1.现象
flume使用pull方式整合Streaming，参考官网http://spark.apache.org/docs/2.1.0/streaming-flume-integration.html，配置好flume以及编写好streaming 程序后，发现使用telnet发送数据，报错：
2018-09-20 06:30:33,384 (Spark Sink Processor Thread - 8) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:80)] Error while processing transaction.
java.lang.IllegalStateException: begin() called when transaction is OPEN!
at com.google.common.base.Preconditions.checkState(Preconditions.java:145)
at org.apache.flume.channel.BasicTransactionSemantics.begin(BasicTransactionSemantics.java:131)
at org.apache.spark.streaming.flume.sink.TransactionProcessor$$anonfun$populateEvents$1.apply(TransactionProcessor.scala:114)
at org.apache.spark.streaming.flume.sink.TransactionProcessor$$anonfun$populateEvents$1.apply(TransactionProcessor.scala:113)
at scala.Option.foreach(Option.scala:236)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.populateEvents(TransactionProcessor.scala:113)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.call(TransactionProcessor.scala:243)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.call(TransactionProcessor.scala:43)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
2018-09-20 06:30:33,385 (Spark Sink Processor Thread - 8) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Spark was unable to successfully process the events. Transaction is being rolled back.
2018-09-20 06:30:33,385 (New I/O worker #1) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Received an error batch - no events were received from channel!
2018-09-20 06:30:33,389 (New I/O worker #1) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Received an error batch - no events were received from channel!
2018-09-20 06:30:33,391 (New I/O worker #1) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Received an error batch - no events were received from channel!
2018-09-20 06:30:33,394 (Spark Sink Processor Thread - 9) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:80)] Error while processing transaction.
java.lang.IllegalStateException: begin() called when transaction is OPEN!
at com.google.common.base.Preconditions.checkState(Preconditions.java:145)
at org.apache.flume.channel.BasicTransactionSemantics.begin(BasicTransactionSemantics.java:131)
at org.apache.spark.streaming.flume.sink.TransactionProcessor$$anonfun$populateEvents$1.apply(TransactionProcessor.scala:114)
at org.apache.spark.streaming.flume.sink.TransactionProcessor$$anonfun$populateEvents$1.apply(TransactionProcessor.scala:113)
at scala.Option.foreach(Option.scala:236)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.populateEvents(TransactionProcessor.scala:113)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.call(TransactionProcessor.scala:243)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.call(TransactionProcessor.scala:43)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
2018-09-20 06:30:33,395 (Spark Sink Processor Thread - 9) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Spark was unable to successfully process the events. Transaction is being rolled back.
2018-09-20 06:30:33,397 (New I/O worker #1) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Received an error batch - no events were received from channel!
2018-09-20 06:30:33,403 (Spark Sink Processor Thread - 10) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:80)] Error while processing transaction.
java.lang.IllegalStateException: begin() called when transaction is OPEN!
at com.google.common.base.Preconditions.checkState(Preconditions.java:145)
at org.apache.flume.channel.BasicTransactionSemantics.begin(BasicTransactionSemantics.java:131)
at org.apache.spark.streaming.flume.sink.TransactionProcessor$$anonfun$populateEvents$1.apply(TransactionProcessor.scala:114)
at org.apache.spark.streaming.flume.sink.TransactionProcessor$$anonfun$populateEvents$1.apply(TransactionProcessor.scala:113)
at scala.Option.foreach(Option.scala:236)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.populateEvents(TransactionProcessor.scala:113)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.call(TransactionProcessor.scala:243)
at org.apache.spark.streaming.flume.sink.TransactionProcessor.call(TransactionProcessor.scala:43)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
2018-09-20 06:30:33,403 (Spark Sink Processor Thread - 10) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Spark was unable to successfully process the events. Transaction is being rolled back.
2018-09-20 06:30:33,406 (New I/O worker #1) [WARN - org.apache.spark.streaming.flume.sink.Logging$class.logWarning(Logging.scala:59)] Received an error batch - no events were received from channel!
2.原因
（1）没有按照官网要求把flume需要的包，放到flume的lib下面
（2）flume的lib下面由两个scala-library，一个2.10.1一个2.11.8，所以要重命名或者删除下2.10.1，否则会引起歧义
3.解决
（1）自己偷懒，只是把scala-library-2.11.8.jar包拷贝到lib目录下，并且把scala-library-2.10.1.jar修改为scala-library-2.10.1.jarss
