小编jua*_*011的帖子

给定一个已启动的具有内存限制的Docker 容器，我想知道是否可以检测到何时强制实施该内存限制，从而使该容器即将崩溃，因为它的内存不足。是否有一些我可以捕获的信号？或者我可以轮询一些日志文件？事后检测到这一点，即使延迟几分钟仍然有用

我开发了一个 ScalaCheck 属性来测试 Spark Streaming 转换。为此，我必须开发一个自定义的 InputDStream，它与 QueueInputDStream 非常相似，但有一个方法可以向 DStream 添加新的 dstream 测试用例，dstream 是 Seq[Seq[A]] 类型的对象。您可以在https://github.com/juanrh/sscheck/blob/32c2bff66aa5500182e0162a24ecca6d47707c42/src/main/scala/org/apache/spark/streaming/dstream/DynSeqQueueInputDStream.scala中查看代码。我开发了一些在本地模式下运行的属性https://github.com/juanrh/sscheck/blob/32c2bff66aa5500182e0162a24ecca6d47707c42/src/test/scala/es/ucm/fdi/sscheck/spark/streaming/ScalaCheckStreamingTest.scala。问题是，当批处理间隔太小时，并且机器无法足够快地完成批处理时，我在 Spark 日志中收到以下异常

15/08/26 11:22:02 ERROR JobScheduler: Error generating jobs for time 1440580922500 ms
java.lang.NullPointerException
    at org.apache.spark.streaming.dstream.DStream$$anonfun$count$1$$anonfun$apply$18.apply(DStream.scala:587)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$count$1$$anonfun$apply$18.apply(DStream.scala:587)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$transform$1$$anonfun$apply$21.apply(DStream.scala:654)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$transform$1$$anonfun$apply$21.apply(DStream.scala:654)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$transform$2$$anonfun$5.apply(DStream.scala:668)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$transform$2$$anonfun$5.apply(DStream.scala:666)
    at org.apache.spark.streaming.dstream.TransformedDStream.compute(TransformedDStream.scala:41)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1$$anonfun$apply$7.apply(DStream.scala:350)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1$$anonfun$apply$7.apply(DStream.scala:350)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1.apply(DStream.scala:349)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1.apply(DStream.scala:349)
    at org.apache.spark.streaming.dstream.DStream.createRDDWithLocalProperties(DStream.scala:399)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1.apply(DStream.scala:344)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1.apply(DStream.scala:342)
    at scala.Option.orElse(Option.scala:257)
    at org.apache.spark.streaming.dstream.DStream.getOrCompute(DStream.scala:339)
    at org.apache.spark.streaming.dstream.ShuffledDStream.compute(ShuffledDStream.scala:41)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1$$anonfun$apply$7.apply(DStream.scala:350)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1$$anonfun$apply$7.apply(DStream.scala:350)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1.apply(DStream.scala:349)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$getOrCompute$1$$anonfun$1.apply(DStream.scala:349) …