Apache ZooKeeper goes native for Windows C client

The new 3.4.0 release of Apache ZooKeeper, the Hadoop configuration management software, adds a native Windows version of its C client, extends monitoring support, and adds a web-based administrative interface. Over 150 issues, including new features and bug fixes, have been addressed in 3.4.0. The last major update to ZooKeeper, version 3.3.0, was 20 months ago in March 2010.

The native C client will allow developers to bind the ZooKeeper client to more languages and applications than is possible with the current Java client. On Unix, the C client has allowed ZooKeeper to work with C#, Node.js, Python, Erlang, Ruby and Go as well as Scala and Java. The Kerberos authentication support was initially developed to enable security in HBase; in 3.4.0 the ability to authenticate clients has been added. Developers will find multi-update, which allows multiple changes to be batched into an atomic operation, has also been added to the client interface.

Operators of ZooKeeper systems will be able to use new monitoring support with the additional tools and recipes that have been added to the contrib collection, including instructions on how to monitor the system using Nagios or Ganglia. A web-based administration interface and automatic cleaning of snapshots and logs have also been added, alongside the generation of deployment logging and statistics. ZooKeeper is now also able to generate RPM and DEB packaged versions of itself.

ZooKeeper 3.4.0 is not ready for production use, however, clients and servers from both versions can interoperate for what Cloudera calls a seamless upgrade path. The current stable version is ZooKeeper 3.3.3; 3.4.0 is a beta released specifically for testing. A later 3.4.x version will be declared production ready once that testing is complete.

Further details of the changes are available in the release notes; the various versions of ZooKeeper are available to download from Apache mirrors.

(djwm)