“Apache Hadoop” 2.9.1 Release Notes

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

  • HADOOP-12756 | Major | Incorporate Aliyun OSS file system implementation

Aliyun OSS is widely used among China’s cloud users and this work implemented a new Hadoop compatible filesystem AliyunOSSFileSystem with oss scheme, similar to the s3a and azure support.

  • HADOOP-14964 | Major | AliyunOSS: backport Aliyun OSS module to branch-2

Aliyun OSS is widely used among China’s cloud users and this work implemented a new Hadoop compatible filesystem AliyunOSSFileSystem with oss:// scheme, similar to the s3a and azure support.

  • HDFS-12883 | Major | RBF: Document Router and State Store metrics

This JIRA makes following change: Change Router metrics context from ‘router’ to ‘dfs’.

  • HDFS-12895 | Major | RBF: Add ACL support for mount table

Mount tables support ACL, The users won't be able to modify their own entries (we are assuming these old (no-permissions before) mount table with owner:superuser, group:supergroup, permission:755 as the default permissions). The fix way is login as superuser to modify these mount table entries.

  • YARN-7190 | Major | Ensure only NM classpath in 2.x gets TSv2 related hbase jars, not the user classpath

Ensure only NM classpath in 2.x gets TSv2 related hbase jars, not the user classpath.

  • HADOOP-15156 | Major | backport HADOOP-15086 rename fix to branch-2

[WASB] Fix Azure implementation of Filesystem.rename to ensure that at most one operation succeeds when there are multiple, concurrent rename operations targeting the same destination file.

  • HADOOP-15027 | Major | AliyunOSS: Support multi-thread pre-read to improve sequential read from Hadoop to Aliyun OSS performance

Support multi-thread pre-read in AliyunOSSInputStream to improve the sequential read performance from Hadoop to Aliyun OSS.

  • HDFS-13083 | Major | RBF: Fix doc error setting up client

Fix the document error of setting up HFDS Router Federation

  • HDFS-13099 | Minor | RBF: Use the ZooKeeper as the default State Store

Change default State Store from local file to ZooKeeper. This will require additional zk address to be configured.