log.warn anytime a column is relying on ArrayIngestMode.MVD (#17164)

* log.warn anytime a column is relying on ArrayIngestMode.MVD

extensions-core/multi-stage-query/src/main/java/org/apache/druid/msq/sql/MSQTaskSqlEngine.java

@@ -387,7 +387,7 @@ public class MSQTaskSqlEngine implements SqlEngine
         final ColumnType oldDruidType = Calcites.getColumnTypeForRelDataType(oldSqlTypeField.getType());
         final RelDataType newSqlType = rootRel.getRowType().getFieldList().get(columnIndex).getType();
         final ColumnType newDruidType =
-            DimensionSchemaUtils.getDimensionType(Calcites.getColumnTypeForRelDataType(newSqlType), arrayIngestMode);
+            DimensionSchemaUtils.getDimensionType(columnName, Calcites.getColumnTypeForRelDataType(newSqlType), arrayIngestMode);
 
         if (newDruidType.isArray() && oldDruidType.is(ValueType.STRING)
             || (newDruidType.is(ValueType.STRING) && oldDruidType.isArray())) {

extensions-core/multi-stage-query/src/main/java/org/apache/druid/msq/util/DimensionSchemaUtils.java

@@ -27,6 +27,8 @@ import org.apache.druid.data.input.impl.StringDimensionSchema;
 import org.apache.druid.error.InvalidInput;
 import org.apache.druid.java.util.common.ISE;
 import org.apache.druid.java.util.common.StringUtils;
+import org.apache.druid.java.util.emitter.EmittingLogger;
+import org.apache.druid.java.util.emitter.service.AlertEvent;
 import org.apache.druid.segment.AutoTypeColumnSchema;
 import org.apache.druid.segment.DimensionHandlerUtils;
 import org.apache.druid.segment.column.ColumnCapabilities;
@@ -42,6 +44,7 @@ import javax.annotation.Nullable;
  */
 public class DimensionSchemaUtils
 {
+  private static final EmittingLogger LOG = new EmittingLogger(DimensionSchemaUtils.class);
 
   /**
    * Creates a dimension schema for creating {@link org.apache.druid.data.input.InputSourceReader}.
@@ -89,7 +92,7 @@ public class DimensionSchemaUtils
       return new AutoTypeColumnSchema(column, null);
     } else {
       // dimensionType may not be identical to queryType, depending on arrayIngestMode.
-      final ColumnType dimensionType = getDimensionType(queryType, arrayIngestMode);
+      final ColumnType dimensionType = getDimensionType(column, queryType, arrayIngestMode);
 
       if (dimensionType.getType() == ValueType.STRING) {
         return new StringDimensionSchema(
@@ -121,6 +124,7 @@ public class DimensionSchemaUtils
    * @throws org.apache.druid.error.DruidException if there is some problem
    */
   public static ColumnType getDimensionType(
+      final String columnName,
       @Nullable final ColumnType queryType,
       final ArrayIngestMode arrayIngestMode
   )
@@ -132,6 +136,13 @@ public class DimensionSchemaUtils
       ValueType elementType = queryType.getElementType().getType();
       if (elementType == ValueType.STRING) {
         if (arrayIngestMode == ArrayIngestMode.MVD) {
+          final String msgFormat = "Inserting a multi-value string column[%s] relying on deprecated"
+                                   + " ArrayIngestMode.MVD. This query should be rewritten to use the ARRAY_TO_MV"
+                                   + " operator to insert ARRAY types as multi-value strings.";
+          LOG.makeWarningAlert(msgFormat, columnName)
+             .severity(AlertEvent.Severity.DEPRECATED)
+             .addData("feature", "ArrayIngestMode.MVD")
+             .emit();
           return ColumnType.STRING;
         } else {
           return queryType;

indexing-service/src/test/java/org/apache/druid/indexing/overlord/RemoteTaskRunnerTest.java

@@ -1073,7 +1073,7 @@ public class RemoteTaskRunnerTest
     EasyMock.expect(worker.getHost()).andReturn("host").atLeastOnce();
     EasyMock.replay(worker);
     ServiceEmitter emitter = EasyMock.createMock(ServiceEmitter.class);
-    Capture<EmittingLogger.EmittingAlertBuilder> capturedArgument = Capture.newInstance();
+    Capture<EmittingLogger.LoggingAlertBuilder> capturedArgument = Capture.newInstance();
     emitter.emit(EasyMock.capture(capturedArgument));
     EasyMock.expectLastCall().atLeastOnce();
     EmittingLogger.registerEmitter(emitter);

processing/src/main/java/org/apache/druid/java/util/emitter/EmittingLogger.java

@@ -29,8 +29,11 @@ import org.apache.druid.java.util.emitter.service.AlertBuilder;
 import org.apache.druid.java.util.emitter.service.ServiceEmitter;
 
 import javax.annotation.Nullable;
+import java.util.Map;
 
