Hey guys, I'd like to offer some input.
The test also fails locally on my Mac with the following error. (so
WriteOperation#finalize is not called)
java.lang.NullPointerException
at com.datatorrent.netlet.util.Slice.<init>(Slice.java:54)
at
org.apache.beam.runners.apex.translation.utils.ApexStateInternals$ApexStateInternalsFactory.stateInternalsForKey(ApexStateInternals.java:449)
The error is in the following line, where `Slice` takes a null value when
the `key` is null
keyBytes = (key != null) ? new
Slice(CoderUtils.encodeToByteArray(keyCoder, key)) :
new Slice(null);
while it doesn't look right from its constructor (array can not be null).
public Slice(byte[] array) {
this.buffer = array;
this.offset = 0;
this.length = array.length;
}
On Fri, Jul 7, 2017 at 4:35 AM Reuven Lax <re...@google.com.invalid> wrote:
> Thomas, any suggestions on what we should do? Do you have an idea what's
> going on, or should we exclude this test for now until you have time to
> look at it?
>
> Reuven
>
> On Wed, Jul 5, 2017 at 3:36 PM, Reuven Lax <re...@google.com> wrote:
>
> > I wonder if the watermark is accidentally advancing too early, causing
> > Apex to shut down the pipeline before the final finalize DoFn executes?
> >
> > On Wed, Jul 5, 2017 at 1:45 PM, Thomas Weise <t...@apache.org> wrote:
> >
> >> I don't think this is a problem with the test and if anything this
> problem
> >> to me shows the test is useful in catching similar issues during unit
> test
> >> runs.
> >>
> >> Is there any form of asynchronous/trigger based processing in this
> >> pipeline
> >> that could cause this?
> >>
> >> The Apex runner will shutdown the pipeline after the final watermark,
> the
> >> shutdown signal traverses the pipeline just like a watermark, but it is
> >> not
> >> seen by user code.
> >>
> >> Thomas
> >>
> >> --
> >> sent from mobile
> >> On Jul 5, 2017 1:19 PM, "Kenneth Knowles" <k...@google.com.invalid>
> wrote:
> >>
> >> > Upon further investigation, this tests always writes to
> >> > ./target/wordcountresult-00000-of-00002 and
> >> > ./target/wordcountresult-00001-of-00002. So after a successful test
> >> run,
> >> > any further run without a `clean` will spuriously succeed. I was
> running
> >> > via IntelliJ so did not do the ritual `mvn clean` workaround. So
> >> > reproduction appears to be easy and we could fix the test (if we don't
> >> > remove it) to use a fresh temp dir.
> >> >
> >> > This seems to point to a bug in waitUntilFinish() and/or Apex if the
> >> > topology is shut down before this ParDo is run. This is a ParDo with
> >> > trivial bounded input but with side inputs. So I would guess the bug
> is
> >> > either in watermark tracking / readiness of the side input or just how
> >> > PushbackSideInputDoFnRunner is used.
> >> >
> >> > On Wed, Jul 5, 2017 at 12:23 PM, Reuven Lax <re...@google.com.invalid
> >
> >> > wrote:
> >> >
> >> > > I've done a bit more debugging with logging. It appears that the
> >> finalize
> >> > > ParDo is never being invoked in this Apex test (or at least the
> >> LOG.info
> >> > in
> >> > > that ParDo never runs). This ParDo is run on a constant element
> (code
> >> > > snippet below), so it should always run.
> >> > >
> >> > > PCollection<Void> singletonCollection = p.apply(Create.of((Void)
> >> null));
> >> > > singletonCollection
> >> > > .apply("Finalize", ParDo.of(new DoFn<Void, Integer>() {
> >> > > @ProcessElement
> >> > > public void processElement(ProcessContext c) throws Exception
> {
> >> > > LOG.info("Finalizing write operation {}.", writeOperation);
> >> > >
> >> > >
> >> > > On Wed, Jul 5, 2017 at 11:22 AM, Kenneth Knowles
> >> <k...@google.com.invalid
> >> > >
> >> > > wrote:
> >> > >
> >> > > > Data-dependent file destinations is a pretty great feature. We
> also
> >> > have
> >> > > > another change to make to this @Experimental feature, and it would
> >> be
> >> > > nice
> >> > > > to get them both into 2.1.0 if we can unblock this quickly.
