当我以纱线模式（spark版本2.2.0）在Spark集群上运行Scala应用程序时，该应用程序使用的是pregel模型，数据图中的每个顶点都会发送消息。异常信息如下：
Exception in thread "main" org.apache.spark.SparkException:
Job aborted due to stage failure: Task 29 in stage 25.0 failed 4 times,
most recent failure: Lost task 29.3 in stage 25.0 (TID 1632, 192.168.1.5, executor 1): java.io.IOException: org.apache.spark.SparkException:
Failed to get broadcast_22_piece0 of broadcast_22
at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1310)
at org.apache.spark.broadcast.TorrentBroadcast.readBroadcastBlock(TorrentBroadcast.scala:206)
at org.apache.spark.broadcast.TorrentBroadcast._value$lzycompute(TorrentBroadcast.scala:66)
at org.apache.spark.broadcast.TorrentBroadcast._value(TorrentBroadcast.scala:66)
at org.apache.spark.broadcast.TorrentBroadcast.getValue(TorrentBroadcast.scala:96)
at org.apache.spark.broadcast.Broadcast.value(Broadcast.scala:70)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:86)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:53)
at org.apache.spark.scheduler.Task.run(Task.scala:108)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:335)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.spark.SparkException: Failed to get broadcast_22_piece0 of broadcast_22
at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1.apply$mcVI$sp(TorrentBroadcast.scala:178)
at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1.apply(TorrentBroadcast.scala:150)
at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1.apply(TorrentBroadcast.scala:150)
at scala.collection.immutable.List.foreach(List.scala:381)
at org.apache.spark.broadcast.TorrentBroadcast.org$apache$spark$broadcast$TorrentBroadcast$$readBlocks(TorrentBroadcast.scala:150)
at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$readBroadcastBlock$1.apply(TorrentBroadcast.scala:222)
at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1303)
... 12 more
我已在线搜索了异常，建议之一是添加语句.set("spark.cleaner.ttl","2000")
但是它仍然不能很好地工作。
你能帮助我吗？非常感谢。
一些可能导致上述异常的罪魁祸首如下：
val spark = SparkSession.builder.master("spark://node01.:7077").appName("ioce").getOrCreate()
.......
and in the program, joinning dataframe is used(which I looked through online warns that may be also relevant to the exception).