Hi!

I do slightly disagree with Timo. Custom memory management is always
useful, also in the Streaming API. It makes execution more robust.

If you use RocksDB as a state backend, you get memory management from
RocksDB - effectively all your program key/value state is off-heap.

Flink's own state backends have not yet implemented custom memory
management (it is quite a bit more complex in a true streaming environment
than in batch), but it will come as a feature (though not officially
tracked as a jira).

Stephan



On Thu, Dec 15, 2016 at 10:43 AM, Tao Meng <oatg...@gmail.com> wrote:

> Thanks a lot.
>
> On 12月 15 2016, at 5:39 δΈ‹εˆ, Timo Walther <twal...@apache.org> wrote:
>
>> Hi Tao,
>>
>> no, streaming jobs do not use managed memory yet. Managed memory is
>> useful for sorting, joining and grouping bounded data. Unbounded stream do
>> not need that.
>>
>> It could be used in the future e.g. to store state or for new operators,
>> but is this is not on the roadmap so far.
>>
>> Regards,
>> Timo
>>
>>
>> Am 15/12/16 um 10:30 schrieb Tao Meng:
>>
>> Hi all,
>>
>>   I have some questions about memory management in the Streaming mode.
>>
>>   Do the Streaming jobs use the memory management module ?
>> If they don't,  for what considerations do not ?  Because Data exchange
>> is too frequent ?
>> Is there a plan to let streaming job use it ?
>>
>> Thanks a lot.
>>
>>
>>

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