Thanks a lot Devendra Tagare for the response.

What you said is very clear and understandable. But, wondering, I am NOT 
getting that partition level order!! My operator is processing the records in 
jumbled order rather than in sequence!
And, I am saying this because, I am generating timestamps upon tuple receipt 
and emitting that timestamp to my destination, which is clearly showing the 
records are receiving to operator in a shuffled order.

I get records at milli second level differences!! Will that be a problem ?


Regards,
Raja.

From: Devendra Tagare 
<[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Tuesday, June 7, 2016 at 7:12 PM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: kafka input is processing records in a jumbled order

Hi Raja,

When you apply ONE_TO_MANY partitioning scheme, one instance of the operator 
consumes from many partitions of a kafka topic.

When you look at the consumed data, all the events coming from a given 
partition would be ordered but there are no ordering guarantees across 
partitions since kafka does not guarantee that

eg : If 3 partitions of a topic p1,p2,p3 having 10 messages each are connected 
to one physical partition of the KafkaInputOperator , then the ordering 
guarantee of p1.1 to p1.10 is honored.ie<http://honored.ie> message 10 of p1 be 
consumed only after messages 1 through 9 are consumed but the operator could 
consumer messages in a order like p1.1,p2.1,p1.2,p1.3,p3.1,p2.2..... which 
still follows the guarantees per partition.

Thanks,
Dev

On Tue, Jun 7, 2016 at 5:00 PM, Raja.Aravapalli 
<[email protected]<mailto:[email protected]>> wrote:

Thanks for the response Thomas.

My quick doubt is..

I have around 30 partitions of kafka topic, And all of them have messages 
ordered at partition level.

So, when I consume those messages using single consumer[with ONE_TO_MANY 
strategy set], still the ordering doesn’t work ?


My messages in topic are guaranteed to be ordered at partition level.

Thanks a lot in advance for your response.


Regards,
Raja.

From: Thomas Weise <[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Tuesday, June 7, 2016 at 5:52 PM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: kafka input is processing records in a jumbled order

Raja,

Are you expecting ordering across multiple Kafka partitions?

All messages from a given Kafka partition are received by the same consumer and 
thus will be ordered. However, when messages come from multiple partitions 
there is no such guarantee.

Thomas


On Tue, Jun 7, 2016 at 3:34 PM, Raja.Aravapalli 
<[email protected]<mailto:[email protected]>> wrote:

Hi

I have built a DAG, that reads from kafka and in the next operators, does 
lookup to a hbase table and update hbase table based on some business logic.

Some times my operator which does hbase lookup and update in the same 
operator(Custom written), is processing the records it receives from kafka in a 
jumbled order, which is causing, many records being ignored from processing!!

I am not using any parallel partitions/instance, and with KafkaInputOperator I 
am using only partition strategy ONE_TO_MANY.

I am very new to Apex. I expected, Apex will guarantee the ordering.

Can someone pls share your knowledge on the issue…?


Thanks a lot in advance…


Regards,
Raja.


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