The Hortonworks Blog

Posts categorized by : ZooKeeper

Hortonworks would like to congratulate Leslie Lamport on winning the 2013 Turing Award given by the Association of Computing Machinery. This award is essentially the equivalent of the Nobel Prize for computer science.  Among Lamport’s many and varied contributions to the field computer science are: TLA (Temporal Logic for Actions)LaTeX and PAXOS.

The latter of these, the PAXOS three phase consensus protocol, inspires the Zookeeper coordination service, and powers HBase and highly available HDFS.…

As part of a modern data architecture, Hadoop needs to be a good citizen and trusted as part of the heart of the business. This means it must provide for all the platform services and features that are expected of an enterprise data platform.

The Hadoop Distributed File System is the rock at the core of HDP and provides reliable, scalable access to data for all analytical processing needs. With HDP 2.0, built into the platform itself, HDFS now has automated failover with a hot standby, with full stack resiliency.…

We’re continuing our series of quick interviews with Apache Hadoop project committers at Hortonworks.

This week Mahadev Konar discusses Apache ZooKeeper, the open source Apache project that is used to coordinate various processes on a Hadoop cluster (such as electing a leader between two processes).

Mahadev was on the team at Yahoo! in 2006 that started developing what became Apache Hadoop. He has been involved with Apache ZooKeeper since 2008, when the project was open sourced.…

Apache ZooKeeper™ release 3.4.5 is now available. This is a bug fix release including 3 bug fixes. Following is a summary of the critical issues fixed in the release.

ZOOKEEPER-1550: ZooKeeperSaslClient does not finish anonymous login on OpenJDK

ZOOKEEPER-1376: zkServer.sh does not correctly check for $SERVER_JVMFLAGS

ZOOKEEPER-1560: Zookeeper client hangs on creation of large nodes.

Stability of 3.4.5

Note that Apache ZooKeeper™ 3.4.5 is marked as the current stable release.…

Apache ZooKeeper release 3.4.4 is now available. This is a bug fix release including 50 bug fixes. Following is a summary of the critical issues fixed in the release.

ZOOKEEPER-1419 Leader Election never settles for a 5 node cluster

ZOOKEEPER-1489 Data loss after truncate on transaction log

ZOOKEEPER-1412 java client watches inconsistently triggered on reconnect

ZOOKEEPER-1344 ZooKeeper client multi-update command is not considering the Chroot request

ZOOKEEPER-1496 Ephemeral node not getting cleared even after client has exited

ZOOKEEPER-1437 Client uses session before SASL authentication complete

Stability of 3.4.4

As you might have noticed we have been marking all the previous 3.4.* releases as Alpha and beta.…

For those of you new to Apache ZooKeeper, it is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. To learn more about ZooKeeper, please visit the Apache ZooKeeper homepage.

As part of stabilizing Apache ZooKeeper 3.4 branch, ZooKeeper 3.4.3 has just been released. It is a bug fix release on the 3.4 branch and fixes 17 issues out of which 1 is very critical and can cause data inconsistency (ZOOKEEPER-1367).…