Hi, I actually ran into this problem again with a different algorithm :/ Same exception and it looks like getMatchFor() in CompactingHashTable returns a null record. Not sure why or why the annotation prevents this from happening. Any insight is highly welcome :-)
Shall I open an issue so that we don't forget about this? -Vasia. On 4 April 2015 at 14:44, Vasiliki Kalavri <vasilikikala...@gmail.com> wrote: > Hi Fabian, > > thanks for looking into this. > Let me know if there's anything I can do to help! > > Cheers, > V. > > On 3 April 2015 at 22:31, Fabian Hueske <fhue...@gmail.com> wrote: > >> Thanks for the nice setup! >> I could easily reproduce the exception you are facing. >> But that's the only good news so far :-( >> >> I checked the plans and both are valid and should compute the correct >> result for the program. >> The split-of solution set delta is required because the it needs to be >> repartitioned (without the annotation, the optimizer does not know that it >> is in fact already correctly partitioned). One thing that made me a bit >> suspicious is that the solution set delta partitioning is marked with a >> Pipeline-Breaker. The pipeline breaker shouldn't make a semantic >> difference, but I am not sure if it is really required and also that part >> of the codebase was recently worked on. >> >> So, a closer look and more debugging is necessary to figure out what not >> working correctly here... >> >> >> 2015-04-03 14:14 GMT+02:00 Vasiliki Kalavri <vasilikikala...@gmail.com>: >> >> > Hi Fabian, >> > >> > I am using the dblp co-authorship dataset from SNAP: >> > http://snap.stanford.edu/data/com-DBLP.html >> > I also pushed my slightly modified version of ConnectedComponents, here: >> > https://github.com/vasia/flink/tree/cc-test. It basically generates the >> > vertex dataset from the edges, so that you don't need to create it >> > separately. >> > The annotation that creates the error is in line #172. >> > >> > Thanks a lot :)) >> > >> > -Vasia. >> > >> > >> > On 3 April 2015 at 13:09, Fabian Hueske <fhue...@gmail.com> wrote: >> > >> > > That looks pretty much like a bug. >> > > >> > > As you said, fwd fields annotations are optional and may improve the >> > > performance of a program, but never change its semantics (if set >> > > correctly). >> > > >> > > I'll have a look at it later. >> > > Would be great if you could provide some data to reproduce the bug. >> > > On Apr 3, 2015 12:48 PM, "Vasiliki Kalavri" < >> vasilikikala...@gmail.com> >> > > wrote: >> > > >> > > > Hello to my squirrels, >> > > > >> > > > I've been getting a NullPointerException for a DeltaIteration >> program >> > I'm >> > > > trying to implement and I could really use your help :-) >> > > > It seems that some of the input Tuples of the Join operator that I'm >> > > using >> > > > to create the next workset / solution set delta are null. >> > > > It also seems that adding ForwardedFields annotations solves the >> issue. >> > > > >> > > > I managed to reproduce the behavior using the ConnectedComponents >> > > example, >> > > > by removing the "@ForwardedFieldsFirst("*")" annotation from >> > > > the ComponentIdFilter join. >> > > > The exception message is the following: >> > > > >> > > > Caused by: java.lang.NullPointerException >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.examples.java.graph.ConnectedComponents$ComponentIdFilter.join(ConnectedComponents.java:186) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.examples.java.graph.ConnectedComponents$ComponentIdFilter.join(ConnectedComponents.java:1) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.runtime.operators.JoinWithSolutionSetSecondDriver.run(JoinWithSolutionSetSecondDriver.java:198) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.runtime.operators.RegularPactTask.run(RegularPactTask.java:496) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.runtime.iterative.task.AbstractIterativePactTask.run(AbstractIterativePactTask.java:139) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.runtime.iterative.task.IterationIntermediatePactTask.run(IterationIntermediatePactTask.java:92) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.runtime.operators.RegularPactTask.invoke(RegularPactTask.java:362) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.flink.runtime.execution.RuntimeEnvironment.run(RuntimeEnvironment.java:217) >> > > > at java.lang.Thread.run(Thread.java:745) >> > > > >> > > > I get this error locally with any sufficiently big dataset (~10000 >> > > nodes). >> > > > When the annotation is in place, it works without problem. >> > > > I also generated the optimizer plans for the two cases: >> > > > - with annotation (working): >> > > > https://gist.github.com/vasia/4f4dc6b0cc6c72b5b64b >> > > > - without annotation (failing): >> > > > https://gist.github.com/vasia/086faa45b980bf7f4c09 >> > > > >> > > > After visualizing the plans, the main difference I see is that in >> the >> > > > working case, the next workset node and the solution set delta nodes >> > are >> > > > merged, while in the failing case they are separate. >> > > > >> > > > Shouldn't this work with and without annotation (but be more >> efficient >> > > with >> > > > the annotation in place)? Or am I missing something here? >> > > > >> > > > Thanks in advance for any help :)) >> > > > >> > > > Cheers, >> > > > - Vasia. >> > > > >> > > >> > >> > >
