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  1. Hadoop HDFS
  2. HDFS-6695

Investigate using Java 7's nonblocking file I/O in BlockReaderLocal to implement read timeouts

    Details

    • Type: Improvement
    • Status: Open
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None
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      Description

      In BlockReaderLocal, the "read" system call could block for a long time if the disk drive is having problems, or there is a huge amount of I/O contention. This might cause poor latency performance.

      In the remote block readers, we have implemented a read timeout, but we don't have one for the local block reader, since FileChannel#read doesn't support this.

      Once we move to JDK 7, we should investigate the java.nio.file nonblocking file I/O package to see if it could be used to implement read timeouts.

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              • Assignee:
                Unassigned
                Reporter:
                cmccabe Colin P. McCabe
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                • Created:
                  Updated: