[SPARK-11227][CORE] UnknownHostException can be thrown when NameNode HA is enabled.

## What changes were proposed in this pull request?

If the following conditions are satisfied, executors don't load properties in `hdfs-site.xml` and UnknownHostException can be thrown.

(1) NameNode HA is enabled
(2) spark.eventLogging is disabled or logging path is NOT on HDFS
(3) Using Standalone or Mesos for the cluster manager
(4) There are no code to load `HdfsCondition` class in the driver regardless of directly or indirectly.
(5) The tasks access to HDFS

(There might be some more conditions...)

For example, following code causes UnknownHostException when the conditions above are satisfied.
```
sc.textFile("<path on HDFS>").collect

```

```
java.lang.IllegalArgumentException: java.net.UnknownHostException: hacluster
	at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:378)
	at org.apache.hadoop.hdfs.NameNodeProxies.createNonHAProxy(NameNodeProxies.java:310)
	at org.apache.hadoop.hdfs.NameNodeProxies.createProxy(NameNodeProxies.java:176)
	at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:678)
	at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:619)
	at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
	at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2653)
	at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:92)
	at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2687)
	at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2669)
	at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:371)
	at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:170)
	at org.apache.hadoop.mapred.JobConf.getWorkingDirectory(JobConf.java:656)
	at org.apache.hadoop.mapred.FileInputFormat.setInputPaths(FileInputFormat.java:438)
	at org.apache.hadoop.mapred.FileInputFormat.setInputPaths(FileInputFormat.java:411)
	at org.apache.spark.SparkContext$$anonfun$hadoopFile$1$$anonfun$32.apply(SparkContext.scala:986)
	at org.apache.spark.SparkContext$$anonfun$hadoopFile$1$$anonfun$32.apply(SparkContext.scala:986)
	at org.apache.spark.rdd.HadoopRDD$$anonfun$getJobConf$6.apply(HadoopRDD.scala:177)
	at org.apache.spark.rdd.HadoopRDD$$anonfun$getJobConf$6.apply(HadoopRDD.scala:177)
	at scala.Option.map(Option.scala:146)
	at org.apache.spark.rdd.HadoopRDD.getJobConf(HadoopRDD.scala:177)
	at org.apache.spark.rdd.HadoopRDD$$anon$1.<init>(HadoopRDD.scala:213)
	at org.apache.spark.rdd.HadoopRDD.compute(HadoopRDD.scala:209)
	at org.apache.spark.rdd.HadoopRDD.compute(HadoopRDD.scala:102)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:318)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:282)
	at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:318)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:282)
	at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:70)
	at org.apache.spark.scheduler.Task.run(Task.scala:85)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.UnknownHostException: hacluster
```

But following code doesn't cause the Exception because `textFile` method loads `HdfsConfiguration` indirectly.

```
sc.textFile("<path on HDFS>").collect
```

When a job includes some operations which access to HDFS, the object of `org.apache.hadoop.Configuration` is wrapped by `SerializableConfiguration`,  serialized and broadcasted from driver to executors and each executor deserialize the object with `loadDefaults` false so HDFS related properties should be set before broadcasted.

## How was this patch tested?
Tested manually on my standalone cluster.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #13738 from sarutak/SPARK-11227.

0 files changed, 0 insertions, 0 deletions