Hi Martin, Great. Thanks for the fix!
Cheers, Max On Tue, Nov 24, 2015 at 7:40 PM, Martin Junghanns <m.jungha...@mailbox.org> wrote: > Hi Max, > > fixed in https://github.com/apache/flink/pull/1396 > > Best, > Martin > > > On 24.11.2015 13:46, Maximilian Michels wrote: >> >> Hi André, hi Martin, >> >> This looks very much like a bug. Martin, I would be happy if you >> opened a JIRA issue. >> >> Thanks, >> Max >> >> On Sun, Nov 22, 2015 at 12:27 PM, Martin Junghanns >> <m.jungha...@mailbox.org> wrote: >>> >>> Hi, >>> >>> What he meant was MultipleProgramsTestBase, not FlinkTestBase. >>> >>> I debugged this a bit. >>> >>> The NPE is thrown in >>> >>> >>> https://github.com/apache/flink/blob/master/flink-java/src/main/java/org/apache/flink/api/java/operators/AggregateOperator.java#L296 >>> >>> since current can be null if the input iterator is empty. >>> >>> In Cluster Execution, it is checked that the output of the previous >>> function >>> (e.g. Filter) is not empty in: >>> >>> >>> https://github.com/apache/flink/blob/master/flink-runtime/src/main/java/org/apache/flink/runtime/operators/AllGroupReduceDriver.java#L144 >>> >>> which avoids going into AggregateOperator and getting a NPE. >>> >>> However, in Collection Mode, the execution is not grouped (don't know >>> why, >>> yet). In >>> >>> >>> https://github.com/apache/flink/blob/master/flink-core/src/main/java/org/apache/flink/api/common/operators/base/GroupReduceOperatorBase.java#L207 >>> >>> the copied input data is handed over to the aggregate function which >>> leads >>> to the NPE. >>> >>> Checking inputDataCopy.size() > 0 before calling the aggregate solves the >>> problem. >>> >>> If someone can confirm that this is not a more generic problem, I would >>> open >>> an issue and a PR. >>> >>> Best, >>> Martin >>> >>> >>> On 20.11.2015 18:41, André Petermann wrote: >>>> >>>> >>>> Hi all, >>>> >>>> during a workflow, a data set may run empty, e.g., because of a join >>>> without matches. >>>> >>>> We're using FlinkTestBase and found out, that aggregate functions on >>>> empty data sets work fine in CLUSTER execution mode but cause a Null >>>> Pointer Exception at AggregateOperator$AggregatingUdf in COLLECTION >>>> mode. >>>> >>>> Here is the minimal example on 1.0-SNAPSHOT: >>>> https://gist.github.com/p3et/59a65bab11098dd11054 >>>> >>>> Are we doing something wrong, or is this a bug? >>>> >>>> Cheers, >>>> Andre >>>> >>> >
