Warn users when using morsel runtime

community/common/src/main/java/org/neo4j/kernel/api/exceptions/Status.java

@@ -265,6 +265,8 @@ enum Statement implements Status
                 "This query is not supported by the chosen runtime." ),
         FeatureDeprecationWarning( ClientNotification,
                 "This feature is deprecated and will be removed in future versions." ),
+        ExperimentalFeature( ClientNotification,
+                "This feature is experimental and should not be used in production systems." ),
         JoinHintUnsupportedWarning( ClientNotification,
                 "Queries with join hints are not supported by the RULE planner." ),
 

community/cypher/cypher/src/main/scala/org/neo4j/cypher/internal/CompilerEngineDelegator.scala

@@ -21,14 +21,14 @@ package org.neo4j.cypher.internal
 
 import java.time.Clock
 
-import org.neo4j.cypher.internal.util.v3_4.InputPosition
 import org.neo4j.cypher.internal.compiler.v3_4.CypherCompilerConfiguration
 import org.neo4j.cypher.internal.frontend.v3_4.helpers.fixedPoint
 import org.neo4j.cypher.internal.frontend.v3_4.phases.CompilationPhaseTracer
+import org.neo4j.cypher.internal.util.v3_4.InputPosition
 import org.neo4j.cypher.{InvalidArgumentException, SyntaxException, exceptionHandler, _}
 import org.neo4j.graphdb.factory.GraphDatabaseSettings
 import org.neo4j.graphdb.impl.notification.NotificationCode.{CREATE_UNIQUE_UNAVAILABLE_FALLBACK, RULE_PLANNER_UNAVAILABLE_FALLBACK, START_DEPRECATED, START_UNAVAILABLE_FALLBACK}
-import org.neo4j.graphdb.impl.notification.NotificationDetail.Factory.startDeprecated
+import org.neo4j.graphdb.impl.notification.NotificationDetail.Factory.message
 import org.neo4j.kernel.GraphDatabaseQueryService
 import org.neo4j.kernel.api.KernelAPI
 import org.neo4j.kernel.configuration.Config
@@ -202,7 +202,7 @@ class CompilerEngineDelegator(graph: GraphDatabaseQueryService,
 
   private def createStartDeprecatedNotification(ex: util.v3_4.SyntaxException, preParsedQuery: PreParsedQuery) = {
     val pos = convertInputPosition(ex.pos.getOrElse(preParsedQuery.offset))
-    START_DEPRECATED.notification(pos, startDeprecated(ex.getMessage))
+    START_DEPRECATED.notification(pos, message("START", ex.getMessage))
   }
 
   private def createUniqueNotification(ex: util.v3_4.SyntaxException, preParsedQuery: PreParsedQuery) = {

community/cypher/cypher/src/main/scala/org/neo4j/cypher/internal/compatibility/v3_4/runtime/helpers/InternalWrapping.scala

@@ -19,8 +19,8 @@
  */
 package org.neo4j.cypher.internal.compatibility.v3_4.runtime.helpers
 
-import org.neo4j.cypher.internal.util.v3_4.InputPosition
 import org.neo4j.cypher.internal.frontend.v3_4.notification.{DeprecatedPlannerNotification, InternalNotification, PlannerUnsupportedNotification, RuntimeUnsupportedNotification, _}
+import org.neo4j.cypher.internal.util.v3_4.InputPosition
 import org.neo4j.graphdb
 import org.neo4j.graphdb.impl.notification.{NotificationCode, NotificationDetail}
 
@@ -30,7 +30,7 @@ object InternalWrapping {
 
   def asKernelNotification(offset: Option[InputPosition])(notification: InternalNotification) = notification match {
     case DeprecatedStartNotification(pos, message) =>
-      NotificationCode.START_DEPRECATED.notification(pos.withOffset(offset).asInputPosition, NotificationDetail.Factory.startDeprecated(message))
+      NotificationCode.START_DEPRECATED.notification(pos.withOffset(offset).asInputPosition, NotificationDetail.Factory.message("START", message))
     case CartesianProductNotification(pos, variables) =>
       NotificationCode.CARTESIAN_PRODUCT.notification(pos.withOffset(offset).asInputPosition, NotificationDetail.Factory.cartesianProduct(variables.asJava))
     case LengthOnNonPathNotification(pos) =>
@@ -75,6 +75,8 @@ object InternalWrapping {
       NotificationCode.DEPRECATED_PLANNER.notification(graphdb.InputPosition.empty)
     case ProcedureWarningNotification(pos, name, warning) =>
       NotificationCode.PROCEDURE_WARNING.notification(pos.withOffset(offset).asInputPosition, NotificationDetail.Factory.procedureWarning(name, warning))
+    case ExperimentalFeatureNotification(msg) =>
+      NotificationCode.EXPERIMENTAL_FEATURE.notification(graphdb.InputPosition.empty, NotificationDetail.Factory.message("MORSEL", msg))
   }
 
