This change adds support for the new ranking evaluation API to the High Level Rest Client.
This mostly means adding support for parsing the various response objects back from the
REST representation. It includes one change to the response syntax where previously we didn't
print the type of the metric details section but we now need it to pick the right parser to
parse this section back.
Closes#28198
Currenty the rest response of the ranking evaluation API wraps all inside an
enclosing `rank_eval` object. This is redundant since it is clear from the API
call and it doesn't provide any other useful information. This change removes
this.
Removing the unnecessary RankEvalTestHelper, making use of the common test infra
in ESTestCase, also hardening a few of the classes by making more fields final.
Problem: So far all rank eval requests are being executed in parallel. If there
are more than the search thread pool can handle, or if there are other search
requests executed in parallel rank eval can fail.
Solution: Make number of max_concurrent_searches configurable.
Name of configuration parameter is analogous to msearch. Default
max_concurrent_searches set to 10: Rank_eval isn't particularly time critical so
trying to avoid being more clever than probably needed here. Can set this value
through the API to a higher value anytime.
Fixes#21403
Problem: We introduced the ability to shorten the rank eval request by using a
template in #20231. When playing with the API it turned out that there might be
use cases where - e.g. due to various heuristics - folks might want to translate
the original user query into more than just one type of Elasticsearch query.
Solution: Give each template an id that can later be referenced in the
actual requests.
Closes#21257
Add checks to RankEvalSpec to safe guard against missing parameters.
Fail early in case no metric is supplied, no rated requests are supplied or the search source builder is missing but no template is supplied neither.
Add stricter checks around rank eval request parsing: Fail if in a rated request we see both, a verbatim request as well as request
template parameters.
Relates to #21260
Adds tests around serialisation/validation checks for rank evaluation request components
* Add null/ empty string checks to RatedDocument constructor
* Add mutation test to RatedDocument serialization tests.
* Reorganise rank-eval RatedDocument tests and add serialisation test.
* Add roundtrip serialisation testing for RatedRequests
* Adds serialisation testing and equals/hashcode testing for RatedRequest.
* Fixes a bug in previous equals implementation of RatedRequest along the way.
* Add roundtrip tests for Precision and ReciprocalRank
* Also fixes a bug with serialising ReciprocalRank.
* Add roundtrip testing for DiscountedCumulativeGain
* Add serialisation test for DocumentKey and fix test init
* Add check that relevant doc threshold is always positive for precision.
* Check that relevant threshold is always positive for precision and reciprocal
rank
Closes#21401
Move rank-eval template compilation down to TransportRankEvalAction
Closes#21777 and #21465
Search templates for rank_eval endpoint so far only worked when sent through
REST end point
However we also allow templates to be set through a Java API call to
"setTemplate" on that same spec. This doesn't go through template execution so
fails further down the line.
To make this work, moved template execution further down, probably to
TransportRankEvalAction.
* Add template IT test for Java API
* Move template compilation to TransportRankEvalAction
Currently we fail the whole ranking evaluation request when we receive an
exception for any of the search requests. We should collect those errors and
report them back to the user in the rest response. This change adds collecting
the errors and propagating them back via the RankEvalResponse.
Closes#19889
Our current default behaviour to ignore unrated documents when calculating the
precision seems a bit counter intuitive. Instead we should treat those documents
as "irrelevant" by default and provide an optional parameter to ignore those
documents if that is the behaviour the user wants.