I'm very pleased to announce that the Apache Hadoop community has released hadoop-2.0.3-alpha!
This delivers significant major enhancements and stability over previous releases in hadoop-2.x series:
# QJM for HDFS HA for NameNode
# Multi-resource scheduling (CPU and memory) for YARN
# YARN ResourceManager Restart
# Significant stability at scale for YARN (over 30,000 nodes and 14 million applications so far, at time of release - see here)
This release, like previous releases in hadoop-2.x series, is still considered *alpha* primarily since some of APIs aren't fully-baked, has had some churn and we expect some more in future hadoop-2.x releases. Furthermore, please note that there are some API changes from previous hadoop-2.0.2-alpha release and applications will need to recompile against hadoop-2.0.3-alpha. Please see the Hadoop 2.0.3-alpha Release Notes for details.
Furthermore, we are converging fast on ironing out API issues (both HDFS & YARN) and, currently, plan to cut a hadoop-2.0.4-beta release in the next couple of months after this effort. We believe that hadoop-2.0.4-beta will be a major step to then release a fully stable, supported hadoop-2 release, exciting times! Stay tuned!
(your humble, sometimes prone to grumble, release manager... *smile*)