[ES|QL] add validation_only option

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/EsqlQueryRequest.java

@@ -50,6 +50,7 @@ public class EsqlQueryRequest extends org.elasticsearch.xpack.core.esql.action.E
     private TimeValue waitForCompletionTimeout = DEFAULT_WAIT_FOR_COMPLETION;
     private TimeValue keepAlive = DEFAULT_KEEP_ALIVE;
     private boolean keepOnCompletion;
+    private boolean validationOnly;
     private boolean onSnapshotBuild = Build.current().isSnapshot();
     private boolean acceptedPragmaRisks = false;
     private Boolean allowPartialResults = null;
@@ -202,6 +203,14 @@ public void keepOnCompletion(boolean keepOnCompletion) {
         this.keepOnCompletion = keepOnCompletion;
     }
 
+    public boolean validationOnly() {
+        return validationOnly;
+    }
+
+    public void validationOnly(boolean validationOnly) {
+        this.validationOnly = validationOnly;
+    }
+
     /**
      * Add a "table" to the request for use with things like {@code LOOKUP}.
      */

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/RequestXContent.java

@@ -85,6 +85,7 @@ String fields() {
     static final ParseField WAIT_FOR_COMPLETION_TIMEOUT = new ParseField("wait_for_completion_timeout");
     static final ParseField KEEP_ALIVE = new ParseField("keep_alive");
     static final ParseField KEEP_ON_COMPLETION = new ParseField("keep_on_completion");
+    static final ParseField VALIDATION_ONLY = new ParseField("validation_only");
 
     private static final ObjectParser<EsqlQueryRequest, Void> SYNC_PARSER = objectParserSync(EsqlQueryRequest::syncEsqlQueryRequest);
     private static final ObjectParser<EsqlQueryRequest, Void> ASYNC_PARSER = objectParserAsync(EsqlQueryRequest::asyncEsqlQueryRequest);
@@ -114,6 +115,7 @@ private static void objectParserCommon(ObjectParser<EsqlQueryRequest, ?> parser)
         parser.declareString((request, localeTag) -> request.locale(Locale.forLanguageTag(localeTag)), LOCALE_FIELD);
         parser.declareBoolean(EsqlQueryRequest::profile, PROFILE_FIELD);
         parser.declareField((p, r, c) -> new ParseTables(r, p).parseTables(), TABLES_FIELD, ObjectParser.ValueType.OBJECT);
+        parser.declareBoolean(EsqlQueryRequest::validationOnly, VALIDATION_ONLY);
     }
 
     private static ObjectParser<EsqlQueryRequest, Void> objectParserSync(Supplier<EsqlQueryRequest> supplier) {

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

@@ -250,7 +250,7 @@ private void innerExecute(Task task, EsqlQueryRequest request, ActionListener<Es
             services,
             ActionListener.wrap(result -> {
                 recordCCSTelemetry(task, executionInfo, request, null);
-                planExecutor.metrics().recordTook(executionInfo.overallTook().millis());
+                // planExecutor.metrics().recordTook(executionInfo.overallTook().millis());
                 listener.onResponse(toResponse(task, request, configuration, result));
             }, ex -> {
                 recordCCSTelemetry(task, executionInfo, request, ex);

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/querylog/EsqlQueryLog.java

@@ -15,6 +15,7 @@
 import org.elasticsearch.index.SlowLogFieldProvider;
 import org.elasticsearch.index.SlowLogFields;
 import org.elasticsearch.xcontent.json.JsonStringEncoder;
+import org.elasticsearch.xpack.esql.action.EsqlExecutionInfo;
 import org.elasticsearch.xpack.esql.session.Result;
 
 import java.nio.charset.StandardCharsets;
@@ -66,7 +67,8 @@ public void onQueryPhase(Result esqlResult, String query) {
         if (esqlResult == null) {
             return; // TODO review, it happens in some tests, not sure if it's a thing also in prod
         }
-        long tookInNanos = esqlResult.executionInfo().overallTook().nanos();
+        EsqlExecutionInfo executionResult = esqlResult.executionInfo();
+        long tookInNanos = executionResult == null ? 0 : executionResult.overallTook().nanos();
         log(() -> Message.of(esqlResult, query, includeUser ? additionalFields.queryFields() : Map.of()), tookInNanos);
     }
 

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

@@ -181,12 +181,13 @@ public void execute(EsqlQueryRequest request, EsqlExecutionInfo executionInfo, P
             new EsqlCCSUtils.CssPartialErrorsActionListener(executionInfo, listener) {
                 @Override
                 public void onResponse(LogicalPlan analyzedPlan) {
-                    preMapper.preMapper(
-                        analyzedPlan,
-                        listener.delegateFailureAndWrap(
-                            (l, p) -> executeOptimizedPlan(request, executionInfo, planRunner, optimizedPlan(p), l)
-                        )
-                    );
+                    preMapper.preMapper(analyzedPlan, listener.delegateFailureAndWrap((l, p) -> {
+                        if (request.validationOnly()) {
+                            l.onResponse(new Result(new ArrayList<>(), new ArrayList<>(), DriverCompletionInfo.EMPTY, null));
+                        } else {
+                            executeOptimizedPlan(request, executionInfo, planRunner, optimizedPlan(p), l);
+                        }
+                    }));
                 }
             }
         );