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hadoop-common-project/hadoop-common/src/site/markdown/release/0.18.3/RELEASENOTES.0.18.3.md

2.0.5-alpha-rc23.9 KB
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Apache Hadoop 0.18.3 Release Notes

These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.


  • HADOOP-4150 | Blocker | Include librecordio as part of the release

Included librecordio in release for use by xerces-c (ant -Dlibrecordio=true -Dxercescroot=<path to the xerces-c root>)


  • HADOOP-4061 | Major | Large number of decommission freezes the Namenode

Added a new conf property dfs.namenode.decommission.nodes.per.interval so that NameNode checks decommission status of x nodes for every y seconds, where x is the value of dfs.namenode.decommission.nodes.per.interval and y is the value of dfs.namenode.decommission.interval.


  • HADOOP-4659 | Blocker | Root cause of connection failure is being lost to code that uses it for delaying startup

WARNING: No release note provided for this change.


  • HADOOP-4542 | Minor | Fault in TestDistributedUpgrade

TestDistributedUpgrade used succeed for wrong reasons.


fix memory leak of user/group information in fuse-dfs


  • HADOOP-4679 | Major | Datanode prints tons of log messages: Waiting for threadgroup to exit, active theads is XX
  1. Only datanode's offerService thread shutdown the datanode to avoid deadlock;
  2. Datanode checks disk in case of failure on creating a block file.

  • HADOOP-4620 | Major | Streaming mapper never completes if the mapper does not write to stdout

This patch HADOOP-4620.patch (1) solves the hanging problem on map side with empty input and nonempty output — this map task generates output properly to intermediate files similar to other map tasks. (2) solves the problem of hanging reducer with empty input to reduce task and nonempty output — this reduce task doesn't generate output if input to reduce task is empty.


  • HADOOP-4797 | Blocker | RPC Server can leave a lot of direct buffers

Improve how RPC server reads and writes large buffers. Avoids soft-leak of direct buffers and excess copies in NIO layer.


  • HADOOP-4971 | Blocker | Block report times from datanodes could converge to same time.

A long (unexpected) delay at datanodes could make subsequent block reports from many datanode at the same time.


  • HADOOP-4997 | Blocker | workaround for tmp file handling on DataNodes in 0.18 (HADOOP-4663)

Revert tmp files handling on DataNodes back to 0.17. sync() introduced in 0.18 has less gaurantees.


Fix couple of JavaDoc warnings.