Adding stat for query with filter

[martin-gaievski]

Signed-off-by: Martin Gaievski [email protected]

Description

Adding counter stat "knn_query_with_filter_requests" for queries with filter field. Example of response with new stat

    "nodes": {
        "gIsW_7cBQwqSeZ2sr5knEw": {
            "graph_memory_usage_percentage": 0.0,
            "graph_query_requests": 0,
            "graph_memory_usage": 0,
            "cache_capacity_reached": false,
            "load_success_count": 0,
            "training_memory_usage": 0,
            "indices_in_cache": {},
            "script_query_errors": 0,
            "hit_count": 0,
            "knn_query_requests": 2,
            "total_load_time": 0,
            "miss_count": 0,
            "knn_query_with_filter_requests": 1,
            "training_memory_usage_percentage": 0.0,
            "lucene_initialized": true,
            "graph_index_requests": 0,
            "faiss_initialized": false,
            "load_exception_count": 0,
            "training_errors": 0,
            "eviction_count": 0,
            "nmslib_initialized": false,
            "script_compilations": 0,
            "script_query_requests": 0,
            "graph_query_errors": 0,
            "indexing_from_model_degraded": false,
            "graph_index_errors": 0,
            "training_requests": 0,
            "script_compilation_errors": 0
        }
    }

Issues Resolved

#376

Check List

• New functionality includes testing.
  • All tests pass
• Commits are signed as per the DCO using --signoff

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[codecov-commenter]

Codecov Report

Merging #587 (6f7821f) into feature/efficient-filtering (44f10de) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@                        Coverage Diff                        @@
##             feature/efficient-filtering     #587      +/-   ##
=================================================================
+ Coverage                          84.49%   84.51%   +0.02%     
  Complexity                          1054     1054              
=================================================================
  Files                                149      149              
  Lines                               4295     4301       +6     
  Branches                             382      382              
=================================================================
+ Hits                                3629     3635       +6     
  Misses                               489      489              
  Partials                             177      177              

Impacted Files	Coverage Δ
...rg/opensearch/knn/index/query/KNNQueryBuilder.java	84.21% <100.00%> (+0.10%)	⬆️
...va/org/opensearch/knn/plugin/stats/KNNCounter.java	100.00% <100.00%> (ø)
...rg/opensearch/knn/plugin/stats/KNNStatsConfig.java	98.07% <100.00%> (+0.11%)	⬆️
...ava/org/opensearch/knn/plugin/stats/StatNames.java	89.74% <100.00%> (+0.26%)	⬆️

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[jmazanec15]

LGTM. Please make sure docs get updated as well.