No errors. But if I enable caching I see performance drop considerably. The 
workaround was to disable caching. The same thing is still true in 10.2.1.

Ara.

> On May 2, 2017, at 12:55 PM, Eno Thereska <eno.there...@gmail.com> wrote:
>
> Hi Ara,
>
> The PR https://github.com/apache/kafka/pull/2645 has gone to both trunk and
> 0.10.2.1, I just checked. What error are you seeing, could you give us an
> update?
>
> Thanks
> Eno
>
> On Fri, Apr 28, 2017 at 7:10 PM, Ara Ebrahimi <ara.ebrah...@argyledata.com>
> wrote:
>
>> Hi,
>>
>> I upgraded to 0.10.2.1 yesterday, enabled caching for session windows and
>> tested again. It doesn’t seem to be fixed?
>>
>> Ara.
>>
>>> On Mar 27, 2017, at 2:10 PM, Damian Guy <damian....@gmail.com> wrote:
>>>
>>> Hi Ara,
>>>
>>> There is a performance issue in the 0.10.2 release of session windows. It
>>> is fixed with this PR: https://github.com/apache/kafka/pull/2645
>>> You can work around this on 0.10.2 by calling the aggregate(..),
>> reduce(..)
>>> etc methods and supplying StateStoreSupplier<SessionStore> with caching
>>> disabled, i.e, by doing something like:
>>>
>>> final StateStoreSupplier<SessionStore> sessionStore =
>>> Stores.create(*"session-store-name"*)
>>>   .withKeys(Serdes.String())
>>>   .withValues(Serdes.String())
>>>   .persistent()
>>>   .sessionWindowed(TimeUnit.MINUTES.toMillis(7))
>>>   .build();
>>>
>>>
>>> The fix has also been cherry-picked to the 0.10.2 branch, so you could
>>> build from source and not have to create the StateStoreSupplier.
>>>
>>> Thanks,
>>> Damian
>>>
>>> On Mon, 27 Mar 2017 at 21:56 Ara Ebrahimi <ara.ebrah...@argyledata.com>
>>> wrote:
>>>
>>> Thanks for the response Mathias!
>>>
>>> The reason we want this exact task assignment to happen is that a
>> critical
>>> part of our pipeline involves grouping relevant records together (that’s
>>> what the aggregate function in the topology is for). And for hot keys
>> this
>>> can lead to sometimes 100s of records to get grouped together. Even
>> worse,
>>> these records are session bound, we use session windows. Hence we see
>> lots
>>> of activity around the store backing the aggregate function and even
>> though
>>> we use SSD drives we’re not seeing the kind of performance we want to
>> see.
>>> It seems like the aggregate function leads to lots of updates to these
>> hot
>>> keys which lead to lots of rocksdb activity.
>>>
>>> Now there are many ways to fix this problem:
>>> - just don’t aggregate, create an algorithm which is not reliant on
>>> grouping/aggregating records. Not what we can do with our tight schedule
>>> right now.
>>> - do grouping/aggregating but employ n instances and rely on uniform
>>> distribution of these tasks. This is the easiest solution and what we
>>> expected to work but didn’t work as you can tell from this thread. We
>> threw
>>> 4 instances at it but only 2 got used.
>>> - tune rocksdb? I tried this actually but it didn’t really help us much,
>>> aside from the fact that tuning rocksdb is very tricky.
>>> - use in-memory store instead? Unfortunately we have to use session
>> windows
>>> for this aggregate function and apparently there’s no in-memory session
>>> store impl? I tried to create one but soon realized it’s too much work
>> :) I
>>> looked at default PartitionAssigner code too, but that ain’t trivial
>> either.
>>>
>>> So I’m a bit hopeless :(
>>>
>>> Ara.
