We know, kylin builds dimension dictionary in kylin job client. But if a cube has uhc dimensions, it will cost much more CPU and memory resources. Kylin provides the ability to build uhc dictionary using the MR engine to reduce the resource consumption of the build engine.
But I find that the "Build UHC Dictionary" step build error. This step run using MR engine. This is the error info from yarn:
org.apache.hadoop.mapred.YarnChild: Exception running child : java.io.IOException: hdfs://hacluster/xxx.../xxx/fact_distinct_columns/xxx/FIELD_NAME.dic-r-00001 not a SequenceFile.
The reason of this problem is that the "Extract Fact Table Distinct " step output two type of files:".dci" and ".rldict"; but the ".dci" file is not a sequence file, so the "Build UHC Dictionary" step should filter ".dci" file when run with MR engine.
I resolve this problem and will summit my code.