[HADOOP-12724] Let BufferedFSInputStream implement CanUnbuffer

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Labels: stream
• Assignee: Unassigned
• Reporter: Ted Yu
• Created: 21/Jan/16 00:32
• Updated: 28/Sep/17 17:03

Description

When trying to determine reason for test failure over in HBASE-9393, I saw the following exception:

testSeekTo[4](org.apache.hadoop.hbase.io.hfile.TestSeekTo)  Time elapsed: 0.033 sec  <<< ERROR!
java.lang.UnsupportedOperationException: this stream does not support unbuffering.
	at org.apache.hadoop.fs.FSDataInputStream.unbuffer(FSDataInputStream.java:229)
	at org.apache.hadoop.fs.FSDataInputStream.unbuffer(FSDataInputStream.java:227)
	at org.apache.hadoop.hbase.io.hfile.HFile.pickReaderVersion(HFile.java:518)
	at org.apache.hadoop.hbase.io.hfile.HFile.createReader(HFile.java:562)
	at org.apache.hadoop.hbase.io.hfile.TestSeekTo.testSeekToInternals(TestSeekTo.java:307)
	at org.apache.hadoop.hbase.io.hfile.TestSeekTo.testSeekTo(TestSeekTo.java:298)

Here is the cause:

java.lang.ClassCastException: org.apache.hadoop.fs.BufferedFSInputStream cannot be cast to org.apache.hadoop.fs.CanUnbuffer

See the comments starting with https://issues.apache.org/jira/browse/HBASE-9393?focusedCommentId=15105939&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15105939 for background on the HBase patch.

This issue is to make BufferedFSInputStream implement CanUnbuffer.

This would benefit hbase unit tests.

Thanks to cmccabe for discussion.

Issue Links

• is related to: HBASE-9393 Region Server fails to properly close socket resulting in many CLOSE_WAIT to Data Nodes