>>>
>>> On Mar 27, 2017, at 1:35 PM, Matthias J. Sax <matth...@confluent.io
>> <mailto:
>>> matth...@confluent.io>> wrote:
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>> From: "Matthias J. Sax" <matth...@confluent.io<mailto:
>> matth...@confluent.io
>>>>>
>>> Subject: Re: more uniform task assignment across kafka stream nodes
>>> Date: March 27, 2017 at 1:35:30 PM PDT
>>> To: users@kafka.apache.org<mailto:users@kafka.apache.org>
>>> Reply-To: <users@kafka.apache.org<mailto:users@kafka.apache.org>>
>>>
>>>
>>> Ara,
>>>
>>> thanks for the detailed information.
>>>
>>> If I parse this correctly, both instances run the same number of tasks
>>> (12 each). That is all Streams promises.
>>>
>>> To come back to your initial question:
>>>
>>> Is there a way to tell kafka streams to uniformly assign partitions
>> across
>>> instances? If I have n kafka streams instances running, I want each to
>>> handle EXACTLY 1/nth number of partitions. No dynamic task assignment
>>> logic. Just dumb 1/n assignment.
>>>
>>> That is exactly what you get: each of you two instances get 24/2 = 12
>>> tasks assigned. That is dump 1/n assignment, isn't it? So my original
>>> response was correct.
>>>
>>> However, I now understand better what you are actually meaning by your
>>> question. Note that Streams does not distinguish "type" of tasks -- it
>>> only sees 24 tasks and assigns those in a balanced way.
>>>
>>> Thus, currently there is no easy way to get the assignment you want to
>>> have, except, you implement you own `PartitionAssignor`.
>>>
>>> This is the current implementation for 0.10.2
>>> https://github.com/apache/kafka/blob/0.10.2/streams/src/
>> main/java/org/apache/kafka/streams/processor/internals/
>> StreamPartitionAssignor.java
>>>
>>> You can, if you wish write your own assignor and set it via
>>> StreamsConfig. However, be aware that this might be tricky to get right
>>> and also might have runtime implications with regard to rebalancing and
>>> state store recovery. We recently improve the current implementation to
>>> avoid costly task movements:
>>> https://issues.apache.org/jira/browse/KAFKA-4677
>>>
>>> Thus, I would not recommend to implement an own `PartitionAssignor`.
>>>
>>>
>>> However, the root question is, why do you need this exact assignment you
>>> are looking for in the first place? Why is it "bad" if "types" of tasks
>>> are not distinguished? I would like to understand your requirement
>>> better -- it might be worth to improve Streams here.
>>>
>>>
>>> -Matthias
>>>
>>>
>>> On 3/27/17 12:57 PM, Ara Ebrahimi wrote:
>>> Hi,
>>>
>>> So, I simplified the topology by making sure we have only 1 source topic.
>>> Now I have 1 source topic, 8 partitions, 2 instances. And here’s how the
>>> topology looks like:
>>>
>>> instance 1:
>>>
>>> KafkaStreams processID: 48b58bc0-f600-4ec8-bc92-8cb3ea081aac
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-1
>>> Active tasks:
>>> StreamsTask taskId: 0_3
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-3]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-2
>>> Active tasks:
>>> StreamsTask taskId: 1_2
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-2]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-3
>>> Active tasks:
>>> StreamsTask taskId: 1_1
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-1]
>>> StreamsTask taskId: 2_7
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-7]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-4
>>> Active tasks:
>>> StreamsTask taskId: 2_0
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-0]
>>> StreamsTask taskId: 2_6
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-6]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-5
>>> Active tasks:
>>> StreamsTask taskId: 0_0
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-0]
>>> StreamsTask taskId: 1_6
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-6]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-6
>>> Active tasks:
>>> StreamsTask taskId: 1_0
