[HDFS-8378] Erasure Coding: Few improvements for the erasure coding worker

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: HDFS-7285
• Target Version/s: HDFS-7285
• Hadoop Flags: Reviewed
• Assignee: Rakesh Radhakrishnan
• Reporter: Rakesh Radhakrishnan
• Created: 12/May/15 07:40
• Updated: 30/Sep/15 19:37
• Resolved: 19/May/15 07:00

Description

1. Following log is confusing, make it tidy. Its missing break; statement and causing this unwanted logs.

   2015-05-10 15:06:45,878 INFO  datanode.DataNode (BPOfferService.java:processCommandFromActive(728)) - DatanodeCommand action: DNA_ERASURE_CODING_RECOVERY
   2015-05-10 15:06:45,879 WARN  datanode.DataNode (BPOfferService.java:processCommandFromActive(732)) - Unknown DatanodeCommand action: 11
   

2. Add exception trace to the log, would improve debuggability

   } catch (Throwable e) {
      LOG.warn("Failed to recover striped block: " + blockGroup);
   }
   

3. Make member variables present in ErasureCodingWorker, ReconstructAndTransferBlock, StripedReader private final
4. Correct spelling of the variable STRIPED_READ_TRHEAD_POOL to STRIPED_READ_THREAD_POOL
5. Good to add debug logs to print the striped read pool size

   LOG.debug("Using striped reads; pool threads=" + num);
   

6. Add meaningful message to the precondition check:

   Preconditions.checkArgument(liveIndices.length == sources.length);
   

7. Remove unused import

   import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;