[HDFS-8920] Erasure Coding: when recovering lost blocks, logs can be too verbose and hurt performance

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: HDFS-7285
• Hadoop Flags: Reviewed
• Assignee: Rui Li
• Reporter: Rui Li
• Created: 19/Aug/15 01:54
• Updated: 30/Sep/15 19:38
• Resolved: 22/Sep/15 06:17

Description

When we test reading data with datanodes killed, DFSInputStream::getBestNodeDNAddrPair becomes a hot spot method and effectively blocks the client JVM. This log seems too verbose:

    if (chosenNode == null) {
      DFSClient.LOG.warn("No live nodes contain block " + block.getBlock() +
          " after checking nodes = " + Arrays.toString(nodes) +
          ", ignoredNodes = " + ignoredNodes);
      return null;
    }