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-0]
>>> StreamsTask taskId: 0_7
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-7]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-7
>>> Active tasks:
>>> StreamsTask taskId: 2_4
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-4]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-8
>>> Active tasks:
>>> StreamsTask taskId: 1_3
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-3]
>>> Standby tasks:
>>>
>>>
>>> instance 2:
>>>
>>> KafkaStreams processID: 092072f8-87be-4989-a94f-0ed544f5ca44
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-1
>>> Active tasks:
>>> StreamsTask taskId: 2_1
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-1]
>>> StreamsTask taskId: 2_5
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-5]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-2
>>> Active tasks:
>>> StreamsTask taskId: 0_4
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-4]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-3
>>> Active tasks:
>>> StreamsTask taskId: 2_2
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-2]
>>> StreamsTask taskId: 1_7
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-7]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-4
>>> Active tasks:
>>> StreamsTask taskId: 2_3
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000019:
>>> topics: [ml-features-avro-or]
>>> Partitions [ml-features-avro-or-3]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-5
>>> Active tasks:
>>> StreamsTask taskId: 0_1
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-1]
>>> StreamsTask taskId: 1_5
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-5]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-6
>>> Active tasks:
>>> StreamsTask taskId: 1_4
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000012:
>>> topics: [activities-by-phone-store-or-repartition]
>>> children: [KSTREAM-AGGREGATE-0000000009]
>>> KSTREAM-AGGREGATE-0000000009:
>>> states: [activities-by-phone-store-or]
>>> children: [KTABLE-TOSTREAM-0000000013]
>>> KTABLE-TOSTREAM-0000000013:
>>> children: [KSTREAM-FILTER-0000000014]
>>> KSTREAM-FILTER-0000000014:
>>> children: [KSTREAM-FILTER-0000000015]
>>> KSTREAM-FILTER-0000000015:
>>> children: [KSTREAM-MAP-0000000016]
>>> KSTREAM-MAP-0000000016:
>>> children: [KSTREAM-MAP-0000000017]
>>> KSTREAM-MAP-0000000017:
>>> children: [KSTREAM-SINK-0000000018]
>>> KSTREAM-SINK-0000000018:
>>> topic: ml-features-avro-or
>>> Partitions [activities-by-phone-store-or-repartition-4]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-7
>>> Active tasks:
>>> StreamsTask taskId: 0_2
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-2]
>>> StreamsTask taskId: 0_6
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-6]
>>> Standby tasks:
>>>
>>> StreamsThread appId: mar-23-modular
>>> StreamsThread clientId: mar-23-modular
>>> StreamsThread threadId: StreamThread-8
>>> Active tasks:
>>> StreamsTask taskId: 0_5
>>> ProcessorTopology:
>>> KSTREAM-SOURCE-0000000000:
>>> topics: [activities-avro-or]
>>> children: [KSTREAM-FILTER-0000000001]
>>> KSTREAM-FILTER-0000000001:
>>> children: [KSTREAM-MAP-0000000002]
>>> KSTREAM-MAP-0000000002:
>>> children: [KSTREAM-BRANCH-0000000003]
>>> KSTREAM-BRANCH-0000000003:
>>> children: [KSTREAM-BRANCHCHILD-0000000004, KSTREAM-BRANCHCHILD-
>> 0000000005]
>>> KSTREAM-BRANCHCHILD-0000000004:
>>> children: [KSTREAM-MAPVALUES-0000000006]
>>> KSTREAM-MAPVALUES-0000000006:
>>> children: [KSTREAM-FLATMAPVALUES-0000000007]
>>> KSTREAM-FLATMAPVALUES-0000000007:
>>> children: [KSTREAM-MAP-0000000008]
>>> KSTREAM-MAP-0000000008:
>>> children: [KSTREAM-FILTER-0000000011]
>>> KSTREAM-FILTER-0000000011:
>>> children: [KSTREAM-SINK-0000000010]
>>> KSTREAM-SINK-0000000010:
>>> topic: activities-by-phone-store-or-repartition
>>> KSTREAM-BRANCHCHILD-0000000005:
>>> Partitions [activities-avro-or-5]
>>> Standby tasks:
>>>
>>>
>>> activities-avro-or is input topic. ml-features-avro-or is output topic.
