* Adds kafka, URI, and JDBC namespace defintions
* Add ability to explicitly rename using a "namespace" which is a particular data collection that is loaded on all realtime, historic nodes, and brokers. If any of these nodes has the namespace extension, ALL nodes have the namespace extension.
* Add namespace caching and populating (can be on heap or off heap)
* Add NamespaceExtractionCacheManager for handling caches
* Added ExtractionNamespace for handling metadata on the extraction namespaces
* Added ExtractionNamespaceUpdate for handling metadata related to updates
* Add extension which caches renames from a kafka stream (requires kafka8)
* Added README.md for the namespace kafka extension
* Added docs
* Added namespace/size, namespace/count, namespace/deltaTasksStarted metrics
Add static config for namespaces via `druid.query.extraction.namespace`
* This is a rebase of https://github.com/b-slim/druid/tree/static_config_only
renamed all [Max/Min]*.java to [DoubleMax/DoubleMin]*.java and created [Max/Min]AggregatorFactory.java which can be removed when we dont need the min/max aggregator type backward compatibility
* Remove hard-coded azure path manipulation from the puller.
* Fix segment size not being zero after uploading it do Azure.
* Remove both index and desc files only on a success upload to Azure.
* Add Azure container name to load spec.
This patch would help future-proof azure deep-storage module and avoid
having to introduce ugly backwards-compatibility fixes when we want to
support multiple containers or moving data between containers.
* Requires https://github.com/druid-io/druid-api/pull/37
* Requires https://github.com/metamx/java-util/pull/22
* Moves the puller logic to use a more standard workflow going through java-util helpers instead of re-writing the handlers for each impl
* General workflow goes like this: 1) LoadSpec makes sure the correct Puller is called with the correct parameters. 2) The Puller sets up general information like how to make an InputStream, how to find a file name (for .gz files for example), and when to retry. 3) CompressionUtils does most of the heavy lifting when it can