   private implicit class ConvertibleCompilerInputPosition(pos: InputPosition) {

community/cypher/frontend-3.4/src/main/scala/org/neo4j/cypher/internal/frontend/v3_4/notification/InternalNotification.scala

@@ -68,3 +68,5 @@ case class DeprecatedVarLengthBindingNotification(position: InputPosition, varia
 case class DeprecatedRelTypeSeparatorNotification(position: InputPosition) extends InternalNotification
 
 case object DeprecatedPlannerNotification extends InternalNotification
+
+case class ExperimentalFeatureNotification(msg: String) extends InternalNotification

community/kernel/src/main/java/org/neo4j/graphdb/impl/notification/NotificationCode.java

@@ -189,8 +189,11 @@ public enum NotificationCode
     START_DEPRECATED(
             SeverityLevel.WARNING,
             Status.Statement.FeatureDeprecationWarning,
-            "START has been deprecated and will be removed in a future version."
-    );
+            "START has been deprecated and will be removed in a future version."),
+    EXPERIMENTAL_FEATURE(
+            SeverityLevel.WARNING,
+            Status.Statement.ExperimentalFeature,
+            "You are using an experimental feature");
 
     private final Status status;
     private final String description;

community/kernel/src/main/java/org/neo4j/graphdb/impl/notification/NotificationDetail.java

@@ -102,14 +102,14 @@ public static NotificationDetail indexSeekOrScan( Set<String> labels )
             return createNotificationDetail( labels, "indexed label", "indexed labels" );
         }
 
-        public static NotificationDetail startDeprecated( String message )
+        public static NotificationDetail message( String name, String message )
         {
             return new NotificationDetail()
             {
                 @Override
                 public String name()
                 {
-                    return "START";
+                    return name;
                 }
 
                 @Override

enterprise/cypher/acceptance-spec-suite/src/test/scala/org/neo4j/internal/cypher/acceptance/MorselRuntimeAcceptanceTest.scala

@@ -56,5 +56,18 @@ class MorselRuntimeAcceptanceTest extends ExecutionEngineFunSuite {
     result.getExecutionPlanDescription.getArguments.get("runtime") should not equal "MORSEL"
   }
 
+  test("should warn that morsels are experimental") {
+    //Given
+    import scala.collection.JavaConverters._
+
+    val result = graph.execute("CYPHER runtime=morsel EXPLAIN MATCH (n) RETURN n")
+
+    // When (exhaust result)
+    val notifications = result.getNotifications.asScala.toSet
 
+    //Then
+    notifications.head.getDescription should equal("You are using an experimental feature (use the morsel runtime at " +
+                                                     "your own peril, not recommended to be run on production systems)")
+
+  }
 }

enterprise/cypher/cypher/src/main/scala/org/neo4j/cypher/internal/BuildVectorizedExecutionPlan.scala