>> In
>>> the middle we have an aggregate (activities-by-phone-store-or-
>> repartition).
>>>
>>> On instance 1 I see 3 tasks for activities-avro-or and on instance 2 I
>> see
>>> 5. Bad.
>>>
>>> On instance 1 see 4 tasks for ml-features-avro-or. And 4 on instance 2.
>>> Good.
>>>
>>> On instance 1 see 5 tasks for activities-by-phone-store-or-repartition.
>> And
>>> 3 on instance 2. Bad.
>>>
>>> As I said in terms of offsets for all these partitions I see uniform
>>> distribution, so we’re not dealing with a bad key scenario.
>>>
>>> Ara.
>>>
>>> On Mar 25, 2017, at 6:43 PM, Matthias J. Sax <matth...@confluent.io
>> <mailto:
>>> matth...@confluent.io>> wrote:
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>> From: "Matthias J. Sax" <matth...@confluent.io<mailto:
>> matth...@confluent.io
>>>>>
>>> Subject: Re: more uniform task assignment across kafka stream nodes
>>> Date: March 25, 2017 at 6:43:12 PM PDT
>>> To: users@kafka.apache.org<mailto:users@kafka.apache.org>
>>> Reply-To: <users@kafka.apache.org<mailto:users@kafka.apache.org>>
>>>
>>>
>>> Please share the rest of your topology code (without any UDFs / business
>>> logic). Otherwise, I cannot give further advice.
>>>
>>> -Matthias
>>>
>>>
>>> On 3/25/17 6:08 PM, Ara Ebrahimi wrote:
>>> Via:
>>>
>>> builder.stream("topic1");
>>> builder.stream("topic2");
>>> builder.stream("topic3”);
>>>
>>> These are different kinds of topics consuming different avro objects.
>>>
>>> Ara.
>>>
>>> On Mar 25, 2017, at 6:04 PM, Matthias J. Sax <matth...@confluent.io
>> <mailto:
>>> matth...@confluent.io><mailto:matth...@confluent.io>> wrote:
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>> From: "Matthias J. Sax" <matth...@confluent.io<mailto:
>> matth...@confluent.io
>>>> <mailto:matth...@confluent.io>>
>>> Subject: Re: more uniform task assignment across kafka stream nodes
>>> Date: March 25, 2017 at 6:04:30 PM PDT
>>> To: users@kafka.apache.org<mailto:users@kafka.apache.org><mailto:
>>> users@kafka.apache.org>
>>> Reply-To: <users@kafka.apache.org<mailto:users@kafka.apache.org><mailto:
>>> users@kafka.apache.org>>
>>>
>>>
>>> Ara,
>>>
>>> How do you consume your topics? Via
>>>
>>> builder.stream("topic1", "topic2", "topic3);
>>>
>>> or via
>>>
>>> builder.stream("topic1");
>>> builder.stream("topic2");
>>> builder.stream("topic3");
>>>
>>> Both and handled differently with regard to creating tasks (partition to
>>> task assignment also depends on you downstream code though).
>>>
>>> If this does not help, can you maybe share the structure of processing?
>>> To dig deeper, we would need to know the topology DAG.
>>>
>>>
>>> -Matthias
>>>
>>>
>>> On 3/25/17 5:56 PM, Ara Ebrahimi wrote:
>>> Mathias,
>>>
>>> This apparently happens because we have more than 1 source topic. We
>> have 3
>>> source topics in the same application. So it seems like the task
>> assignment
>>> algorithm creates topologies not for one specific topic at a time but the
>>> total partitions across all source topics consumed in an application
>>> instance. Because we have some code dependencies between these 3 source
>>> topics we can’t separate them into 3 applications at this time. Hence the
>>> reason I want to get the task assignment algorithm basically do a uniform
>>> and simple task assignment PER source topic.
