release-20.2: backupccl: only restore system tables included in backup

pkg/ccl/backupccl/full_cluster_backup_restore_test.go

@@ -186,6 +186,10 @@ CREATE TABLE data2.foo (a int);
 				// createdAt and statisticsID are re-generated on RESTORE.
 				query := fmt.Sprintf("SELECT \"tableID\", name, \"columnIDs\", \"rowCount\" FROM system.table_statistics")
 				verificationQueries[i] = query
+			case systemschema.SettingsTable.Name:
+				// We don't include the cluster version.
+				query := fmt.Sprintf("SELECT * FROM system.%s WHERE name <> 'version'", table)
+				verificationQueries[i] = query
 			default:
 				query := fmt.Sprintf("SELECT * FROM system.%s", table)
 				verificationQueries[i] = query

pkg/ccl/backupccl/restore_job.go

@@ -798,6 +798,17 @@ func isDatabaseEmpty(
 	return true, nil
 }
 
+func getTempSystemDBID(details jobspb.RestoreDetails) descpb.ID {
+	tempSystemDBID := keys.MinNonPredefinedUserDescID
+	for id := range details.DescriptorRewrites {
+		if int(id) > tempSystemDBID {
+			tempSystemDBID = int(id)
+		}
+	}
+
+	return descpb.ID(tempSystemDBID)
+}
+
 // createImportingDescriptors create the tables that we will restore into. It also
 // fetches the information from the old tables that we need for the restore.
 func createImportingDescriptors(
@@ -837,15 +848,11 @@ func createImportingDescriptors(
 			types = append(types, mut)
 		}
 	}
-	tempSystemDBID := keys.MinNonPredefinedUserDescID
-	for id := range details.DescriptorRewrites {
-		if int(id) > tempSystemDBID {
-			tempSystemDBID = int(id)
-		}
-	}
+
 	if details.DescriptorCoverage == tree.AllDescriptors {
-		databases = append(databases, dbdesc.NewInitial(
-			descpb.ID(tempSystemDBID), restoreTempSystemDB, security.AdminRole))
+		tempSystemDBID := getTempSystemDBID(details)
+		databases = append(databases, dbdesc.NewInitial(tempSystemDBID, restoreTempSystemDB,
+			security.AdminRole))
 	}
 
 	// We get the spans of the restoring tables _as they appear in the backup_,
@@ -1199,7 +1206,7 @@ func (r *restoreResumer) Resume(
 	// restores were a special case, but really we should be making only the
 	// temporary system tables public before we restore all the system table data.
 	if details.DescriptorCoverage == tree.AllDescriptors {
-		if err := r.restoreSystemTables(ctx, p.ExecCfg().DB); err != nil {
+		if err := r.restoreSystemTables(ctx, p.ExecCfg().DB, details, tables); err != nil {
 			return err
 		}
 	}
@@ -1768,25 +1775,57 @@ func getRestoringPrivileges(
 
 // restoreSystemTables atomically replaces the contents of the system tables
 // with the data from the restored system tables.
-func (r *restoreResumer) restoreSystemTables(ctx context.Context, db *kv.DB) error {
+func (r *restoreResumer) restoreSystemTables(
+	ctx context.Context,
+	db *kv.DB,
+	restoreDetails jobspb.RestoreDetails,
+	tables []catalog.TableDescriptor,
+) error {
+	tempSystemDBID := getTempSystemDBID(restoreDetails)
+
 	executor := r.execCfg.InternalExecutor
 	var err error
-	for _, systemTable := range fullClusterSystemTables {
+
+	// Iterate through all the tables that we're restoring, and if it was restored
+	// to the temporary system DB then copy it's data over to the real system
+	// table.
+	for _, table := range tables {
+		if table.GetParentID() != tempSystemDBID {
+			continue
+		}
+		systemTableName := table.GetName()
+
 		if err := db.Txn(ctx, func(ctx context.Context, txn *kv.Txn) error {
 			txn.SetDebugName("system-restore-txn")
-			stmtDebugName := fmt.Sprintf("restore-system-systemTable-%s", systemTable)
+			stmtDebugName := fmt.Sprintf("restore-system-systemTable-%s", systemTableName)
 			// Don't clear the jobs table as to not delete the jobs that are performing
 			// the restore.
-			if systemTable != systemschema.JobsTable.Name {
-				deleteQuery := fmt.Sprintf("DELETE FROM system.%s WHERE true;", systemTable)
+			if systemTableName == systemschema.SettingsTable.Name {
+				// Don't delete the cluster version.
+				deleteQuery := fmt.Sprintf("DELETE FROM system.%s WHERE name <> 'version';", systemTableName)
 				_, err = executor.Exec(ctx, stmtDebugName+"-data-deletion", txn, deleteQuery)
 				if err != nil {
-					return errors.Wrapf(err, "deleting data from system.%s", systemTable)
+					return errors.Wrapf(err, "deleting data from system.%s", systemTableName)
 				}
+			} else if systemTableName != systemschema.JobsTable.Name {
+				// Don't clear the jobs table as to not delete the jobs that are
+				// performing the restore.
+				deleteQuery := fmt.Sprintf("DELETE FROM system.%s WHERE true;", systemTableName)
+				_, err = executor.Exec(ctx, stmtDebugName+"-data-deletion", txn, deleteQuery)
+				if err != nil {
+					return errors.Wrapf(err, "deleting data from system.%s", systemTableName)
+				}
+			}
+
+			restoreQuery := fmt.Sprintf("INSERT INTO system.%s (SELECT * FROM %s.%s);", systemTableName,
+				restoreTempSystemDB, systemTableName)
+			if systemTableName == systemschema.SettingsTable.Name {
+				// Don't overwrite the cluster version.
+				restoreQuery = fmt.Sprintf("INSERT INTO system.%s (SELECT * FROM %s.%s WHERE name <> 'version');",
+					systemTableName, restoreTempSystemDB, systemTableName)
 			}
-			restoreQuery := fmt.Sprintf("INSERT INTO system.%s (SELECT * FROM %s.%s);", systemTable, restoreTempSystemDB, systemTable)
 			if _, err := executor.Exec(ctx, stmtDebugName+"-data-insert", txn, restoreQuery); err != nil {
-				return errors.Wrapf(err, "inserting data to system.%s", systemTable)
+				return errors.Wrapf(err, "inserting data to system.%s", systemTableName)
 			}
 			return nil
 		}); err != nil {

