio.com/people/dpkp/ > > > > On Mon, Jan 5, 2015 at 9:49 AM, Gwen Shapira <gshap...@cloudera.com> > wrote: > > > >> Ah, I see :) > >> > >> The readFrom function basically tries to read two extra fields if you > >> are on version 1: > >> > >> if (versionId == 1) { > >> groupGenerationId = buffer.getInt > >> consumerId = readShortString(buffer) > >> } > >> > >> The rest looks identical in version 0 and 1, and still no timestamp in > >> sight... > >> > >> Gwen > >> > >> On Mon, Jan 5, 2015 at 9:33 AM, Dana Powers <dana.pow...@rd.io> wrote: > >> > Hi Gwen, I am using/writing kafka-python to construct api requests and > >> have > >> > not dug too deeply into the server source code. But I believe it is > >> > kafka/api/OffsetCommitRequest.scala and specifically the readFrom > method > >> > used to decode the wire protocol. > >> > > >> > -Dana > >> > OffsetCommitRequest has two constructors now: > >> > > >> > For version 0: > >> > OffsetCommitRequest(String groupId, Map<TopicPartition, > >> > PartitionData> offsetData) > >> > > >> > And version 1: > >> > OffsetCommitRequest(String groupId, int generationId, String > >> > consumerId, Map<TopicPartition, PartitionData> offsetData) > >> > > >> > None of them seem to require timestamps... so I'm not sure where you > >> > see that this is required. Can you share an example? > >> > > >> > Gwen > >> > > >> > On Sun, Jan 4, 2015 at 11:15 PM, Dana Powers <dana.pow...@rd.io> > wrote: > >> >> Hi Joel, > >> >> > >> >> I'm looking more closely at the OffsetCommitRequest wire protocol > change > >> >> you mentioned below, and I cannot figure out how to explicitly > >> construct a > >> >> request with the earlier version. Should the api version be > different > >> for > >> >> requests that do not include it and/or servers that do not support > the > >> >> timestamp field? It looks like 0.8.1.1 did not include the timestamp > >> > field > >> >> and used api version 0. But 0.8.2-beta seems to now require > timestamps > >> >> even when I explicitly encode OffsetCommitRequest api version 0 > (server > >> >> logs a BufferUnderflowException). > >> >> > >> >> Is this the expected server behavior? Can you provide any tips on > how > >> >> third-party clients should manage the wire-protocol change for this > api > >> >> method (I'm working on kafka-python)? > >> >> > >> >> Thanks, > >> >> > >> >> -Dana > >> >> > >> >> On Tue, Nov 18, 2014 at 1:27 PM, Joel Koshy <jjkosh...@gmail.com> > >> wrote: > >> >> > >> >>> Yes it should be backwards compatible. So for e.g., you should be > able > >> >>> to use an 0.8.1 client with an 0.8.2 broker. In general, you should > >> >>> not upgrade your clients until after the brokers have been upgraded. > >> >>> However, you can point an 0.8.2 client at an 0.8.1 broker. One wire > >> >>> protocol change I'm aware of is the OffsetCommitRequest. There is a > >> >>> change in the OffsetCommitRequest format (KAFKA-1634) although you > can > >> >>> explicitly construct an OffsetCommitRequest with the earlier > version. > >> >>> > >> >>> Thanks, > >> >>> > >> >>> Joel > >> >>> > >> >>> On Tue, Nov 18, 2014 at 03:39:41PM -0500, Marius Bogoevici wrote: > >> >>> > Hi Joel, > >> >>> > > >> >>> > Thanks for all the clarifications! Just another question on this: > >> will > >> >>> > 0.8.2 be backwards compatible with 0.8.1, just as 0.8.1 was with > 0.8? > >> >>> > Generally speaking, would there be any concerns with using the > 0.8.2 > >> >>> > consumer with a 0.8.1 broker, for instance? > >> >>> > > >> >>> > Marius > >> >>> > > >> >>> > On Tue, Nov 18, 2014 at 2:55 PM, Joel Koshy <jjkosh...@gmail.com> > >> > wrote: > >> >>> > > >> >>> > > Inline.. > >> >>> > > > >> >>> > > On Tue, Nov 18, 2014 at 04:26:04AM -0500, Marius Bogoevici > wrote: > >> >>> > > > Hello everyone, > >> >>> > > > > >> >>> > > > I have a few questions about the current status and future of > the > >> >>> Kafka > >> >>> > > > consumers. > >> >>> > > > > >> >>> > > > We have been working to adding Kafka support in Spring XD [1], > >> >>> currently > >> >>> > > > using the high level consumer via Spring Integration Kafka > [2]. > >> We > >> >>> are > >> >>> > > > working on adding features such as: > >> >>> > > > - the ability to control offsets/replay topics; > >> >>> > > > - the ability to control partition allocation across multiple > >> >>> consumers; > >> >>> > > > > >> >>> > > > We are currently at version 0.8.1.1, so using the simple > consumer > >> > is > >> >>> a > >> >>> > > > pretty straightforward choice right now. However, in the > light of > >> > the > >> >>> > > > upcoming consumer changes for 0.8.2 and 0.9, I have a few > >> > questions: > >> >>> > > > > >> >>> > > > 1) With respect to the consumer redesign for 0.9, what is the > >> > future > >> >>> of > >> >>> > > the > >> >>> > > > Simple Consumer and High Level Consumer? To my best > >> understanding, > >> >>> the > >> >>> > > > existing high level consumer API will be deprecated in favour > of > >> > the > >> >>> new > >> >>> > > > consumer API. What is the future of the Simple Consumer, in > this > >> >>> case? it > >> >>> > > > will continue to exist as a low-level API implementing the > Kafka > >> >>> protocol > >> >>> > > > [3] and providing the building blocks for the new consumer, or > >> will > >> >>> it be > >> >>> > > > deprecated as well? > >> >>> > > > >> >>> > > The new consumer will subsume both use-cases (simple and > >> high-level). > >> >>> > > You can still use the old SimpleConsumer if you wish - i.e., the > >> wire > >> >>> > > protocol for fetch and other requests will still be supported. > >> >>> > > > >> >>> > > > > >> >>> > > > 2) Regarding the new consumer: the v0.8.2 codebase contains an > >> > early > >> >>> > > > implementation of it, but since this a feature scheduled only > for > >> >>> 0.9, > >> >>> > > what > >> >>> > > > is its status as well? Is it included only as a future > reference > >> > and > >> >>> for > >> >>> > > > stabilizing the API? > >> >>> > > > >> >>> > > It is a WIP so you cannot really use it. > >> >>> > > > >> >>> > > > 3) Obviously, offset management is a concern if using the > simple > >> >>> > > consumer, > >> >>> > > > so - wondering about the Offset Management API as well. The > Kafka > >> >>> > > protocol > >> >>> > > > document specifically indicates that it will be fully > functional > >> in > >> >>> 0.8.2 > >> >>> > > > [4] - however, a functional implementation is already > available > >> in > >> >>> > > 0.8.1.1 > >> >>> > > > (accessible via the SimpleConsumer API but not documented in > >> [5]). > >> >>> Again, > >> >>> > > > trying to understand the extent of what 0.8.1.1 already > supports > >> >>> > > > (ostensibly, the offset manager support seems to have been > added > >> >>> only in > >> >>> > > > 0.8.2 - please correct me if I am wrong), and whether if it is > >> >>> > > recommended > >> >>> > > > for use in production in any form (with the caveats that > >> accompany > >> >>> the > >> >>> > > use > >> >>> > > > of ZooKeeper). > >> >>> > > > >> >>> > > In 0.8.2 the OffsetCommitRequest and OffsetFetchRequest will use > >> > Kafka > >> >>> > > as the offsets storage mechanism (not zookeeper). High-level > Java > >> >>> > > consumers can choose to store offsets in ZooKeeper instead by > >> setting > >> >>> > > offsets.storage=zookeeper > >> >>> > > > >> >>> > > However, if you are using the simple consumer and wish to store > >> >>> > > offsets in ZooKeeper you will need to commit to ZooKeeper > directly. > >> >>> > > You can use ZkUtils in the kafka.utils package for this. > >> >>> > > > >> >>> > > If you wish to move to Kafka-based offsets we will be adding a > new > >> >>> > > OffsetsClient that can be used to commit/fetch offsets to/from > >> Kafka. > >> >>> > > This is currently not listed as a blocker for 0.8.2 but I think > we > >> >>> > > should include it. I will update that ticket. > >> >>> > > > >> >>> > > > 4) Trying to interpret the existing examples in [6] and the > >> > comments > >> >>> on > >> >>> > > [7] > >> >>> > > > - the version of the Offset Management API that exists in > 0.8.1.1 > >> > is > >> >>> > > using > >> >>> > > > ZooKeeper - whereas ZooKeeper will be optional in 0.8.2 - to > be > >> >>> replaced > >> >>> > > by > >> >>> > > > Kafka, and phased out if possible. To my understanding, the > >> switch > >> >>> > > between > >> >>> > > > the two will be controlled by the broker configuration (along > >> with > >> >>> other > >> >>> > > > parameters that control the performance of offset queues. Is > that > >> >>> > > correct? > >> >>> > > > >> >>> > > The switch is a client-side configuration. That wiki is not > >> >>> > > up-to-date. The most current documentation is available as a > patch > >> in > >> >>> > > https://issues.apache.org/jira/browse/KAFKA-1729 > >> >>> > > > >> >>> > > > 5) Also, wondering about the timeline of 0.8.2 - according to > the > >> >>> > > roadmaps > >> >>> > > > it should be released relatively shortly. Is that correct? > >> >>> > > > >> >>> > > Yes - once the blockers are ironed out. > >> >>> > > > >> >>> > > > > >> >>> > > > Thanks, > >> >>> > > > Marius > >> >>> > > > > >> >>> > > > [1] http://projects.spring.io/spring-xd/ > >> >>> > > > [2] > https://github.com/spring-projects/spring-integration-kafka > >> >>> > > > [3] > >> >>> > > > > >> >>> > > > >> >>> > >> > > >> > https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol > >> >>> > > > [4] > >> >>> > > > > >> >>> > > > >> >>> > >> > > >> > https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol#AGuideToTheKafkaProtocol-OffsetCommit/FetchAPI > >> >>> > > > [5] > >> > http://kafka.apache.org/082/documentation.html#simpleconsumerapi > >> >>> > > > [6] > >> >>> > > > > >> >>> > > > >> >>> > >> > > >> > https://cwiki.apache.org/confluence/display/KAFKA/Committing+and+fetching+consumer+offsets+in+Kafka > >> >>> > > > [7] https://issues.apache.org/jira/browse/KAFKA-1729 > >> >>> > > > >> >>> > > > >> >>> > >> >>> > >> >
