[PLAT-15297][dr] GET /configs fails with java.lang.IllegalStateExcept…

…ion: DrConfig iTest-dr(uuid) does not have any corresponding xCluster config

Summary:
This diff moves the delete DR config entry to a transaction with deleting the last xCluster config entry of that DR config.

It also removes `XClusterConfigTaskBase.getTableInfoList(ybService, sourceUniverse);` from the failover controller.

Test Plan:
- Made sure a failover task succeeds when the source universe is down.
- Made sure the DR config is deleted properly when the source universe is deleted even when the dr config has two xCluster config entries.

Reviewers: #yba-api-review!, vbansal, cwang, jmak, sanketh

Reviewed By: vbansal

Subscribers: yugaware

Differential Revision: https://phorge.dev.yugabyte.com/D38151

managed/src/main/java/com/yugabyte/yw/commissioner/tasks/DeleteDrConfig.java

@@ -3,7 +3,6 @@
 
 import com.yugabyte.yw.commissioner.BaseTaskDependencies;
 import com.yugabyte.yw.commissioner.UserTaskDetails;
-import com.yugabyte.yw.commissioner.UserTaskDetails.SubTaskGroupType;
 import com.yugabyte.yw.common.XClusterUniverseService;
 import com.yugabyte.yw.forms.DrConfigTaskParams;
 import com.yugabyte.yw.models.DrConfig;
@@ -84,8 +83,8 @@ public void run() {
                   : null);
         }
 
-        createDeleteDrConfigEntryTask(drConfig)
-            .setSubTaskGroupType(SubTaskGroupType.DeleteDrConfig);
+        // When the last xCluster config associated with this DR config is deleted, the dr config
+        // entry will be deleted as well.
 
         if (targetUniverse != null) {
           createMarkUniverseUpdateSuccessTasks(targetUniverse.getUniverseUUID())

managed/src/main/java/com/yugabyte/yw/commissioner/tasks/DestroyUniverse.java

@@ -36,7 +36,6 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
@@ -351,11 +350,11 @@ private void createDeleteXClusterConfigSubtasksAndLockOtherUniverse(
                 false /* keepEntry */,
                 params().isForceDelete,
                 true /* deletePitrConfigs */);
-            if (Objects.nonNull(drConfig) && drConfig.getXClusterConfigs().size() == 1) {
-              createDeleteDrConfigEntryTask(drConfig)
-                  .setSubTaskGroupType(SubTaskGroupType.DeleteDrConfig);
-            }
           });
+
+      // When the last xCluster config associated with this DR config is deleted, the dr config
+      // entry will be deleted as well.
+
       log.debug("Subtasks created to delete these xCluster configs: {}", xClusterConfigs);
     } catch (Exception e) {
       log.error(

managed/src/main/java/com/yugabyte/yw/controllers/DrConfigController.java

@@ -1120,9 +1120,6 @@ public Result failover(UUID customerUUID, UUID drConfigUuid, Http.Request reques
         List<MasterDdlOuterClass.ListTablesResponsePB.TableInfo> targetTableInfoList =
             XClusterConfigTaskBase.getTableInfoList(ybService, targetUniverse);
 
-        List<MasterDdlOuterClass.ListTablesResponsePB.TableInfo> sourceTableInfoList =
-            XClusterConfigTaskBase.getTableInfoList(ybService, sourceUniverse);
-
         // Because during failover, the source universe could be down, we should rely on the target
         // universe to get the table map between source to target.
         Map<String, String> sourceTableIdTargetTableIdMap =

managed/src/main/java/com/yugabyte/yw/models/DrConfig.java

@@ -345,4 +345,17 @@ public XClusterConfigRestartFormData.RestartBootstrapParams getBootstrapBackupPa
   public boolean isHalted() {
     return state == State.Halted;
   }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    DrConfig drConfig = (DrConfig) o;
+    return Objects.equals(uuid, drConfig.uuid);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(uuid);
+  }
 }

managed/src/main/java/com/yugabyte/yw/models/XClusterConfig.java

@@ -1020,6 +1020,16 @@ public void update() {
     super.update();
   }
 
+  @Transactional
+  @Override
+  public boolean delete() {
+    // If the dr config has no other xCluster configs, then delete the dr config as well.
+    if (this.drConfig != null && this.drConfig.getXClusterConfigs().size() == 1) {
+      this.drConfig.delete();
+    }
+    return super.delete();
+  }
+
   public static XClusterConfig getValidConfigOrBadRequest(
       Customer customer, UUID xClusterConfigUUID) {
     XClusterConfig xClusterConfig = getOrBadRequest(xClusterConfigUUID);