ES|QL: Add (stack) telemetry for views

docs/changelog/143745.yaml

@@ -0,0 +1,5 @@
+area: ES|QL
+issues: []
+pr: 143745
+summary: Add (stack) telemetry for views
+type: enhancement

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plan/logical/Subquery.java

@@ -97,4 +97,8 @@ public String nodeString(NodeStringFormat format) {
     public LogicalPlan plan() {
         return child();
     }
+
+    public String name() {
+        return name;
+    }
 }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/session/EsqlSession.java

@@ -93,6 +93,7 @@
 import org.elasticsearch.xpack.esql.planner.premapper.PreMapper;
 import org.elasticsearch.xpack.esql.plugin.ComputeService;
 import org.elasticsearch.xpack.esql.plugin.TransportActionServices;
+import org.elasticsearch.xpack.esql.telemetry.FeatureMetric;
 import org.elasticsearch.xpack.esql.telemetry.Metrics;
 import org.elasticsearch.xpack.esql.telemetry.PlanTelemetry;
 import org.elasticsearch.xpack.esql.view.ViewResolver;
@@ -273,6 +274,7 @@ private void analyseAndExecute(
         ActionListener<Versioned<Result>> listener
     ) {
         assert ThreadPool.assertCurrentThreadPool(ThreadPool.Names.SEARCH);
+        gatherViewMetrics(viewResolution);
         PlanTimeProfile planTimeProfile = request.profile() ? new PlanTimeProfile() : null;
 
         ZoneId timeZone = request.timeZone() == null
@@ -719,6 +721,14 @@ private void gatherSettingsMetrics(EsqlStatement statement) {
         statement.settings().stream().map(QuerySetting::name).distinct().forEach(metrics::incSetting);
     }
 
+    private void gatherViewMetrics(ViewResolver.ViewResolutionResult viewResolution) {
+        if (metrics == null || viewResolution.viewQueries().isEmpty()) {
+            return;
+        }
+        // If any views were used, increment the views metric
+        metrics.inc(FeatureMetric.VIEWS);
+    }
+
     /**
      * Associates errors that occurred during field-caps with the cluster info in the execution info.
      * - Skips clusters that are no longer running, as they have already been marked as successful, skipped, or failed.

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/telemetry/FeatureMetric.java

@@ -86,7 +86,8 @@ public enum FeatureMetric {
     FUSE(Fuse.class::isInstance),
     COMPLETION(Completion.class::isInstance),
     SAMPLE(Sample.class::isInstance),
-    SUBQUERY(Subquery.class::isInstance),
+    SUBQUERY(plan -> plan instanceof Subquery s && s.name() == null),
+    VIEWS(plan -> false), // Views are counted in EsqlSession.gatherViewMetrics, not via plan traversal
     MMR(MMR.class::isInstance),
     PROMQL(PromqlCommand.class::isInstance),
     URI_PARTS(UriParts.class::isInstance),
@@ -129,6 +130,10 @@ public static void set(LogicalPlan plan, BitSet bitset) {
     }
 
     private static boolean explicitlyExcluded(LogicalPlan plan) {
+        // Named Subqueries represent views, which are counted separately in EsqlSession.gatherViewMetrics
+        if (plan instanceof Subquery s && s.name() != null) {
+            return true;
+        }
         return excluded.stream().anyMatch(x -> x.isInstance(plan));
     }
 

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/telemetry/VerifierMetricsTests.java

@@ -13,10 +13,14 @@
 import org.elasticsearch.xpack.core.watcher.common.stats.Counters;
 import org.elasticsearch.xpack.esql.action.EsqlCapabilities;
 import org.elasticsearch.xpack.esql.analysis.Verifier;
+import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.expression.function.EsqlFunctionRegistry;
 import org.elasticsearch.xpack.esql.expression.function.FunctionDefinition;
 import org.elasticsearch.xpack.esql.index.IndexResolution;
+import org.elasticsearch.xpack.esql.plan.logical.Row;
+import org.elasticsearch.xpack.esql.plan.logical.Subquery;
 