 /**
+ * {@link Logger} which also has an {@link ServiceEmitter}. Primarily useful for constructing and emitting "alerts" in
+ * the form of {@link AlertBuilder}, which will log when {@link AlertBuilder#emit()} is called.
  */
 public class EmittingLogger extends Logger
 {
@@ -62,12 +65,34 @@ public class EmittingLogger extends Logger
     return new EmittingLogger(getSlf4jLogger(), false);
   }
 
-  public AlertBuilder makeAlert(String message, Object... objects)
+  /**
+   * Make an {@link AlertBuilder} which will call {@link #warn(String, Object...)} when {@link AlertBuilder#emit()} is
+   * called.
+   */
+  public AlertBuilder makeWarningAlert(String message, Object... objects)
   {
-    return makeAlert(null, message, objects);
+    return makeAlert(null, false, message, objects);
   }
 
+  /**
+   * Make an {@link AlertBuilder} which will call {@link #error(String, Object...)} when {@link AlertBuilder#emit()} is
+   * called.
+   */
+  public AlertBuilder makeAlert(String message, Object... objects)
+  {
+    return makeAlert(null, true, message, objects);
+  }
+
+  /**
+   * Make an {@link AlertBuilder} which will call {@link #error(Throwable, String, Object...)} when
+   * {@link AlertBuilder#emit()} is called.
+   */
   public AlertBuilder makeAlert(@Nullable Throwable t, String message, Object... objects)
+  {
+    return makeAlert(t, true, message, objects);
+  }
+
+  public AlertBuilder makeAlert(@Nullable Throwable t, boolean isError, String message, Object... objects)
   {
     if (emitter == null) {
       final String errorMessage = StringUtils.format(
@@ -87,20 +112,22 @@ public class EmittingLogger extends Logger
       throw e;
     }
 
-    return new EmittingAlertBuilder(t, StringUtils.format(message, objects), emitter)
+    return new LoggingAlertBuilder(t, StringUtils.format(message, objects), emitter, isError)
         .addData("class", className);
   }
 
-  public class EmittingAlertBuilder extends AlertBuilder
+  public class LoggingAlertBuilder extends AlertBuilder
   {
     private final Throwable t;
+    private final boolean isError;
 
     private volatile boolean emitted = false;
 
-    private EmittingAlertBuilder(Throwable t, String description, ServiceEmitter emitter)
+    private LoggingAlertBuilder(Throwable t, String description, ServiceEmitter emitter, boolean isError)
     {
       super(description, emitter);
       this.t = t;
+      this.isError = isError;
       addThrowable(t);
     }
 
@@ -126,15 +153,22 @@ public class EmittingLogger extends Logger
     private void logIt(String format)
     {
       if (t == null) {
-        error(format, description, dataMap);
+        if (isError) {
+          error(format, description, dataMap);
+        } else {
+          warn(format, description, dataMap);
+        }
       } else {
         // Filter out the stack trace from the message, because it should be in the logline already if it's wanted.
-        error(
+        final Map<String, Object> filteredDataMap = Maps.filterKeys(
-            t,
+            dataMap,
-            format,
+            Predicates.not(Predicates.equalTo("exceptionStackTrace"))
-            description,
-            Maps.filterKeys(dataMap, Predicates.not(Predicates.equalTo("exceptionStackTrace")))
         );
+        if (isError) {
+          error(t, format, description, filteredDataMap);
+        } else {
+          warn(t, format, description, filteredDataMap);
+        }
       }
     }
   }

processing/src/main/java/org/apache/druid/java/util/emitter/service/AlertEvent.java

@@ -186,6 +186,13 @@ public class AlertEvent implements Event
       {
         return "service-failure";
       }
+    },
+    DEPRECATED {
+      @Override
+      public String toString()
+      {
+        return "deprecated";
+      }
     };
 
     public static final Severity DEFAULT = COMPONENT_FAILURE;