[BACKPORT 2024.1][#13358] YSQL: YBDdlAtomicityBackupTest::RunDdlAtomi…

…cityTest test change

Summary:
The way the test YBDdlAtomicityBackupTest::RunDdlAtomicityTest is written, all
the DDLs will be inflight during the backup - so backup will fail. It's better
to test the case where backup fails if any single DDL is inflight. This diff
changes the test to randomly pick one DDL to be inflight and verify the backup
fails.
Jira: DB-2996

Original commit: 5ebfef8 / D35140

Test Plan: ./yb_build.sh release --cxx-test yb-backup-cross-feature-test --gtest_filter YBDdlAtomicityBackupTest.DdlRollbackAtomicityTest  -n 20

Reviewers: fizaa

Reviewed By: fizaa

Subscribers: yql, ybase

Tags: #jenkins-ready

Differential Revision: https://phorge.dev.yugabyte.com/D35150

src/yb/tools/yb-backup/yb-backup-cross-feature-test.cc

@@ -1739,12 +1739,13 @@ Status YBDdlAtomicityBackupTest::RunDdlAtomicityTest(pgwrapper::DdlErrorInjectio
 
   auto client = VERIFY_RESULT(cluster_->CreateClient());
 
-  // Run all DDLs after pausing DDL rollback.
   RETURN_NOT_OK(cluster_->SetFlagOnMasters("TEST_pause_ddl_rollback", "true"));
 
   if (inject_error) {
-    RETURN_NOT_OK(RunAllDdlsWithErrorInjection(&conn));
+    // Run one failed DDL after pausing DDL rollback.
+    RETURN_NOT_OK(RunOneDdlWithErrorInjection(&conn));
   } else {
+    // Run all DDLs after pausing DDL rollback.
     RETURN_NOT_OK(RunAllDdls(&conn));
   }
 

src/yb/yql/pgwrapper/pg_ddl_atomicity_test_base.cc

@@ -90,6 +90,15 @@ Status PgDdlAtomicityTestBase::RunAllDdlsWithErrorInjection(PGConn* conn) {
   return Status::OK();
 }
 
+Status PgDdlAtomicityTestBase::RunOneDdlWithErrorInjection(PGConn* conn) {
+  const auto& ddls = GetAllDDLs();
+  const auto selected = RandomUniformInt(0UL, ddls.size() - 1);
+  const auto& ddl = ddls[selected];
+  LOG(INFO) << "selected ddl to fail: " << ddl;
+  RETURN_NOT_OK(conn->TestFailDdl(ddl));
+  return Status::OK();
+}
+
 Status PgDdlAtomicityTestBase::VerifyAllSuccessfulDdls(PGConn *conn,
                                                        client::YBClient* client,
                                                        const string& database) {

src/yb/yql/pgwrapper/pg_ddl_atomicity_test_base.h

@@ -135,6 +135,10 @@ class PgDdlAtomicityTestBase : public LibPqTestBase {
   // initiate rollback on the YB-Master.
   Status RunAllDdlsWithErrorInjection(PGConn* conn);
 
+  // From all possible DDLs supported by this test, randomly select one DDL and run with
+  // error injection. The selected DDL will fail and initiate rollback on the YB-Master.
+  Status RunOneDdlWithErrorInjection(PGConn* conn);
+
   // API that can be used after 'RunAllDdls' above to wait for all the DDL verification to
   // complete.
   Status WaitForDdlVerificationAfterSuccessfulDdl(