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From Hequn Cheng <chenghe...@gmail.com>
Subject Re: Order of events in a Keyed Stream
Date Sun, 29 Jul 2018 03:01:51 GMT
Hi harshvardhan,
If 1.the messages exist on the same topic and 2.there are no rebalance and
3.keyby on the same field with same value, the answer is yes.

Best, Hequn

On Sun, Jul 29, 2018 at 3:56 AM, Harshvardhan Agrawal <
harshvardhan.agr93@gmail.com> wrote:

> Hey,
>
> The messages will exist on the same topic. I intend to keyby on the same
> field. The question is that will the two messages be mapped to the same
> task manager and on the same slot. Also will they be processed in correct
> order given they have the same keys?
>
> On Fri, Jul 27, 2018 at 21:28 Hequn Cheng <chenghequn@gmail.com> wrote:
>
>> Hi Harshvardhan,
>>
>> There are a number of factors to consider.
>> 1. the consecutive Kafka messages must exist in a same topic of kafka.
>> 2. the data should not been rebalanced. For example, operators should be
>> chained in order to avoid rebalancing.
>> 3. if you perform keyBy(), you should keyBy on a field the consecutive
>> two messages share the same value.
>>
>> Best, Hequn
>>
>> On Sat, Jul 28, 2018 at 12:11 AM, Harshvardhan Agrawal <
>> harshvardhan.agr93@gmail.com> wrote:
>>
>>> Hi,
>>>
>>>
>>> We are currently using Flink to process financial data. We are getting
>>> position data from Kafka and we enrich the positions with account and
>>> product information. We are using Ingestion time while processing events.
>>> The question I have is: say I key the position datasream by account number.
>>> If I have two consecutive Kafka messages with the same account and product
>>> info where the second one is an updated position of the first one, does
>>> Flink guarantee that the messages will be processed on the same slot in the
>>> same worker? We want to ensure that we don’t process them out of order.
>>>
>>> Thank you!
>>> --
>>> Regards,
>>> Harshvardhan
>>>
>>
>> --
> Regards,
> Harshvardhan
>

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