[#25237] YSQL: PG15 upgrade: Block Create DB during major upgrade

Summary:
Block the creation of new databases during for the entire ysql major upgrade process.
Prior to this change the CreateNamespace call would only fail during the ysql major catalog upgrade phase, but the CREATE DATABASE SQL statement would fail trying to modify the system catalog tables. This happens because the ysql major catalog upgrade is just one of the steps in the upgrade, and we block the catalog for the entire upgrade. Since CREATE DATABASE is not yet an atomic DDL, this skips the cleanup of the partially created keyspace and cause further creation attempts of the same database to fail.

- Unified the error message for all the DDLs that are blocked during the major upgrade.
- Removed `VerifyDroppedColumnsForUpgrade` since it is never invoked. `CatalogManager::AlterTable` is completely skipped during the upgrade.
- Removed some duplicate checks from `CatalogManager::DeleteYsqlDatabase` since its caller `CatalogManager::DoDeleteNamespace` performs the exact same checks already.

Fixes #25237
Jira: DB-14425

Test Plan: YsqlMajorUpgradeDdlBlockingTest.CreateAndDropDBs

Reviewers: telgersma, smishra

Reviewed By: telgersma

Subscribers: yql, ybase

Differential Revision: https://phorge.dev.yugabyte.com/D41330

src/yb/integration-tests/upgrade-tests/ysql_major_upgrade_ddl_blocking-test.cc

@@ -226,10 +226,9 @@ TEST_F(YsqlMajorUpgradeDdlBlockingTest, CreateAndDropDBs) {
   ASSERT_OK(RestartAllMastersInCurrentVersion(kNoDelayBetweenNodes));
 
   auto validate_db_ddls_fail = [this] {
-    // TODO: Enable after CreateDatabase blocking is properly implemented.
-    // ASSERT_NOK_STR_CONTAINS(
-    //     ExecuteStatement("CREATE DATABASE new_db2"),
-    //     "No new namespaces can be created during a major YSQL upgrade");
+    ASSERT_NOK_STR_CONTAINS(
+        ExecuteStatement("CREATE DATABASE new_db2"),
+        "No new namespaces can be created during a major YSQL upgrade");
     ASSERT_NOK_STR_CONTAINS(ExecuteStatement("DROP DATABASE new_db1"), kExpectedDdlError);
   };
 

src/yb/master/catalog_manager.h

@@ -2923,8 +2923,6 @@ class CatalogManager : public CatalogManagerIf, public SnapshotCoordinatorContex
       bool is_colocated_via_database, const NamespaceId& namespace_id,
       const NamespaceName& namespace_name, const TableInfoPtr& indexed_table) REQUIRES(mutex_);
 
-  bool IsYsqlMajorCatalogUpgradeInProgress() const;
-
   bool SkipCatalogVersionChecks() override;
 
   // Should be bumped up when tablet locations are changed.

src/yb/master/ysql/ysql_initdb_major_upgrade_handler.cc

@@ -175,10 +175,6 @@ Status YsqlInitDBAndMajorUpgradeHandler::RollbackYsqlMajorCatalogVersion(const L
   return sync.Wait();
 }
 
-bool YsqlInitDBAndMajorUpgradeHandler::IsYsqlMajorCatalogUpgradeInProgress() const {
-  return !IsYsqlMajorCatalogUpgradeDone().done();
-}
-
 Result<YsqlMajorCatalogUpgradeState>
 YsqlInitDBAndMajorUpgradeHandler::GetYsqlMajorCatalogUpgradeState() const {
   const auto state = ysql_catalog_config_.GetMajorCatalogUpgradeState();
@@ -207,7 +203,7 @@ YsqlInitDBAndMajorUpgradeHandler::GetYsqlMajorCatalogUpgradeState() const {
 bool YsqlInitDBAndMajorUpgradeHandler::IsWriteToCatalogTableAllowed(
     const TableId& table_id, bool is_forced_update) const {
   // During the upgrade only allow special updates to the catalog.
-  if (IsYsqlMajorUpgradeInProgress()) {
+  if (IsMajorUpgradeInProgress()) {
     return is_forced_update;
   }
 

src/yb/master/ysql/ysql_initdb_major_upgrade_handler.h

@@ -62,9 +62,7 @@ class YsqlInitDBAndMajorUpgradeHandler {
   // The upgrade is considered to have started when the yb-master leader has upgraded to a new major
   // catalog version.
   // The upgrade is completed after it has been finalized.
-  bool IsYsqlMajorUpgradeInProgress() const { return ysql_major_upgrade_in_progress_; }
-
-  bool IsYsqlMajorCatalogUpgradeInProgress() const;
+  bool IsMajorUpgradeInProgress() const { return ysql_major_upgrade_in_progress_; }
 
   Result<YsqlMajorCatalogUpgradeState> GetYsqlMajorCatalogUpgradeState() const;
 

src/yb/master/ysql/ysql_manager.cc

@@ -106,8 +106,8 @@ Status YsqlManager::SetInitDbDone(const LeaderEpoch& epoch) {
   return ysql_catalog_config_.SetInitDbDone(Status::OK(), epoch);
 }
 
-bool YsqlManager::IsYsqlMajorCatalogUpgradeInProgress() const {
-  return ysql_initdb_and_major_upgrade_helper_->IsYsqlMajorCatalogUpgradeInProgress();
+bool YsqlManager::IsMajorUpgradeInProgress() const {
+  return ysql_initdb_and_major_upgrade_helper_->IsMajorUpgradeInProgress();
 }
 
 uint64_t YsqlManager::GetYsqlCatalogVersion() const { return ysql_catalog_config_.GetVersion(); }
@@ -155,7 +155,7 @@ Result<TableId> YsqlManager::GetVersionSpecificCatalogTableId(
 
   // Use the current version of the catalog if it is updatable, since if the current version is
   // available in the MONITORING phase, it can be deleted by a Rollback.
-  if (!ysql_initdb_and_major_upgrade_helper_->IsYsqlMajorUpgradeInProgress()) {
+  if (!IsMajorUpgradeInProgress()) {
     return current_table_id;
   }
 

src/yb/master/ysql/ysql_manager.h

@@ -57,7 +57,7 @@ class YsqlManager : public YsqlManagerIf {
 
   Status SetInitDbDone(const LeaderEpoch& epoch);
 
-  bool IsYsqlMajorCatalogUpgradeInProgress() const;
+  bool IsMajorUpgradeInProgress() const;
 
   void HandleNewTableId(const TableId& table_id);