Apache Hadoop 2.5.0 Release Notes

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

Add getUGIFromSubject to leverage an external kerberos authentication

The offlineimageviewer no longer generates lsr-style outputs. The functionality has been superseded by a tool that takes the fsimage and exposes WebHDFS-like API for user queries.

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SaslRpcServer.SASL_PROPS is removed. Any use of this variable should be replaced with the following code: SaslPropertiesResolver saslPropsResolver = SaslPropertiesResolver.getInstance(conf); Map<String, String> sasl_props = saslPropsResolver.getDefaultProperties();

WARNING: No release note provided for this change.

Remove MRv1 settings from hadoop-metrics2.properties, add YARN settings instead.

HDFS-6273 introduces two new HDFS configuration keys: - dfs.namenode.http-bind-host - dfs.namenode.https-bind-host

The most common use case for these keys is to have the NameNode HTTP (or HTTPS) endpoints listen on all interfaces on multi-homed systems by setting the keys to i.e. INADDR_ANY.

For the systems background on this usage of INADDR_ANY please refer to ip(7) in the Linux Programmer’s Manual (web link: http://man7.org/linux/man-pages/man7/ip.7.html).

These keys complement the existing NameNode options: - dfs.namenode.rpc-bind-host - dfs.namenode.servicerpc-bind-host

s3 server-side encryption is now supported.

To enable this feature, specify the following in your client-side configuration:

name: fs.s3n.server-side-encryption-algorithm value: AES256

Set “dfs.namenode.legacy-oiv-image.dir” to an appropriate directory to make standby name node or secondary name node save its file system state in the old fsimage format during checkpointing. This image can be used for offline analysis using the OfflineImageViewer. Use the “hdfs oiv_legacy” command to process the old fsimage format.

Log slow i/o. Set log thresholds in dfsclient and datanode via the below new configs:

dfs.client.slow.io.warning.threshold.ms (Default 30 seconds) dfs.datanode.slow.io.warning.threshold.ms (Default 300ms)

WARNING: No release note provided for this change.

WARNING: No release note provided for this change.