flink-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Sowmya Vallabhajosyula <sowmy...@zemosolabs.com>
Subject Re: Clear irrelevant state values
Date Mon, 25 Apr 2016 13:15:59 GMT
Thanks Gyula.

Yes, I am using state only in RichFlatMapFunction. Will try to evaluate
generating events for removal of state.


On Mon, Apr 25, 2016 at 5:44 PM, Gyula Fóra <gyula.fora@gmail.com> wrote:

> Hi,
> The removal markers are just something I made up :) What I meant is that
> you can generate events in a custom source for instance that will trigger
> the removal of the state. This might be easy or hard to do depending on
> your use-case.
> What do you mean by custom state maintenance? As long as you are using the
> state interfaces correctly in your functions you should be fine in terms of
> scalability.
> Gyula
> Sowmya Vallabhajosyula <sowmya.v@zemosolabs.com> ezt írta (időpont: 2016.
> ápr. 25., H, 13:29):
>> Hi Gyula,
>> Thank you so much.
>> 1. Can you point me to any documentation on removal markers?
>> 2. My understanding is this implementation of custom state maintenance
>> does not impact scalabiity. Is that right?
>> Thanks,
>> Sowmya
>> On Mon, Apr 25, 2016 at 3:06 PM, Gyula Fóra <gyfora@apache.org> wrote:
>>> Hi,
>>> (a) I think your understanding is correct, one consideration might be
>>> that if you are always sending the state to the sink, it might make sense
>>> to build it there directly using a RichSinkFunction.
>>> (b) There is no built-in support for this at the moment. What you can do
>>> yourself is to generate removal markers for the patients automatically. We
>>> could probably add this feature later which might be easier to implement
>>> for some state backends. For instance in RocksDB we could use a
>>> time-to-live database to remove states after a given period.
>>> Cheers,
>>> Gyula
>>> Sowmya Vallabhajosyula <sowmya.v@zemosolabs.com> ezt írta (időpont:
>>> 2016. ápr. 25., H, 11:22):
>>>> Hi,
>>>> Scenario: Health care where a list of patient events are flowing in. We
>>>> would like to keep a Value / List state holding all events and updating the
>>>> state based on a set of business rules. For e.g. if 4 vitals exceed range
>>>> in 24 hours, state is sirs. If the patient is in sirs state and a source
>>>> infection is reported now, update state to sepsis. Attached flow for your
>>>> reference.
>>>> Considering the example of RideSource, if I use a RichFlatMapFunction
>>>> to maintain this state (please let me know if this doesn't make sense),
>>>> (a) out.collect will return the current patient state to a sink so at
>>>> the end of every event, we know the state of the patient at this instance.
>>>> Is my understanding right?
>>>> (b) Let's say after x days, these events that we recorded are not valid
>>>> anymore. How do we clear the state?
>>>> --
>>>> Thanks and Regards,
>>>> Sowmya Vallabhajosyula
>> --
>> Thanks and Regards,
>> Sowmya Vallabhajosyula

Thanks and Regards,
Sowmya Vallabhajosyula

View raw message