ESQL: Add MV_PSERIES_WEIGHTED_SUM for score calculations used by security solution

docs/changelog/109017.yaml

@@ -0,0 +1,6 @@
+pr: 109017
+summary: "ESQL: Add `MV_PSERIES_WEIGHTED_SUM` for score calculations used by security\
+  \ solution"
+area: ES|QL
+type: "feature"
+issues: [ ]

docs/reference/esql/functions/mv-functions.asciidoc

@@ -18,6 +18,7 @@
 * <<esql-mv_max>>
 * <<esql-mv_median>>
 * <<esql-mv_min>>
+* <<esql-mv_pseries_weighted_sum>>
 * <<esql-mv_sort>>
 * <<esql-mv_slice>>
 * <<esql-mv_sum>>
@@ -34,6 +35,7 @@ include::layout/mv_last.asciidoc[]
 include::layout/mv_max.asciidoc[]
 include::layout/mv_median.asciidoc[]
 include::layout/mv_min.asciidoc[]
+include::layout/mv_pseries_weighted_sum.asciidoc[]
 include::layout/mv_slice.asciidoc[]
 include::layout/mv_sort.asciidoc[]
 include::layout/mv_sum.asciidoc[]

x-pack/plugin/esql/qa/testFixtures/src/main/java/org/elasticsearch/xpack/esql/CsvTestsDataLoader.java

@@ -55,6 +55,7 @@ public class CsvTestsDataLoader {
     private static final TestsDataset HOSTS = new TestsDataset("hosts", "mapping-hosts.json", "hosts.csv");
     private static final TestsDataset APPS = new TestsDataset("apps", "mapping-apps.json", "apps.csv");
     private static final TestsDataset LANGUAGES = new TestsDataset("languages", "mapping-languages.json", "languages.csv");
+    private static final TestsDataset ALERTS = new TestsDataset("alerts", "mapping-alerts.json", "alerts.csv");
     private static final TestsDataset UL_LOGS = new TestsDataset("ul_logs", "mapping-ul_logs.json", "ul_logs.csv");
     private static final TestsDataset SAMPLE_DATA = new TestsDataset("sample_data", "mapping-sample_data.json", "sample_data.csv");
     private static final TestsDataset SAMPLE_DATA_STR = new TestsDataset(
@@ -106,6 +107,7 @@ public class CsvTestsDataLoader {
         Map.entry(LANGUAGES.indexName, LANGUAGES),
         Map.entry(UL_LOGS.indexName, UL_LOGS),
         Map.entry(SAMPLE_DATA.indexName, SAMPLE_DATA),
+        Map.entry(ALERTS.indexName, ALERTS),
         Map.entry(SAMPLE_DATA_STR.indexName, SAMPLE_DATA_STR),
         Map.entry(SAMPLE_DATA_TS_LONG.indexName, SAMPLE_DATA_TS_LONG),
         Map.entry(CLIENT_IPS.indexName, CLIENT_IPS),

x-pack/plugin/esql/qa/testFixtures/src/main/resources/alerts.csv

@@ -0,0 +1,11 @@
+host.name:keyword,kibana.alert.risk_score:double
+test-host-1,21.0
+test-host-2,17.0
+test-host-2,23.0
+test-host-1,45.0
+test-host-2,12.0
+test-host-2,16.0
+test-host-1,21.0
+test-host-1,70.0
+test-host-1,21.0
+test-host-2,5.0

x-pack/plugin/esql/qa/testFixtures/src/main/resources/mapping-alerts.json

@@ -0,0 +1,10 @@
+{
+  "properties": {
+    "host.name": {
+      "type": "keyword"
+    },
+    "kibana.alert.risk_score": {
+      "type": "double"
+    }
+  }
+}

