KYLIN-5539 need close FSDataInputStream

[liuzhao-lz]

Proposed changes

1.初始发现：线上告警某节点存在大量的CLOSE_WAIT，通过 netstat -anp 发现来自于Kylin4 JobServer 进程，CLOSE_WAIT数达到9000多。并且 CLOSE_WAIT 来自的外部地址端口都是 50010，而该端口是 Hadoop DataNode 数据传输使用，故此怀疑是 JobServer在每次作业构建时 fileSystem.open() 一个流后没有进行close。
2.模拟复现：在研测环境提交cube构建任务，并观察 CLOSE_WAIT 数及增长情况，发现每次cube构建结束后，CLOSE_WAIT 数增加1，至此可以确定是JobServer代码中未关闭流导致。
3.定位代码：深入kylin4 构建代码进行debug，最终定位到 org.apache.kylin.engine.spark.utils.UpdateMetadataUtil#syncLocalMetadataToRemote 94行 （Apache Kylin main分支）

String resKey = toUpdateSeg.getStatisticsResourcePath();
String statisticsDir = config.getJobTmpDir(currentInstanceCopy.getProject()) + "/"

• nsparkExecutable.getParam(MetadataConstants.P_JOB_ID) + "/" + ResourceStore.CUBE_STATISTICS_ROOT + "/"
• cubeId + "/" + segmentId + "/";
  Path statisticsFile = new Path(statisticsDir, BatchConstants.CFG_STATISTICS_CUBOID_ESTIMATION_FILENAME);
  FileSystem fs = HadoopUtil.getWorkingFileSystem();
  if (fs.exists(statisticsFile)) {
  FSDataInputStream is = fs.open(statisticsFile); //未关闭流
  ResourceStore.getStore(config).putBigResource(resKey, is, System.currentTimeMillis());
  }

CubeUpdate update = new CubeUpdate(currentInstanceCopy);
update.setCuboids(distCube.getCuboids());
List toRemoveSegs = Lists.newArrayList();
4. 研测验证：
Path statisticsFile = new Path(statisticsDir, BatchConstants.CFG_STATISTICS_CUBOID_ESTIMATION_FILENAME);
FileSystem fs = HadoopUtil.getWorkingFileSystem();
if (fs.exists(statisticsFile)) {
try (FSDataInputStream is = fs.open(statisticsFile)) { // 关闭流
ResourceStore.getStore(config).putBigResource(resKey, is, System.currentTimeMillis());
}
}
修改代码后，在研测环境进行多轮cube构建测试，CLOSE_WAIT 均无增加，验证解决。

Branch to commit

• Branch kylin3 for v2.x to v3.x
• Branch kylin4 for v4.x
• Branch kylin5 for v5.x

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