[HDFS-8136] Client gets and uses EC schema when reads and writes a stripping file

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: HDFS-7285
• Fix Version/s: HDFS-7285
• Hadoop Flags: Reviewed
• Assignee: Kai Sasaki
• Reporter: Kai Zheng
• Created: 13/Apr/15 22:47
• Updated: 30/Sep/15 19:38
• Resolved: 23/Apr/15 08:23

Description

Discussed with umamaheswararao and vinayrpet, in client when reading and writing a stripping file, it can invoke a separate call to NameNode to request the EC schema associated with the EC zone where the file is in. Then the schema can be used to guide the reading and writing. Currently it uses hard-coded values.

Optionally, as an optimization consideration, client may cache schema info per file or per zone or per schema name. We could add schema name in HdfsFileStatus for that.

Issue Links

• Is contained by: HDFS-8062 Remove hard-coded values in favor of EC schema