This is actually a problem of the number of memory segments available to
the hash table for the solution set.

For complex pipelines, memory currently gets too fragmented.

There are two workarounds, until we do the dynamic memory management, or
break it into shorter pipelines: Break the job up into subparts, or move
the solution set to the user code part of the heap. There is a flag to
attach to the Delta Iterations, see
"DeltaIteration#setSolutionSetUnManaged()"

Greetinigs,
Stephan


On Mon, Feb 9, 2015 at 10:32 AM, Till Rohrmann <trohrm...@apache.org> wrote:

> Hi Andra,
>
> have you tried increasing the number of network buffers in your cluster?
> You can control by the configuration value:
>
> taskmanager.network.numberOfBuffers: #numberBuffers
>
> Greets,
>
> Till
>
> On Mon, Feb 9, 2015 at 9:56 AM, Andra Lungu <lungu.an...@gmail.com> wrote:
>
> > Hello everyone,
> >
> > I am implementing a graph algorithm as part of a course and I will also
> add
> > it to the Flink- Gelly examples.
> > My problem is that I started developing it in the Gelly repository, which
> > runs on flink 0.9. It works like a charm there, but in order to test in
> on
> > a cluster to see its real capabilities, I need to move it to the course
> > repository, which runs on flink 0.8.
> >
> > Initially, I thought this migration should occur without incidents since
> > flink 0.8 is more stable. Instead, I got the following exception:
> > java.lang.IllegalArgumentException: *Too few memory segments provided.
> Hash
> > Table needs at least 33 memory segments.*
> >     at
> >
> >
> org.apache.flink.runtime.operators.hash.CompactingHashTable.<init>(CompactingHashTable.java:238)
> >     at
> >
> >
> org.apache.flink.runtime.operators.hash.CompactingHashTable.<init>(CompactingHashTable.java:227)
> >     at
> >
> >
> org.apache.flink.runtime.iterative.task.IterationHeadPactTask.initCompactingHashTable(IterationHeadPactTask.java:177)
> >     at
> >
> >
> org.apache.flink.runtime.iterative.task.IterationHeadPactTask.run(IterationHeadPactTask.java:279)
> >     at
> >
> >
> org.apache.flink.runtime.operators.RegularPactTask.invoke(RegularPactTask.java:360)
> >     at
> >
> >
> org.apache.flink.runtime.execution.RuntimeEnvironment.run(RuntimeEnvironment.java:257)
> >     at java.lang.Thread.run(Thread.java:745)
> >
> > This is the code for Gelly, where all tests pass:
> > https://github.com/andralungu/flink-graph/tree/minSpanningTree
> > Unfortunately, the code for the course is private, so you cannot actually
> > see it... maybe @aalexandrov can do something about the privacy settings
> of
> > this repo.
> > https://github.com/andralungu/IMPRO-3.WS14/tree/dmst_algorithm
> >
> > Thank you!
> > Andra
> >
>

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