[HADOOP-7090] Possible resource leaks in hadoop core code

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.21.0, 0.23.0
• Fix Version/s: 0.23.0
• Component/s: fs/s3, io
• Hadoop Flags: Reviewed
• Tags: resource leak
• Assignee: Uma Maheswara Rao G
• Reporter: Gokul
• Created: 06/Jan/11 06:19
• Updated: 15/Nov/11 00:50
• Resolved: 05/Jul/11 17:31

Description

It is always a good practice to close the IO streams in a finally block..

For example, look at the following piece of code in the Writer class of BloomMapFile

BloomMapFile .java

    public synchronized void close() throws IOException {
      super.close();
      DataOutputStream out = fs.create(new Path(dir, BLOOM_FILE_NAME), true);
      bloomFilter.write(out);
      out.flush();
      out.close();
    }

If an exception occurs during fs.create or on any other line, out.close() will not be executed..

The following can reduce the scope of resorce leaks..

BloomMapFile .java

    public synchronized void close() throws IOException {
      super.close();
      DataOutputStream out = null;
      try{
          out = fs.create(new Path(dir, BLOOM_FILE_NAME), true);
          bloomFilter.write(out);
          out.flush();
      }finally{
	 IOUtils.closeStream(out);
    }