[jira] [Commented] (HADOOP-15515) adl.AdlFilesystem.close() doesn't release locks on open files

["Chris Douglas (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HADOOP-15515?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16502310#comment-16502310 ] 

Chris Douglas commented on HADOOP-15515:
----------------------------------------

Moving to common, as this doesn't affect HDFS. v002 seems to implement a pattern similar to [DFSClient|https://github.com/apache/hadoop/blob/trunk/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSClient.java#L626].

bq. As I can't see a way to force lease recovery in this situation
As long as this is only an optimization- and a client failing to release the lock won't wedge the system- this looks OK. I checked the [client docs|https://azure.github.io/azure-data-lake-store-java/javadoc/], and it looks like the ADL client doesn't have a {{close}} method, so presumably it's not tracking open streams and this is correct.

If there's no other feedback I'll commit this soon.

> adl.AdlFilesystem.close() doesn't release locks on open files
> -------------------------------------------------------------
>
>                 Key: HADOOP-15515
>                 URL: https://issues.apache.org/jira/browse/HADOOP-15515
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: fs/adl
>    Affects Versions: 2.7.3
>         Environment: HDInsight on MS Azure:
>  
> Hadoop 2.7.3.2.6.2.25-1
> Subversion git@github.com:hortonworks/hadoop.git -r 1ceeb58bb3bb5904df0cbb7983389bcaf2ffd0b6
> Compiled by jenkins on 2017-11-29T15:28Z
> Compiled with protoc 2.5.0
> From source with checksum 90b73c4c185645c1f47b61f942230
> This command was run using /usr/hdp/2.6.2.25-1/hadoop/hadoop-common-2.7.3.2.6.2.25-1.jar
>            Reporter: Jay Hankinson
>            Assignee: Vishwajeet Dusane
>            Priority: Major
>         Attachments: HDFS-13344-001.patch, HDFS-13344-002.patch
>
>
> If you write to a file on and Azure ADL filesystem and close the file system but not the file before the process exits, the next time you try open the file for append it fails with:
> Exception in thread "main" java.io.IOException: APPEND failed with error 0x83090a16 (Failed to perform the requested operation because the file is currently open in write mode by another user or process.). [a67c6b32-e78b-4852-9fac-142a3e2ba963][2018-03-22T20:54:08.3520940-07:00]
>  The following moves local file to HDFS if it doesn't exist or appends it's contents if it does:
>  
> {code:java}
> public void addFile(String source, String dest, Configuration conf) throws IOException {
> FileSystem fileSystem = FileSystem.get(conf);
> // Get the filename out of the file path
> String filename = source.substring(source.lastIndexOf('/') + 1,source.length());
> // Create the destination path including the filename.
> if (dest.charAt(dest.length() - 1) != '/')
> { dest = dest + "/" + filename; }
> else {
> dest = dest + filename;
> }
> // Check if the file already exists
> Path path = new Path(dest);
> FSDataOutputStream out;
> if (fileSystem.exists(path)) {
> System.out.println("File " + dest + " already exists appending");
> out = fileSystem.append(path);
> } else {
> out = fileSystem.create(path);
> }
> // Create a new file and write data to it.
> InputStream in = new BufferedInputStream(new FileInputStream(new File(
> source)));
> byte[] b = new byte[1024];
> int numBytes = 0;
> while ((numBytes = in.read(b)) > 0) {
> out.write(b, 0, numBytes);
> }
> // Close the file system not the file
> in.close();
> //out.close();
> fileSystem.close();
> }
> {code}
>  If "dest" is an adl:// location, invoking the function a second time (after the process has exited) it raises the error. If it's a regular hdfs:// file system, it doesn't as all the locks are released. The same exception is also raised if a subsequent append is done using: hdfs dfs  -appendToFile.
> As I can't see a way to force lease recovery in this situation, this seems like a bug. org.apache.hadoop.fs.adl.AdlFileSystem inherits close() from org.apache.hadoop.fs.FileSystem
> [https://hadoop.apache.org/docs/r3.0.0/api/org/apache/hadoop/fs/adl/AdlFileSystem.html]
> Which states:
> Close this FileSystem instance. Will release any held locks. This does not seem to be the case



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