[ https://issues.apache.org/jira/browse/HADOOP-14872?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
John Zhuge updated HADOOP-14872: -------------------------------- Description: Discovered in IMPALA-5909. Opening an encrypted HDFS file returns a chain of wrapped input streams: {noformat} HdfsDataInputStream CryptoInputStream DFSInputStream {noformat} If an application such as Impala or HBase calls HdfsDataInputStream#unbuffer, FSDataInputStream#unbuffer will be called: {code:java} try { ((CanUnbuffer)in).unbuffer(); } catch (ClassCastException e) { throw new UnsupportedOperationException("this stream does not " + "support unbuffering."); } {code} If the {{in}} class does not implement CanUnbuffer, UOE will be thrown. If the application is not careful, tons of UOEs show in logs. In comparison, opening an non-encrypted HDFS file returns this chain: {noformat} HdfsDataInputStream DFSInputStream {noformat} DFSInputStream implements CanUnbuffer. It is good for CryptoInputStream to implement CanUnbuffer for 2 reasons: * Release buffer, cache, or any other resource when instructed * Avoid the UOE described above. Applications may not handle the UOE very well. was: Discovered in IMPALA-5909. Opening an encrypted HDFS file returns a chain of wrapped input streams: {noformat} HdfsDataInputStream CryptoInputStream DFSInputStream {noformat} If an application such as Impala or HBase calls HdfsDataInputStream#unbuffer, FSDataInputStream#unbuffer will be called: {code:java} try { ((CanUnbuffer)in).unbuffer(); } catch (ClassCastException e) { throw new UnsupportedOperationException("this stream does not " + "support unbuffering."); } {code} If the {{in}} class does not implement CanUnbuffer, UOE will be thrown. If the application is not careful, it can see tons of UOEs. In comparison opening an non-encrypted HDFS file return this chain: {noformat} HdfsDataInputStream DFSInputStream {noformat} DFSInputStream implements CanUnbuffer. It is good for CryptoInputStream to implement CanUnbuffer for 2 reasons: * Release buffer, cache, or any other resource when instructed * Avoid the UOE described above. Applications may not handle the UOE very well. > CryptoInputStream should implement CanUnbuffer > ---------------------------------------------- > > Key: HADOOP-14872 > URL: https://issues.apache.org/jira/browse/HADOOP-14872 > Project: Hadoop Common > Issue Type: Improvement > Components: fs > Affects Versions: 2.6.4 > Reporter: John Zhuge > Assignee: John Zhuge > Attachments: HADOOP-14872.001.patch > > > Discovered in IMPALA-5909. > Opening an encrypted HDFS file returns a chain of wrapped input streams: > {noformat} > HdfsDataInputStream > CryptoInputStream > DFSInputStream > {noformat} > If an application such as Impala or HBase calls HdfsDataInputStream#unbuffer, > FSDataInputStream#unbuffer will be called: > {code:java} > try { > ((CanUnbuffer)in).unbuffer(); > } catch (ClassCastException e) { > throw new UnsupportedOperationException("this stream does not " + > "support unbuffering."); > } > {code} > If the {{in}} class does not implement CanUnbuffer, UOE will be thrown. If > the application is not careful, tons of UOEs show in logs. > In comparison, opening an non-encrypted HDFS file returns this chain: > {noformat} > HdfsDataInputStream > DFSInputStream > {noformat} > DFSInputStream implements CanUnbuffer. > It is good for CryptoInputStream to implement CanUnbuffer for 2 reasons: > * Release buffer, cache, or any other resource when instructed > * Avoid the UOE described above. Applications may not handle the UOE very > well. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org