x-pack/plugin/esql/qa/testFixtures/src/main/resources/meta.csv-spec

@@ -53,6 +53,7 @@ double e()
 "boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version mv_max(field:boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version)"
 "double|integer|long|unsigned_long mv_median(number:double|integer|long|unsigned_long)"
 "boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version mv_min(field:boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version)"
+"double mv_pseries_weighted_sum(number:double, p:double)"
 "boolean|cartesian_point|cartesian_shape|date|double|geo_point|geo_shape|integer|ip|keyword|long|text|version mv_slice(field:boolean|cartesian_point|cartesian_shape|date|double|geo_point|geo_shape|integer|ip|keyword|long|text|version, start:integer, ?end:integer)"
 "boolean|date|double|integer|ip|keyword|long|text|version mv_sort(field:boolean|date|double|integer|ip|keyword|long|text|version, ?order:keyword)"
 "double|integer|long|unsigned_long mv_sum(number:double|integer|long|unsigned_long)"
@@ -174,6 +175,7 @@ mv_last       |field                               |"boolean|cartesian_point|car
 mv_max        |field                               |"boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version"                                                          |Multivalue expression.
 mv_median     |number                              |"double|integer|long|unsigned_long"                                                                                               |Multivalue expression.
 mv_min        |field                               |"boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version"                                                          |Multivalue expression.
+mv_pseries_wei|[number, p]                         |[double, double]                                                                                                                  |[Multivalue expression., It is a constant number that represents the 'p' parameter in the P-Series. It impacts every element's contribution to the weighted sum.]
 mv_slice      |[field, start, end]                 |["boolean|cartesian_point|cartesian_shape|date|double|geo_point|geo_shape|integer|ip|keyword|long|text|version", integer, integer]|[Multivalue expression. If `null`\, the function returns `null`., Start position. If `null`\, the function returns `null`. The start argument can be negative. An index of -1 is used to specify the last value in the list., End position(included). Optional; if omitted\, the position at `start` is returned. The end argument can be negative. An index of -1 is used to specify the last value in the list.]
 mv_sort       |[field, order]                      |["boolean|date|double|integer|ip|keyword|long|text|version", keyword]                                                             |[Multivalue expression. If `null`\, the function returns `null`., Sort order. The valid options are ASC and DESC\, the default is ASC.]
 mv_sum        |number                              |"double|integer|long|unsigned_long"                                                                                               |Multivalue expression.
@@ -296,6 +298,7 @@ mv_last       |Converts a multivalue expression into a single valued column cont
 mv_max        |Converts a multivalued expression into a single valued column containing the maximum value.
 mv_median     |Converts a multivalued field into a single valued field containing the median value.
 mv_min        |Converts a multivalued expression into a single valued column containing the minimum value.
+mv_pseries_wei|Converts a multivalued expression into a single-valued column by multiplying every element on the input list by its corresponding term in P-Series and computing the sum.
 mv_slice      |Returns a subset of the multivalued field using the start and end index values.
 mv_sort       |Sorts a multivalued field in lexicographical order.
 mv_sum        |Converts a multivalued field into a single valued field containing the sum of all of the values.
@@ -419,6 +422,7 @@ mv_last       |"boolean|cartesian_point|cartesian_shape|date|double|geo_point|ge
 mv_max        |"boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version"                                                    |false                       |false           |false
 mv_median     |"double|integer|long|unsigned_long"                                                                                         |false                       |false           |false
 mv_min        |"boolean|date|double|integer|ip|keyword|long|text|unsigned_long|version"                                                    |false                       |false           |false
+mv_pseries_wei|"double"                                                                                                                    |[false, false]              |false           |false 
 mv_slice      |"boolean|cartesian_point|cartesian_shape|date|double|geo_point|geo_shape|integer|ip|keyword|long|text|version"              |[false, false, true]        |false           |false
 mv_sort       |"boolean|date|double|integer|ip|keyword|long|text|version"                                                                  |[false, true]               |false           |false
 mv_sum        |"double|integer|long|unsigned_long"                                                                                         |false                       |false           |false
@@ -497,5 +501,5 @@ countFunctions#[skip:-8.15.99]
 meta functions |  stats  a = count(*), b = count(*), c = count(*) |  mv_expand c;
 
 a:long | b:long | c:long
-113    | 113    | 113
+114    | 114    | 114
 ;

x-pack/plugin/esql/qa/testFixtures/src/main/resources/mv_pseries_weighted_sum.csv-spec

@@ -0,0 +1,89 @@
+default
+required_capability: mv_pseries_weighted_sum
+
+// tag::example[]
+ROW a = [70.0, 45.0, 21.0, 21.0, 21.0]
+| EVAL sum = MV_PSERIES_WEIGHTED_SUM(a, 1.5)
+| KEEP sum
+// end::example[]
+;
+
+// tag::example-result[]
+sum:double
+94.45465156212452
+// end::example-result[]
+;
+
+oneElement
+required_capability: mv_pseries_weighted_sum
+
+ROW data = [3.0]
+| EVAL score = MV_PSERIES_WEIGHTED_SUM(data, 9999.9)
+| KEEP score;
+
+score:double
+3.0
+;
+
+zeroP
+required_capability: mv_pseries_weighted_sum
+
+ROW data = [3.0, 10.0, 15.0]
+| EVAL score = MV_PSERIES_WEIGHTED_SUM(data, 0.0)
+| KEEP score;
+
+score:double
+28.0
+;
+
+negativeP
+required_capability: mv_pseries_weighted_sum
+
+ROW data = [10.0, 5.0, 3.0]
+| EVAL score = MV_PSERIES_WEIGHTED_SUM(data, -2.0)
+| KEEP score;
+
+score:double
+57.0
+;
+
+composed
+required_capability: mv_pseries_weighted_sum
+
+ROW data = [21.0, 45.0, 21.0, 70.0, 21.0]
+| EVAL sorted = MV_SORT(data, "desc")
+| EVAL score = MV_PSERIES_WEIGHTED_SUM(sorted, 1.5)
+| EVAL normalized_score = ROUND(100 * score / 261.2, 2)
+| KEEP normalized_score, score;
+
+normalized_score:double|score:double
+36.16                  |94.45465156212452
+;
+
+multivalueAggregation
+required_capability: mv_pseries_weighted_sum
+
+FROM alerts
+| WHERE host.name is not null
+| SORT host.name, kibana.alert.risk_score
+| STATS score=MV_PSERIES_WEIGHTED_SUM(
+    TOP(kibana.alert.risk_score, 10000, "desc"), 1.5
+) BY host.name
+| EVAL normalized_score = ROUND(100 * score / 261.2, 2)
+| KEEP host.name, normalized_score, score;
+
+host.name:keyword|normalized_score:double|score:double
+test-host-1      |36.16                  |94.45465156212452
+test-host-2      |13.03                  |34.036822671263614
+;
+
+asArgument
+required_capability: mv_pseries_weighted_sum
+
+ROW data = [70.0, 45.0, 21.0, 21.0, 21.0]
+| EVAL score = ROUND(MV_PSERIES_WEIGHTED_SUM(data, 1.5), 1)
+| KEEP score;
+
+score:double
+94.5
+;