Joe Pallas created HDFS-7680:
--------------------------------

             Summary: Support dataset-specific choice of short circuit 
implementation
                 Key: HDFS-7680
                 URL: https://issues.apache.org/jira/browse/HDFS-7680
             Project: Hadoop HDFS
          Issue Type: Sub-task
          Components: datanode, dfsclient, hdfs-client
    Affects Versions: 3.0.0
            Reporter: Joe Pallas
            Assignee: Joe Pallas


As described in HDFS-5194, the current support for short circuit reading is 
tightly coupled to the default Dataset implementation.  Since alternative 
implementations of the FsDatasetSpi may use a different short circuit pathway, 
there needs to be a way for the client to acquire the right kind of BlockReader.

Reviewing some considerations:
Today, there is only one dataset per datanode (with multiple volumes).  Is that 
likely to change?
Can there be multiple datanodes local to a client?
Is it okay to assume that the client and datanode share configuration?  More 
broadly, how should the client discover the appropriate short-circuit 
implementation?




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to