Hi, I want to do some simple aggregations on 727 gz files (68 GB total) from HDFS. See code here:
https://github.com/FelixNeutatz/wikiTrends/blob/master/extraction/src/main/scala/io/sanfran/wikiTrends/extraction/flink/Stats.scala We are using a Flink-0.9 SNAPSHOT. I get the following error: Caused by: java.lang.Exception: The data preparation for task 'Reduce(Reduce at org.apache.flink.api.scala.GroupedDataSet.reduce(GroupedDataSet.scala:293))' , caused an e rror: Error obtaining the sorted input: Thread 'SortMerger spilling thread' terminated due to an exception: Channel to path '/data/4/hadoop/tmp/flink-io-0e2460bf-964b-488 3-8eee-12869b9476ab/995a38a2c92536383d0057e3482999a9.000329.channel' could not be opened. at org.apache.flink.runtime.operators.RegularPactTask.run(RegularPactTask.java:471) at org.apache.flink.runtime.operators.RegularPactTask.invoke(RegularPactTask.java:362) at org.apache.flink.runtime.taskmanager.Task.run(Task.java:559) at java.lang.Thread.run(Thread.java:853) Caused by: java.lang.RuntimeException: Error obtaining the sorted input: Thread 'SortMerger spilling thread' terminated due to an exception: Channel to path '/data/4/hado op/tmp/flink-io-0e2460bf-964b-4883-8eee-12869b9476ab/995a38a2c92536383d0057e3482999a9.000329.channel' could not be opened. at org.apache.flink.runtime.operators.sort.UnilateralSortMerger.getIterator(UnilateralSortMerger.java:607) at org.apache.flink.runtime.operators.RegularPactTask.getInput(RegularPactTask.java:1145) at org.apache.flink.runtime.operators.ReduceDriver.prepare(ReduceDriver.java:93) at org.apache.flink.runtime.operators.RegularPactTask.run(RegularPactTask.java:466) ... 3 more Caused by: java.io.IOException: Thread 'SortMerger spilling thread' terminated due to an exception: Channel to path '/data/4/hadoop/tmp/flink-io-0e2460bf-964b-4883-8eee-1 2869b9476ab/995a38a2c92536383d0057e3482999a9.000329.channel' could not be opened. at org.apache.flink.runtime.operators.sort.UnilateralSortMerger$ThreadBase.run(UnilateralSortMerger.java:784) Caused by: java.io.IOException: Channel to path '/data/4/hadoop/tmp/flink-io-0e2460bf-964b-4883-8eee-12869b9476ab/995a38a2c92536383d0057e3482999a9.000329.channel' could n ot be opened. at org.apache.flink.runtime.io.disk.iomanager.AbstractFileIOChannel.<init>(AbstractFileIOChannel.java:61) at org.apache.flink.runtime.io.disk.iomanager.AsynchronousFileIOChannel.<init>(AsynchronousFileIOChannel.java:86) at org.apache.flink.runtime.io.disk.iomanager.AsynchronousBlockWriterWithCallback.<init>(AsynchronousBlockWriterWithCallback.java:42) at org.apache.flink.runtime.io.disk.iomanager.AsynchronousBlockWriter.<init>(AsynchronousBlockWriter.java:44) at org.apache.flink.runtime.io.disk.iomanager.IOManagerAsync.createBlockChannelWriter(IOManagerAsync.java:195) at org.apache.flink.runtime.io.disk.iomanager.IOManager.createBlockChannelWriter(IOManager.java:218) at org.apache.flink.runtime.operators.sort.UnilateralSortMerger$SpillingThread.go(UnilateralSortMerger.java:1318) at org.apache.flink.runtime.operators.sort.UnilateralSortMerger$ThreadBase.run(UnilateralSortMerger.java:781) Caused by: java.io.FileNotFoundException: /data/4/hadoop/tmp/flink-io-0e2460bf-964b-4883-8eee-12869b9476ab/995a38a2c92536383d0057e3482999a9.000329.channel (Too many open files in system) at java.io.RandomAccessFile.<init>(RandomAccessFile.java:252) at java.io.RandomAccessFile.<init>(RandomAccessFile.java:133) at org.apache.flink.runtime.io.disk.iomanager.AbstractFileIOChannel.<init>(AbstractFileIOChannel.java:57) ... 7 more Best regards, Felix
