This PR accumulates many refactorings and small improvements that I did while preparing the next change set of https://github.com/druid-io/druid/projects/2. I finally decided to make them a separate PR to minimize the volume of the main PR.
Some of the changes:
- Renamed confusing "Generic Column" term to "Numeric Column" (what it actually implies) in many class names.
- Generified `ComplexMetricExtractor`
* Rename io.druid to org.apache.druid.
* Fix META-INF files and remove some benchmark results.
* MonitorsConfig update for metrics package migration.
* Reorder some dimensions in inner queries for some reason.
* Fix protobuf tests.
* Make using implicit system charset an error
* Use StringUtils.toUtf8() and fromUtf8() instead of String.getBytes() and new String()
* Use English locale in StringUtils.safeFormat()
* Restore comment
* Initial commit
* Apply another config: clustername
* Rename variable
* Fix bug
* Add retry logic
* Edit retry logic
* Upgrade kafka-clients version to the most recent release
* Make callback single object
* Write documentation
* Rewrite error message and emit logic
* Handling AlertEvent
* Override toString()
* make clusterName more optional
* bump up druid version
* add producer.config option which make user can apply another optional config value of kafka producer
* remove potential blocking in emit()
* using MemoryBoundLinkedBlockingQueue
* Fixing coding convention
* Remove logging every exception and just increment counting
* refactoring
* trivial modification
* logging when callback has exception
* Replace kafka-clients 0.10.1.1 with 0.10.2.0
* Resolve the problem related of classloader
* adopt try statement
* code reformatting
* make variables final
* rewrite toString
David Lim
QiuMM
Roman Leventov
Gian Merlino
Jonathan Wei
Yuewen Wang
Dongkyu Hwangbo