pkg/ccl/backupccl/restore_old_versions_test.go

@@ -9,12 +9,16 @@
 package backupccl
 
 import (
+	"context"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
 
 	"github.com/cockroachdb/cockroach/pkg/base"
+	"github.com/cockroachdb/cockroach/pkg/testutils"
+	"github.com/cockroachdb/cockroach/pkg/testutils/sqlutils"
+	"github.com/cockroachdb/cockroach/pkg/testutils/testcluster"
 	"github.com/cockroachdb/cockroach/pkg/util/leaktest"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/stretchr/testify/require"
@@ -46,15 +50,30 @@ func TestRestoreOldVersions(t *testing.T) {
 	const (
 		testdataBase = "testdata/restore_old_versions"
 		exportDirs   = testdataBase + "/exports"
+		clusterDirs  = testdataBase + "/cluster"
 	)
-	dirs, err := ioutil.ReadDir(exportDirs)
-	require.NoError(t, err)
-	for _, dir := range dirs {
-		require.True(t, dir.IsDir())
-		exportDir, err := filepath.Abs(filepath.Join(exportDirs, dir.Name()))
+
+	t.Run("table-restore", func(t *testing.T) {
+		dirs, err := ioutil.ReadDir(exportDirs)
 		require.NoError(t, err)
-		t.Run(dir.Name(), restoreOldVersionTest(exportDir))
-	}
+		for _, dir := range dirs {
+			require.True(t, dir.IsDir())
+			exportDir, err := filepath.Abs(filepath.Join(exportDirs, dir.Name()))
+			require.NoError(t, err)
+			t.Run(dir.Name(), restoreOldVersionTest(exportDir))
+		}
+	})
+
+	t.Run("cluster-restore", func(t *testing.T) {
+		dirs, err := ioutil.ReadDir(clusterDirs)
+		require.NoError(t, err)
+		for _, dir := range dirs {
+			require.True(t, dir.IsDir())
+			exportDir, err := filepath.Abs(filepath.Join(clusterDirs, dir.Name()))
+			require.NoError(t, err)
+			t.Run(dir.Name(), restoreOldVersionClusterTest(exportDir))
+		}
+	})
 }
 
 func restoreOldVersionTest(exportDir string) func(t *testing.T) {
@@ -86,3 +105,36 @@ func restoreOldVersionTest(exportDir string) func(t *testing.T) {
 		sqlDB.CheckQueryResults(t, `SELECT * FROM test.t4 ORDER BY k`, results)
 	}
 }
+
+func restoreOldVersionClusterTest(exportDir string) func(t *testing.T) {
+	return func(t *testing.T) {
+		externalDir, dirCleanup := testutils.TempDir(t)
+		ctx := context.Background()
+		tc := testcluster.StartTestCluster(t, singleNode, base.TestClusterArgs{
+			ServerArgs: base.TestServerArgs{
+				ExternalIODir: externalDir,
+			},
+		})
+		sqlDB := sqlutils.MakeSQLRunner(tc.Conns[0])
+		defer func() {
+			tc.Stopper().Stop(ctx)
+			dirCleanup()
+		}()
+		err := os.Symlink(exportDir, filepath.Join(externalDir, "foo"))
+		require.NoError(t, err)
+
+		// Ensure that the restore succeeds.
+		sqlDB.Exec(t, `RESTORE FROM $1`, LocalFoo)
+
+		sqlDB.CheckQueryResults(t, "SHOW USERS", [][]string{
+			{"admin", "", "{}"},
+			{"craig", "", "{}"},
+			{"root", "", "{admin}"},
+		})
+		sqlDB.CheckQueryResults(t, "SELECT * FROM system.comments", [][]string{
+			{"0", "52", "0", "database comment string"},
+			{"1", "53", "0", "table comment string"},
+		})
+		sqlDB.CheckQueryResults(t, "SELECT * FROM data.bank", [][]string{{"1"}})
+	}
+}

pkg/ccl/backupccl/testdata/restore_old_versions/create_cluster.sql

@@ -0,0 +1,11 @@
+CREATE USER craig;
+CREATE DATABASE data;
+CREATE TABLE data.bank (a INT);
+INSERT INTO TABLE data.bank VALUES (1);
+
+COMMENT ON TABLE data.bank IS 'table comment string';
+COMMENT ON DATABASE data IS 'database comment string';
+
+INSERT INTO system.locations ("localityKey", "localityValue", latitude, longitude) VALUES ('city', 'nyc', 10, 10);
+
+ALTER TABLE data.bank CONFIGURE ZONE USING gc.ttlseconds = 3600;