Release Druid 0.8.1 - Stable · apache/druid

Updating from 0.8.0

There should be no update concerns and standard updating procedures can be followed for rolling updates

#1259 Experimental Query Time Lookups (QTL) -– Ability to do limited joins at query time.
Simple example use case is Country Code to Country Name.
#1374 Experimental Hadoop batch re-indexing and Delta ingestion.
Re-Indexing allows you to ingest existing druid segments using a new schema with certain columns removed, changed granularity etc. "Delta" Ingestion allows appending data to existing interval in a datasource. See the new dataSource inputSpec and multi inputSpec for more information.

#1465 Read Hadoop configuration file from HDFS
#1472 Support using combiner for Hadoop ingestion
#1506 Better support for null input rows during ingestion
#1518 More support added for Azure deep store
#1550 Add configuration option to print all HTTP requests to log
#1563 #1602 Improved merging performance on Broker
#1567 #1568 Improved error logging for segment activities
#1596 Improved coordinator console, now a separate maven dependency instead of giant code dump
#1601 Reduced lock contention during segment scan
#1603 Improved performance of Lexicographic TopNs
#1643 helpful cause explaining why SegmentDescriptorInfo did not exist

Improved test coverage for indexing service, ingestion, and coordinator endpoints

#1406 Fix groupBy breaking when exceeding max intermediate rows
#1441 Fix flush errors being suppressed when closing output streams
#1469 Fix inconsistent property names for druid.metadata.* properties
#1484 JobHelper.ensurePaths will set properties from config properly
#1499 Fix groupBy caching with renamed aggregators
#1503 Fix leaking indexing service status nodes in ZK
#1534 Fix caching for approximate histograms
#1616 Fix dependency error in local index task
#1627 Fix realtime tasks getting stuck on shutdown even after status being shown as SUCCESS
#1634 Allow IrcFirehoseFactory to shutdown cleanly
#1640 Package extensions in release tarball + script to run druid servers
#1653 Fix success flag emitted in router query metrics
#1659 on kill segment, don't leave version, interval and dataSource dir behind on HDFS
#1681 Fix overlapping segments not working for ingest segment firehose

The full list of changes can be found here

Special thanks to everyone that contributed (code, docs, etc.) to this release!