>>>
>>> Ara.
>>>
>>> On Mar 25, 2017, at 5:21 PM, Matthias J. Sax <matth...@confluent.io
>> <mailto:
>>> matth...@confluent.io><mailto:matth...@confluent.io><mailto:
>>> matth...@confluent.io>> wrote:
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>> From: "Matthias J. Sax" <matth...@confluent.io<mailto:
>> matth...@confluent.io
>>>> <mailto:matth...@confluent.io><mailto:matth...@confluent.io>>
>>> Subject: Re: more uniform task assignment across kafka stream nodes
>>> Date: March 25, 2017 at 5:21:47 PM PDT
>>> To: users@kafka.apache.org<mailto:users@kafka.apache.org><mailto:
>>> users@kafka.apache.org><mailto:users@kafka.apache.org>
>>> Reply-To: <users@kafka.apache.org<mailto:users@kafka.apache.org><mailto:
>>> users@kafka.apache.org><mailto:users@kafka.apache.org>>
>>>
>>>
>>> Hi,
>>>
>>> I am wondering why this happens in the first place. Streams,
>>> load-balanced over all running instances, and each instance should be
>>> the same number of tasks (and thus partitions) assigned.
>>>
>>> What is the overall assignment? Do you have StandyBy tasks configured?
>>> What version do you use?
>>>
>>>
>>> -Matthias
>>>
>>>
>>> On 3/24/17 8:09 PM, Ara Ebrahimi wrote:
>>> Hi,
>>>
>>> Is there a way to tell kafka streams to uniformly assign partitions
>> across
>>> instances? If I have n kafka streams instances running, I want each to
>>> handle EXACTLY 1/nth number of partitions. No dynamic task assignment
>>> logic. Just dumb 1/n assignment.
>>>
>>> Here’s our scenario. Lets say we have an “source" topic with 8
>> partitions.
>>> We also have 2 kafka streams instances. Each instances get assigned to
>>> handle 4 “source" topic partitions. BUT then we do a few maps and an
>>> aggregate. So data gets shuffled around. The map function uniformly
>>> distributes these across all partitions (I can verify that by looking at
>>> the partition offsets). After the map what I notice by looking at the
>>> topology is that one kafka streams instance get assigned to handle say 2
>>> aggregate repartition topics and the other one gets assigned 6. Even
>> worse,
>>> on bigger clusters (say 4 instances) we see say 2 nodes gets assigned
>>> downstream aggregate repartition topics and 2 other nodes assigned
>> NOTHING
>>> to handle.
>>>
>>> Ara.
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>>> privileged, proprietary, or otherwise confidential information. If you
>> have
>>> received it in error, please notify the sender immediately and delete the
>>> original. Any other use of the e-mail by you is prohibited. Thank you in
>>> advance for your cooperation.
>>>
>>> ________________________________
>>>
>>>
>>>
>>> ________________________________
>>>
>>> This message is for the designated recipient only and may contain
>> privileged, proprietary, or otherwise confidential information. If you have
>> received it in error, please notify the sender immediately and delete the
>> original. Any other use of the e-mail by you is prohibited. Thank you in
>> advance for your cooperation.
>>>
>>> ________________________________
>>
>>
>>
>>
>> ________________________________
>>
>> This message is for the designated recipient only and may contain
>> privileged, proprietary, or otherwise confidential information. If you have
>> received it in error, please notify the sender immediately and delete the
>> original. Any other use of the e-mail by you is prohibited. Thank you in
>> advance for your cooperation.
>>
>> ________________________________
>>
>
>
>
> ________________________________
>
> This message is for the designated recipient only and may contain privileged, 
> proprietary, or otherwise confidential information. If you have received it 
> in error, please notify the sender immediately and delete the original. Any 
> other use of the e-mail by you is prohibited. Thank you in advance for your 
> cooperation.
>
> ________________________________




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