scala> records.groupBy("name").count().write.trigger(ProcessingTime("30 seconds")).option("checkpointLocation", "file:///home/hadoop/jsoncheckpoint").startStream("file:///home/hadoop/jsonresult") org.apache.spark.sql.AnalysisException: Aggregations are not supported on streaming DataFrames/Datasets in Append output mode. Consider changing output mode to Update.; at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$.org$apache$spark$sql$catalyst$analysis$UnsupportedOperationChecker$$throwError(UnsupportedOperationChecker.scala:142) at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForStreaming$1.apply(UnsupportedOperationChecker.scala:59) at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForStreaming$1.apply(UnsupportedOperationChecker.scala:46) at org.apache.spark.sql.catalyst.trees.TreeNode.foreachUp(TreeNode.scala:125) at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$.checkForStreaming(UnsupportedOperationChecker.scala:46) at org.apache.spark.sql.ContinuousQueryManager.startQuery(ContinuousQueryManager.scala:190) at org.apache.spark.sql.DataFrameWriter.startStream(DataFrameWriter.scala:351) at org.apache.spark.sql.DataFrameWriter.startStream(DataFrameWriter.scala:279)
I brief the spark code, looks like there is no way to change output mode to Update?