* Cleaned up MapperService#searchFilter(...) and moved it DefaultSearchContext, since it that class was the only user. As part of the cleanup percolate query documents are no longer excluded from the search response.
* Removed resolveClosestNestedObjectMapper(...) method as it was no longer used.
* Removed DocumentTypeListener infrastructure. Before it was used by the percolator and parent/child, but these features no longer use it.
Closes#15924
* Remove remaining 1.x bwc logic.
* Stop storing stored fields and indexed terms. The _parent field's only purpose is to support joins between parent and child type and only storing doc values is sufficient.
* In the mapping the parent field mapper is now known under '{parent}#{child}' key, because this is the field the parent/child join uses too.
* Added new sub fetch phase to lookup that _parent field from doc values field if that is required (before this was fetched from stored _parent field)
* Removed the ability to query directly on `_parent` in the query dsl. Instead the `{parent}#{child}` field should be used. Under the hood a doc values query is used instead of a term query, because only doc values fields are stored now.
* Added a new `parent_id` query to easily query child documents with a specific parent id without having to know what join field to use
* Also in aggregations `_parent` field can't be used any more and `{parent}#{child}` field name should be used instead to aggregate directly on the _parent join field.
This commit modifies the load_average in the node stats API response
to be an object containing the one-minute, five-minute and
fifteen-minute load averages as fields (if those values are
available). Additionally, this commit modifies the cat nodes API
response to format the one-minute, five-minute and fifteen-minute load
averages as null if any of the respective values are not available.
The indexing buffer on a node (default: 10% of the JVM heap) is now a "shared pool" across all shards on that node. This way, shards doing intense indexing can use much more than other shards doing only light indexing, and only once the sum of all indexing buffers across all shards exceeds the node's indexing buffer will we ask shards to move recently indexed documents to segments on disk.
Warmers are now barely useful and will be removed in 3.0. Note that this only
removes the warmer API and query-based warmers. We still have warmers internally
for eg. global ordinals.
Close#15607
* Added percolator field mapper that extracts the query terms and indexes these terms with the percolator query.
* At percolate time these extracted terms are used to query percolator queries that are like to be evaluated. This can significantly cut down the time it takes to percolate. Whereas before all percolator queries were evaluated if they matches with the document being percolated.
* Changes made to percolator queries are no longer immediately visible, a refresh needs to happen before the changes are visible.
* By default the percolate api only returns upto 10 matches instead of returning all matching percolator queries.
* Made percolate more modular, so that it is easier to add unit tests.
* Added unit tests for the percolator.
Closes#12664Closes#13646
Adds task manager class and enables all activities to register with the task manager. Currently, the immutable Transport*Activity class represents activity itself shared across all requests. This PR adds and an additional structure Task that keeps track of currently running requests and can be used to communicate with these requests using TransportTaskAction.
Related to #15117