[HUDI-2244] Fix database alreadyExists exception while hive sync (#3361)

hudi-sync/hudi-hive-sync/src/main/java/org/apache/hudi/hive/HiveSyncTool.java

@@ -150,7 +150,9 @@ public class HiveSyncTool extends AbstractSyncTool {
     // check if the database exists else create it
     if (cfg.autoCreateDatabase) {
       try {
+        if (!hoodieHiveClient.doesDataBaseExist(cfg.databaseName)) {
           hoodieHiveClient.createDatabase(cfg.databaseName);
+        }
       } catch (Exception e) {
         // this is harmless since table creation will fail anyways, creation of DB is needed for in-memory testing
         LOG.warn("Unable to create database", e);

hudi-sync/hudi-hive-sync/src/main/java/org/apache/hudi/hive/HoodieHiveClient.java

@@ -33,7 +33,6 @@ import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hive.conf.HiveConf;
 import org.apache.hadoop.hive.metastore.IMetaStoreClient;
-import org.apache.hadoop.hive.metastore.api.Database;
 import org.apache.hadoop.hive.metastore.api.NoSuchObjectException;
 import org.apache.hadoop.hive.metastore.api.Partition;
 import org.apache.hadoop.hive.metastore.api.Table;
@@ -221,14 +220,14 @@ public class HoodieHiveClient extends AbstractSyncHoodieClient {
    */
   public boolean doesDataBaseExist(String databaseName) {
     try {
-      Database database = client.getDatabase(databaseName);
+      client.getDatabase(databaseName);
-      if (database != null && databaseName.equals(database.getName())) {
       return true;
-      }
+    } catch (NoSuchObjectException noSuchObjectException) {
+      // NoSuchObjectException is thrown when there is no existing database of the name.
+      return false;
     } catch (TException e) {
       throw new HoodieHiveSyncException("Failed to check if database exists " + databaseName, e);
     }
-    return false;
   }
 
   public void createDatabase(String databaseName) {

hudi-sync/hudi-hive-sync/src/test/java/org/apache/hudi/hive/TestHiveSyncTool.java

@@ -62,8 +62,10 @@ import java.util.Map;
 import static org.apache.hudi.hive.testutils.HiveTestUtil.ddlExecutor;
 import static org.apache.hudi.hive.testutils.HiveTestUtil.fileSystem;
 import static org.apache.hudi.hive.testutils.HiveTestUtil.hiveSyncConfig;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class TestHiveSyncTool {
@@ -302,6 +304,49 @@ public class TestHiveSyncTool {
         "The last commit that was synced should be 100");
   }
 
+  @ParameterizedTest
+  @MethodSource({"syncMode"})
+  public void testSyncDataBase(String syncMode) throws Exception {
+    hiveSyncConfig.syncMode = syncMode;
+    HiveTestUtil.hiveSyncConfig.batchSyncNum = 3;
+    String instantTime = "100";
+    HiveTestUtil.createCOWTable(instantTime, 5, true);
+    hiveSyncConfig.databaseName = "database1";
+
+    // while autoCreateDatabase is false and database not exists;
+    hiveSyncConfig.autoCreateDatabase = false;
+    // Lets do the sync
+    assertThrows(Exception.class, () -> {
+      new HiveSyncTool(hiveSyncConfig, HiveTestUtil.getHiveConf(), fileSystem).syncHoodieTable();
+    });
+
+    // while autoCreateDatabase is true and database not exists;
+    hiveSyncConfig.autoCreateDatabase = true;
+    HoodieHiveClient hiveClient =
+        new HoodieHiveClient(HiveTestUtil.hiveSyncConfig, HiveTestUtil.getHiveConf(), fileSystem);
+    assertDoesNotThrow(() -> {
+      new HiveSyncTool(hiveSyncConfig, HiveTestUtil.getHiveConf(), fileSystem).syncHoodieTable();
+    });
+    assertTrue(hiveClient.doesDataBaseExist(hiveSyncConfig.databaseName),
+        "DataBases " + hiveSyncConfig.databaseName + " should exist after sync completes");
+
+    // while autoCreateDatabase is false and database exists;
+    hiveSyncConfig.autoCreateDatabase = false;
+    assertDoesNotThrow(() -> {
+      new HiveSyncTool(hiveSyncConfig, HiveTestUtil.getHiveConf(), fileSystem).syncHoodieTable();
+    });
+    assertTrue(hiveClient.doesDataBaseExist(hiveSyncConfig.databaseName),
+        "DataBases " + hiveSyncConfig.databaseName + " should exist after sync completes");
+
+    // while autoCreateDatabase is true and database exists;
+    hiveSyncConfig.autoCreateDatabase = true;
+    assertDoesNotThrow(() -> {
+      new HiveSyncTool(hiveSyncConfig, HiveTestUtil.getHiveConf(), fileSystem).syncHoodieTable();
+    });
+    assertTrue(hiveClient.doesDataBaseExist(hiveSyncConfig.databaseName),
+        "DataBases " + hiveSyncConfig.databaseName + " should exist after sync completes");
+  }
+
   @ParameterizedTest
   @MethodSource({"syncDataSourceTableParams"})
   public void testSyncCOWTableWithProperties(boolean useSchemaFromCommitMetadata,
@@ -1054,6 +1099,8 @@ public class TestHiveSyncTool {
     hiveSyncConfig.syncMode = syncMode;
     HiveTestUtil.hiveSyncConfig.batchSyncNum = 2;
     HiveTestUtil.createCOWTable("100", 5, true);
+    // create database.
+    ddlExecutor.runSQL("create database " + hiveSyncConfig.databaseName);
     HoodieHiveClient hiveClient =
         new HoodieHiveClient(HiveTestUtil.hiveSyncConfig, HiveTestUtil.getHiveConf(), HiveTestUtil.fileSystem);
     String tableName = HiveTestUtil.hiveSyncConfig.tableName;

hudi-sync/hudi-hive-sync/src/test/java/org/apache/hudi/hive/testutils/HiveTestUtil.java

@@ -138,8 +138,7 @@ public class HiveTestUtil {
       ddlExecutor.runSQL("drop table if exists " + tableName);
     }
     createdTablesSet.clear();
-    ddlExecutor.runSQL("drop database if exists " + hiveSyncConfig.databaseName);
+    ddlExecutor.runSQL("drop database if exists " + hiveSyncConfig.databaseName + " cascade");
-    ddlExecutor.runSQL("create database " + hiveSyncConfig.databaseName);
   }
 
   public static HiveConf getHiveConf() {