+import java.util.BitSet;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -47,6 +51,7 @@
 import static org.elasticsearch.xpack.esql.telemetry.FeatureMetric.SORT;
 import static org.elasticsearch.xpack.esql.telemetry.FeatureMetric.STATS;
 import static org.elasticsearch.xpack.esql.telemetry.FeatureMetric.TS;
+import static org.elasticsearch.xpack.esql.telemetry.FeatureMetric.VIEWS;
 import static org.elasticsearch.xpack.esql.telemetry.FeatureMetric.WHERE;
 import static org.elasticsearch.xpack.esql.telemetry.Metrics.FEATURES_PREFIX;
 import static org.elasticsearch.xpack.esql.telemetry.Metrics.FUNC_PREFIX;
@@ -839,6 +844,26 @@ public void testPromql() {
         assertEquals(0, subqueryInFromCommand(c));
     }
 
+    public void testSubqueryTelemetry() {
+        Row innerPlan = new Row(Source.EMPTY, List.of());
+
+        // A named Subquery represents a view - it should be excluded from plan traversal telemetry
+        // Views are counted separately via EsqlSession.gatherViewMetrics (ad-hoc approach)
+        Subquery view = new Subquery(Source.EMPTY, innerPlan, "my_view");
+        BitSet viewBitSet = new BitSet();
+        FeatureMetric.set(view, viewBitSet);
+        // Named Subqueries are excluded, so no metrics should be set
+        assertFalse("VIEWS should not be set for named Subquery (counted ad-hoc)", viewBitSet.get(VIEWS.ordinal()));
+        assertFalse("SUBQUERY should not be set for named Subquery", viewBitSet.get(FeatureMetric.SUBQUERY.ordinal()));
+
+        // An unnamed Subquery represents an inline subquery (not a view)
+        Subquery subquery = new Subquery(Source.EMPTY, innerPlan);
+        BitSet subqueryBitSet = new BitSet();
+        FeatureMetric.set(subquery, subqueryBitSet);
+        assertFalse("VIEWS should not be set for unnamed Subquery", subqueryBitSet.get(VIEWS.ordinal()));
+        assertTrue("SUBQUERY should be set for unnamed Subquery", subqueryBitSet.get(FeatureMetric.SUBQUERY.ordinal()));
+    }
+
     private long dissect(Counters c) {
         return c.get(FEATURES_PREFIX + DISSECT);
     }
@@ -923,6 +948,10 @@ private long subqueryInFromCommand(Counters c) {
         return c.get(FEATURES_PREFIX + FeatureMetric.SUBQUERY);
     }
 
+    private long views(Counters c) {
+        return c.get(FEATURES_PREFIX + VIEWS);
+    }
+
     private long function(String function, Counters c) {
         return c.get(FUNC_PREFIX + function);
     }

x-pack/plugin/src/yamlRestTest/resources/rest-api-spec/test/esql/60_usage.yml

@@ -97,6 +97,7 @@ setup:
   - set: { esql.features.completion: completion_counter }
   - set: { esql.features.sample: sample_counter }
   - set: { esql.features.subquery: subquery_counter }
+  - set: { esql.features.views: views_counter }
   - set: { esql.features.uri_parts: uri_parts_counter }
   - set: { esql.features.registered_domain: registered_domain_counter }
   - set: { esql.features.mmr: mmr_counter }
@@ -402,3 +403,40 @@ took:
   - exists: esql.took.lt_10h
   - exists: esql.took.lt_1d
   - exists: esql.took.gt_1d
+
+---
+"Views telemetry (snapshot only)":
+  - requires:
+      test_runner_features: [ capabilities ]
+      capabilities:
+        - method: POST
+          path: /_query
+          parameters: [ ]
+          capabilities: [ snapshot_test_for_telemetry_v2 ]
+        - method: GET
+          path: /_query/view
+          capabilities: [ view_index_abstraction ]
+      reason: "Views telemetry test requires snapshot build with views enabled"
+
+  - do: { xpack.usage: { } }
+  - set: { esql.features.views: views_counter }
+  - set: { esql.features.subquery: subquery_counter }
+
+  - do:
+      esql.put_view:
+        name: test_view_for_telemetry
+        body:
+          query: 'FROM test | WHERE data > 0'
+
+  - do:
+      esql.query:
+        body:
+          query: 'FROM test_view_for_telemetry | LIMIT 10'
+
+  - do: { xpack.usage: { } }
+  - gt: { esql.features.views: $views_counter }
+  - match: { esql.features.subquery: $subquery_counter }
+
+  - do:
+      esql.delete_view:
+        name: test_view_for_telemetry