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)