[HADOOP-12689] S3 filesystem operations stopped working correctly

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.0
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: tools
• Labels: S3
• Target Version/s: 2.8.0
• Assignee: Matthew Paduano
• Reporter: Matthew Paduano
• Created: 04/Jan/16 23:30
• Updated: 30/Aug/16 01:20
• Resolved: 06/Jan/16 07:44

Description

HADOOP-10542 was resolved by replacing "return null;" with throwing IOException. This causes several S3 filesystem operations to fail (possibly more code is expecting that null return value; these are just the calls I noticed):

S3FileSystem.getFileStatus() (which no longer raises FileNotFoundException but instead IOException)
FileSystem.exists() (which no longer returns false but instead raises IOException)
S3FileSystem.create() (which no longer succeeds but instead raises IOException)

Run command:

hadoop distcp hdfs://localhost:9000/test s3://xxx:[e-mail]/

Resulting stack trace:

2015-12-11 10:04:34,030 FATAL [IPC Server handler 6 on 44861] org.apache.hadoop.mapred.TaskAttemptListenerImpl: Task: attempt_1449826461866_0005_m_000006_0 - exited : java.io.IOException: /test doesn't exist
at org.apache.hadoop.fs.s3.Jets3tFileSystemStore.get(Jets3tFileSystemStore.java:170)
at org.apache.hadoop.fs.s3.Jets3tFileSystemStore.retrieveINode(Jets3tFileSystemStore.java:221)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy17.retrieveINode(Unknown Source)
at org.apache.hadoop.fs.s3.S3FileSystem.getFileStatus(S3FileSystem.java:340)
at org.apache.hadoop.tools.mapred.CopyMapper.map(CopyMapper.java:230)
at org.apache.hadoop.tools.mapred.CopyMapper.map(CopyMapper.java:50)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:146)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:787)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:164)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)

changing the "raise IOE..." to "return null" fixes all of the above code sites and allows distcp to succeed.

Issue Links

• is broken by: HADOOP-10542 Potential null pointer dereference in Jets3tFileSystemStore#retrieveBlock()
• relates to: HADOOP-12696 Add Tests for S3FileSystem Contract