@@ -24,14 +24,15 @@ import org.neo4j.cypher.internal.compatibility.v3_4.runtime._
 import org.neo4j.cypher.internal.compatibility.v3_4.runtime.compiled.EnterpriseRuntimeContext
 import org.neo4j.cypher.internal.compatibility.v3_4.runtime.executionplan.StandardInternalExecutionResult.IterateByAccepting
 import org.neo4j.cypher.internal.compatibility.v3_4.runtime.executionplan.{NewRuntimeSuccessRateMonitor, StandardInternalExecutionResult}
+import org.neo4j.cypher.internal.compatibility.v3_4.runtime.helpers.InternalWrapping.asKernelNotification
 import org.neo4j.cypher.internal.compatibility.v3_4.runtime.phases.CompilationState
 import org.neo4j.cypher.internal.compatibility.v3_4.runtime.slotted.expressions.SlottedExpressionConverters
 import org.neo4j.cypher.internal.compiler.v3_4.phases.LogicalPlanState
 import org.neo4j.cypher.internal.compiler.v3_4.planner.CantCompileQueryException
 import org.neo4j.cypher.internal.frontend.v3_4.PlannerName
-import org.neo4j.cypher.internal.frontend.v3_4.notification.InternalNotification
+import org.neo4j.cypher.internal.frontend.v3_4.notification.{ExperimentalFeatureNotification, InternalNotification}
 import org.neo4j.cypher.internal.frontend.v3_4.phases.CompilationPhaseTracer.CompilationPhase
-import org.neo4j.cypher.internal.frontend.v3_4.phases.{CompilationPhaseTracer, Condition, Phase}
+import org.neo4j.cypher.internal.frontend.v3_4.phases.{CompilationPhaseTracer, Condition, InternalNotificationLogger, Phase}
 import org.neo4j.cypher.internal.planner.v3_4.spi.{GraphStatistics, PlanContext}
 import org.neo4j.cypher.internal.runtime.interpreted.commands.convert.{CommunityExpressionConverter, ExpressionConverters}
 import org.neo4j.cypher.internal.runtime.planDescription.InternalPlanDescription.Arguments.{Runtime, RuntimeImpl}
@@ -63,8 +64,11 @@ object BuildVectorizedExecutionPlan extends Phase[EnterpriseRuntimeContext, Logi
         else context.dispatcher
       val fieldNames = from.statement().returnColumns.toArray
 
+      context.notificationLogger.log(
+        ExperimentalFeatureNotification("use the morsel runtime at your own peril, " +
+                                          "not recommended to be run on production systems"))
       val execPlan = VectorizedExecutionPlan(from.plannerName, operators, pipelines, physicalPlan, fieldNames,
-                                             dispatcher)
+                                             dispatcher, context.notificationLogger)
       runtimeSuccessRateMonitor.newPlanSeen(from.logicalPlan)
       new CompilationState(from, Some(execPlan))
     } catch {
@@ -88,7 +92,8 @@ object BuildVectorizedExecutionPlan extends Phase[EnterpriseRuntimeContext, Logi
                                      pipelineInformation: Map[LogicalPlanId, PipelineInformation],
                                      physicalPlan: LogicalPlan,
                                      fieldNames: Array[String],
-                                     dispatcher: Dispatcher) extends executionplan.ExecutionPlan {
+                                     dispatcher: Dispatcher,
+                                     notificationLogger: InternalNotificationLogger) extends executionplan.ExecutionPlan {
     override def run(queryContext: QueryContext, planType: ExecutionMode, params: MapValue): InternalExecutionResult = {
       val taskCloser = new TaskCloser
       taskCloser.addTask(queryContext.transactionalContext.close)
@@ -97,9 +102,15 @@ object BuildVectorizedExecutionPlan extends Phase[EnterpriseRuntimeContext, Logi
           .addArgument(Runtime(MorselRuntimeName.toTextOutput))
           .addArgument(RuntimeImpl(MorselRuntimeName.name))
 
-      new VectorizedOperatorExecutionResult(operators, physicalPlan, planDescription, queryContext,
-                                            params, fieldNames, taskCloser, dispatcher)
-    }
+      if (planType == ExplainMode) {
+        //close all statements
+        taskCloser.close(success = true)
+        ExplainExecutionResult(fieldNames, planDescription(), READ_ONLY,
+                               notificationLogger.notifications.map(asKernelNotification(notificationLogger.offset)))
+      } else new VectorizedOperatorExecutionResult(operators, physicalPlan, planDescription, queryContext,
+                                              params, fieldNames, taskCloser, dispatcher)
+      }
+
 
     override def isPeriodicCommit: Boolean = false
 
@@ -133,7 +144,7 @@ class VectorizedOperatorExecutionResult(operators: Pipeline,
 
   override def executionMode: ExecutionMode = NormalMode
 
-  override def notifications: Iterable[Notification] = ???
+  override def notifications: Iterable[Notification] = Iterable.empty[Notification]
 
   override def withNotifications(notification: Notification*): InternalExecutionResult = this
 }