Re: How to distribute subtasks evenly across taskmanagers?

2018-12-05 Thread Till Rohrmann
Hi Sunny,

this is a current limitation of Flink's scheduling. We are currently
working on extending Flinks scheduling mechanism [1] which should also help
with solving this problem. At the moment, I recommend using the per-job
mode so that you have a single cluster per job.

[1] https://issues.apache.org/jira/browse/FLINK-10407

Cheers,
Till

On Wed, Dec 5, 2018 at 2:07 AM Sunny Yun  wrote:

> Why does Flink do resource management by only slots, not by TaskManagers
> and slots?
>
> If there are one Flink cluster to submit multiple jobs, how do I make
> JobManager to distribute subtasks evenly to all TaskManagers?
> Now, JobManager treats the slots globally, some jobs' operators are
> assigned only one TM's slots.
>
>
> For example:
>
> 3 TaskManager (taskmanager.numberOfTaskSlots: 8) = total 24 slots
>
> env
> .setParallelism(6)
> .addSource(sourceFunction)
> .partitionCustom(partitioner, keySelector)
> .map(mapper)
> .addSink(sinkFunction);
> env.execute(job1);
>
> env
> .setParallelism(12)
> .addSource(sourceFunction)
> .partitionCustom(partitioner, keySelector)
> .map(mapper)
> .addSink(sinkFunction);
> env.execute(job2);
>
> env
> .setParallelism(6)
> .addSource(sourceFunction)
> .partitionCustom(partitioner, keySelector)
> .map(mapper)
> .addSink(sinkFunction);
> env.execute(job3);
>
>
> Intented :
> TM1 TM2 TM3
>--
> job1-source 2   2   2
> job1-map-sink   2   2   2
> job2-source 4   4   4
> job2-map-sink   4   4   4
> job3-source 2   2   2
> job3-map-sink   2   2   2
>
>
> Because each job is under the stress at unpredictable time, it is
> important to use all available resource per each job.
> We made three clusters (6, 6, 12 each total slots) as a temporary, but
> it's not pretty way.
>
>
> Best, Sunny
> ᐧ
>


How to distribute subtasks evenly across taskmanagers?

2018-12-04 Thread Sunny Yun
Why does Flink do resource management by only slots, not by TaskManagers
and slots?

If there are one Flink cluster to submit multiple jobs, how do I make
JobManager to distribute subtasks evenly to all TaskManagers?
Now, JobManager treats the slots globally, some jobs' operators are
assigned only one TM's slots.


For example:

3 TaskManager (taskmanager.numberOfTaskSlots: 8) = total 24 slots

env
.setParallelism(6)
.addSource(sourceFunction)
.partitionCustom(partitioner, keySelector)
.map(mapper)
.addSink(sinkFunction);
env.execute(job1);

env
.setParallelism(12)
.addSource(sourceFunction)
.partitionCustom(partitioner, keySelector)
.map(mapper)
.addSink(sinkFunction);
env.execute(job2);

env
.setParallelism(6)
.addSource(sourceFunction)
.partitionCustom(partitioner, keySelector)
.map(mapper)
.addSink(sinkFunction);
env.execute(job3);


Intented :
TM1 TM2 TM3
   --
job1-source 2   2   2
job1-map-sink   2   2   2
job2-source 4   4   4
job2-map-sink   4   4   4
job3-source 2   2   2
job3-map-sink   2   2   2


Because each job is under the stress at unpredictable time, it is important
to use all available resource per each job.
We made three clusters (6, 6, 12 each total slots) as a temporary, but it's
not pretty way.


Best, Sunny
ᐧ