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  1. Hadoop Common
  2. HADOOP-14807

should prevent the possibility of NPE about ReconfigurableBase.java

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    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: 3.0.0-alpha3
    • Fix Version/s: 3.3.0
    • Component/s: None
    • Labels:
      None
    • Target Version/s:

      Description

      1.NameNode.java may throw a ReconfigurationException which getCause() is null

      NameNode.java
        
        protected String reconfigurePropertyImpl(String property, String newVal)
            throws ReconfigurationException {
          final DatanodeManager datanodeManager = namesystem.getBlockManager()
              .getDatanodeManager();
      
          if (property.equals(DFS_HEARTBEAT_INTERVAL_KEY)) {
            return reconfHeartbeatInterval(datanodeManager, property, newVal);
          } else if (property.equals(DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY)) {
            return reconfHeartbeatRecheckInterval(datanodeManager, property, newVal);
          } else if (property.equals(FS_PROTECTED_DIRECTORIES)) {
            return reconfProtectedDirectories(newVal);
          } else if (property.equals(HADOOP_CALLER_CONTEXT_ENABLED_KEY)) {
            return reconfCallerContextEnabled(newVal);
          } else if (property.equals(ipcClientRPCBackoffEnable)) {
            return reconfigureIPCBackoffEnabled(newVal);
          } 
         //=======================================================
         //here may throw a ReconfigurationException which getCause() is null
         //=======================================================
         else {
            throw new ReconfigurationException(property, newVal, getConf().get(
                property));
          }
        }
      

      2. ReconfigurationThread.java will call ReconfigurationException.getCause().getMessage() which will cause NPE.

      ReconfigurationThread.java
        
      private static class ReconfigurationThread extends Thread {
          private ReconfigurableBase parent;
      
          ReconfigurationThread(ReconfigurableBase base) {
            this.parent = base;
          }
      
          // See {@link ReconfigurationServlet#applyChanges}
          public void run() {
            LOG.info("Starting reconfiguration task.");
            final Configuration oldConf = parent.getConf();
            final Configuration newConf = parent.getNewConf();
            final Collection<PropertyChange> changes =
                parent.getChangedProperties(newConf, oldConf);
            Map<PropertyChange, Optional<String>> results = Maps.newHashMap();
            ConfigRedactor oldRedactor = new ConfigRedactor(oldConf);
            ConfigRedactor newRedactor = new ConfigRedactor(newConf);
            for (PropertyChange change : changes) {
              String errorMessage = null;
              String oldValRedacted = oldRedactor.redact(change.prop, change.oldVal);
              String newValRedacted = newRedactor.redact(change.prop, change.newVal);
              if (!parent.isPropertyReconfigurable(change.prop)) {
                LOG.info(String.format(
                    "Property %s is not configurable: old value: %s, new value: %s",
                    change.prop,
                    oldValRedacted,
                    newValRedacted));
                continue;
              }
              LOG.info("Change property: " + change.prop + " from \""
                  + ((change.oldVal == null) ? "<default>" : oldValRedacted)
                  + "\" to \""
                  + ((change.newVal == null) ? "<default>" : newValRedacted)
                  + "\".");
              try {
                String effectiveValue =
                    parent.reconfigurePropertyImpl(change.prop, change.newVal);
                if (change.newVal != null) {
                  oldConf.set(change.prop, effectiveValue);
                } else {
                  oldConf.unset(change.prop);
                }
              } catch (ReconfigurationException e) {
                //===============================================
                // here may occurs NPE,  because  e.getCause() may be null.
                //===============================================
                errorMessage = e.getCause().getMessage();
              }
              results.put(change, Optional.fromNullable(errorMessage));
            }
      
            synchronized (parent.reconfigLock) {
              parent.endTime = Time.now();
              parent.status = Collections.unmodifiableMap(results);
              parent.reconfigThread = null;
            }
          }
        }
      

        Attachments

        1. HADOOP-14807.001.patch
          1 kB
          hu xiaodong

          Activity

            People

            • Assignee:
              xiaodong.hu hu xiaodong
              Reporter:
              xiaodong.hu hu xiaodong
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              Dates

              • Created:
                Updated:
                Resolved: