AssignmentManager is a module in the Apache HBase Master that manages regions to RegionServers assignment. (See HBase architecture for more information.) It ensures that all regions are assigned and each region is assigned to just one RegionServer.
Although the AssignmentManager generally does a good job, the existing implementation does not handle assignments as well as it could. For example, if a region was assigned to two or more RegionServers,
Apache ZooKeeper release 3.4.5 is now available. This is a bug fix release covering 3 issues, one of which was considered critical. These issues were:
- ZOOKEEPER-1550 ZooKeeperSaslClient does not finish anonymous login on OpenJDK
- ZOOKEEPER-1560 Zookeeper client hangs on creation of large nodes
- ZOOKEEPER-1376 zkServer.sh does not correctly check for $SERVER_JVMFLAGS
Stability, Compatibility and Testing
3.4.5 is a stable release that’s fully backward compatible with 3.4.4.
Update time! As a reminder, Cloudera releases major versions of CDH, our 100% open source distribution of Apache Hadoop and related projects, annually and then updates to CDH every three months. Updates primarily comprise bug fixes but we will also add enhancements. We only include fixes or enhancements in updates that maintain compatibility, improve system stability and still allow customers and users to skip updates as they see fit.
We’re pleased to announce the availability of CDH4.1.
Apache ZooKeeper release 3.4.4 is now available. This is a bug fix release covering 50 issues, four of which were considered blockers. Some of the more serious issues include:
- ZOOKEEPER-1419 Leader election never settles for a 5-node cluster
- ZOOKEEPER-1489 Data loss after truncate on transaction log
- ZOOKEEPER-1466 QuorumCnxManager.shutdown missing synchronization
- ZOOKEEPER-1412 java client watches inconsistently triggered on reconnect
- ZOOKEEPER-1427 Writing to local files is done non-atomically
- ZOOKEEPER-1465 Cluster availability following new leader election takes a long time with large datasets –
Strata Conference + Hadoop World (Oct. 23-25 in New York City) is a bonanza for Hadoop and big data enthusiasts – but not only because of the technical sessions and tutorials. It’s also an important gathering place for the developer community, most of whom are eager to share info from their experiences in the “trenches”.
Just to make that process easier, Cloudera is teaming up with local meetups during that week to organize a series of meetings on a variety of topics.