Fixes#2682
IndexingService helpers are added according to the settings in runtime.properties.
Rather than having all the config.isXXX checks there, it makes sense to have a pluggable
approach for allowing the dynamic configuration to bring in implementations for helpers
without having to have hard-coded sets of available helpers. Plus, it will also make it possible for extensions to plug helpers in.
With https://github.com/druid-io/druid-api/pull/76, we could conditionally bind a helper to Coordinator's runlist.
The condition is driven by the value set in the runtime.properties.
Usage example:
ConditionalMultibind.create(props, binder, Animal.class)
.conditionBinder("animal.type", Predicates.equalTo("cat"), Cat.class)
.conditionBinder("animal.type", Predicates.equalTo("dog"), Dog.class);
At binding time, this will check the value set for property "animal.type" in props. If the value is "cat", it will
add a binding to Cat.class. If the value is "dog", it will add a binding to Dog.class.
At ingestion time, you will get the items that satisfy their corresponding predicates by calling
injector.getInstance(Key.get(new TypeLiteral<Set<Animal>>(){}))
I believe that the instanceof chain in Filters exists because in the past, Filter
and DimFilter were in different packages (DimFilter was in druid-client and Filter
was in druid-processing). And since druid-client didn't depend on druid-processing,
DimFilter couldn't have a toFilter method. But now it can.
This removes Filter.makeMatcher(ColumnSelectorFactory) and adds a
ValueMatcherFactory implementation to FilteredAggregatorFactory so it can
take advantage of existing makeMatcher(ValueMatcherFactory) implementations.
This patch also removes the Bound-based method from ValueMatcherFactory. Its
only user was the SpatialFilter, which could use the Predicate-based method.
Fixes#2604.
- Add central doc for multi-value dimensions, with some content from other docs.
- Link to multi-value dimension doc from topN and groupBy docs.
- Fixes a broken link from dimensionspecs.md, which was presciently already
linking to this nonexistent doc.
- Resolve inconsistent naming in docs & code (sometimes "multi-valued", sometimes
"multi-value") in favor of "multi-value".