> >> > > >
> >> > > > I just tried this too, and failed to reproduce it. But Jenkins and
> >> > Reuven
> >> > > > both have a reliable repro.
> >> > > >
> >> > > > Questionss:
> >> > > >
> >> > > > - Any ideas about how these configurations differ?
> >> > > > - Does this actually affect users?
> >> > > > - Once we have another test that catches this issue, can we
> delete
> >> > this
> >> > > > test?
> >> > > >
> >> > > > Every other test passes, including the actual example WordCountIT.
> >> > Since
> >> > > > the PR doesn't change primitives, it also seems like it is an
> >> existing
> >> > > > issue. And the test seems redundant with our other testing but
> won't
> >> > get
> >> > > as
> >> > > > much maintenance attention. I don't want to stop catching whatever
> >> this
> >> > > > issue is, though.
> >> > > >
> >> > > > Kenn
> >> > > >
> >> > > > On Wed, Jul 5, 2017 at 10:31 AM, Reuven Lax
> >> <re...@google.com.invalid>
> >> > > > wrote:
> >> > > >
> >> > > > > Hi Thomas,
> >> > > > >
> >> > > > > This only happens with https://github.com/apache/beam/pull/3356
> .
> >> > > > >
> >> > > > > Reuven
> >> > > > >
> >> > > > > On Mon, Jul 3, 2017 at 6:11 AM, Thomas Weise <t...@apache.org>
> >> wrote:
> >> > > > >
> >> > > > > > Hi Reuven,
> >> > > > > >
> >> > > > > > I'm not able to reproduce the issue locally. I was hoping to
> see
> >> > > which
> >> > > > > > thread is attempting to emit the results. In Apex, only the
> >> > operator
> >> > > > > thread
> >> > > > > > can emit the results, any other thread that is launched by the
> >> > > operator
> >> > > > > > cannot. I'm not aware of ParDo managing separate threads
> though
> >> and
> >> > > > > assume
> >> > > > > > this must be a race. If you still have the log, can you send
> it
> >> to
> >> > > me?
> >> > > > > >
> >> > > > > > Thanks,
> >> > > > > > Thomas
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > > On Sat, Jul 1, 2017 at 5:51 AM, Reuven Lax
> >> > <re...@google.com.invalid
> >> > > >
> >> > > > > > wrote:
> >> > > > > >
> >> > > > > > > pr/3356 fails in the Apex WordCountTest. The failed test is
> >> here
> >> > > > > > > <https://builds.apache.org/job/beam_PreCommit_Java_
> >> > > > > > > MavenInstall/12829/org.apache.beam$beam-runners-apex/
> >> > > > > > > testReport/org.apache.beam.runners.apex.examples/WordCountTe
> >> st/
> >> > > > > > > testWordCountExample/>
> >> > > > > > > :
> >> > > > > > >
> >> > > > > > > Upon debugging, it looks like this is likely a problem in
> the
> >> > Apex
> >> > > > > runner
> >> > > > > > > itself. A ParDo calls output(), and that triggers an
> exception
> >> > > thrown
> >> > > > > > from
> >> > > > > > > inside the Apex runner. The Apex runner calls emit on a
> >> > > > > DefaultOutputPort
> >> > > > > > > (ApexParDoOperator.java:275), and that throws an exception
> >> inside
> >> > > of
> >> > > > > > > verifyOperatorThread().
> >> > > > > > >
> >> > > > > > > I'm going to ignore this failure for now as it seems
> >> unrelated to
> >> > > my
> >> > > > > PR,
> >> > > > > > > but does someone want to take a look?
> >> > > > > > >
> >> > > > > > > Reuven
> >> > > > > > >
> >> > > > > >
> >> > > > >
> >> > > >
> >> > >
> >> >
> >>
> >
> >
>
