Use only one table to operate - status table

Author: AMecea

pkg/controller/mysqlcluster/internal/syncer/statefullset.go

@@ -281,7 +281,9 @@ func (s *sfsSyncer) ensureContainersSpec() []core.Container {
 				"mysql",
 				fmt.Sprintf("--defaults-file=%s", confClientPath),
 				"-e",
-				fmt.Sprintf("SELECT * FROM %s.%s", constants.OperatorDbName, constants.OperatorReadinessTableName),
+				// nolint: gosec
+				fmt.Sprintf("SELECT * FROM %s.%s WHERE name='configured' AND value='1'",
+					constants.OperatorDbName, constants.OperatorStatusTableName),
 			},
 		},
 	})

pkg/controller/node/sql.go

@@ -125,14 +125,9 @@ func (r *nodeSQLRunner) ChangeMasterTo(ctx context.Context, masterHost, user, pa
 
 // MarkConfigurationDone write in a MEMORY table value. The readiness probe checks for that value to exist to succeed.
 func (r *nodeSQLRunner) MarkConfigurationDone(ctx context.Context) error {
-	query := `
-    CREATE TABLE IF NOT EXISTS %s.%s (
-		ok tinyint(1) NOT NULL
-    ) ENGINE=MEMORY;
-
-    INSERT INTO %[1]s.%[2]s VALUES (1);
-    `
-	query = fmt.Sprintf(query, constants.OperatorDbName, constants.OperatorReadinessTableName)
+	// nolint: gosec
+	query := fmt.Sprintf("REPLACE INTO %s.%s VALUES ('%s', '1');",
+		constants.OperatorDbName, constants.OperatorStatusTableName, "configured")
 
 	if err := r.runQuery(ctx, query); err != nil {
 		return fmt.Errorf("failed to mark configuration done, err: %s", err)
@@ -203,38 +198,35 @@ func (r *nodeSQLRunner) dbConn() (*sql.DB, func(), error) {
 }
 
 func (r *nodeSQLRunner) SetPurgedGTID(ctx context.Context) error {
-	// first check if the GTID should be set, if the table exists or if the GTID was set before (used)
+	// first check if the GTID should be set, if in the status table is a key with the GTID that was set
 	// nolint: gosec
-	qq := fmt.Sprintf("SELECT used FROM %[1]s.%[2]s WHERE id=1",
-		constants.OperatorDbName, constants.OperatorGtidsTableName)
-
-	var used bool
-	if err := r.readFromMysql(ctx, qq, &used); err != nil {
-		// if it's a: "Table doesn't exist" error then GTID should not be set, it's a master case.
-		if isMySQLError(err, 1146) || err == sql.ErrNoRows {
-			log.V(1).Info("GTID purged table does not exists", "host", r.Host())
-			return nil
+	qq := fmt.Sprintf("SELECT value FROM %s.%s WHERE name='%s'",
+		constants.OperatorDbName, constants.OperatorStatusTableName, "set_gtid_purged")
+
+	var value string
+	if err := r.readFromMysql(ctx, qq, &value); err != nil {
+		// if no rows found then continue to add GTID purged
+		if err != sql.ErrNoRows {
+			return err
 		}
-
-		return err
 	}
 
-	if used {
-		log.V(1).Info("GTID purged set", "host", r.Host())
+	if len(value) != 0 {
+		log.V(1).Info("GTID purged was already set", "host", r.Host(), "gtid_purged", value)
 		return nil
 	}
 
 	// GTID exists and should be set in a transaction
 	// nolint: gosec
 	query := fmt.Sprintf(`
-      SET @@SESSION.SQL_LOG_BIN = 0;
-      START TRANSACTION;
-        SELECT gtid INTO @gtid FROM %[1]s.%[2]s WHERE id=1 AND used=false;
-	    RESET MASTER;
-	    SET @@GLOBAL.GTID_PURGED = @gtid;
-	    REPLACE INTO %[1]s.%[2]s VALUES (1, @gtid, true);
-      COMMIT;
-    `, constants.OperatorDbName, constants.OperatorGtidsTableName)
+	  SET @@SESSION.SQL_LOG_BIN = 0;
+	  START TRANSACTION;
+		SELECT value INTO @gtid FROM %[1]s.%[2]s WHERE name='%s';
+		RESET MASTER;
+		SET @@GLOBAL.GTID_PURGED = @gtid;
+		REPLACE INTO %[1]s.%[2]s VALUES ('%s', @gtid);
+	  COMMIT;
+    `, constants.OperatorDbName, constants.OperatorStatusTableName, "backup_gtid_purged", "set_gtid_purged")
 
 	if err := r.runQuery(ctx, query); err != nil {
 		return err

pkg/sidecar/appconf.go

@@ -179,19 +179,24 @@ func initFileQuery(cfg *Config, gtidPurged string) []byte {
 		[]string{"CREATE", "SELECT", "DELETE", "UPDATE", "INSERT"}, fmt.Sprintf("%s.%s", toolsDbName, toolsHeartbeatTableName),
 		[]string{"REPLICATION CLIENT"}, "*.*")...)
 
-	if len(gtidPurged) != 0 {
-		// If the xtrabackup information has GTID_PURGED then insert it into a table
-		// nolint: gosec
-		queries = append(queries, fmt.Sprintf(`
+	// create the status table used by the operator to configure or to mask MySQL node ready
+	// nolint: gosec
+	queries = append(queries, fmt.Sprintf(`
 		CREATE TABLE IF NOT EXISTS %[1]s.%[2]s (
-            id int PRIMARY KEY,
-            gtid varchar(512) NOT NULL,
-            used BOOLEAN DEFAULT false
-		)`, constants.OperatorDbName, constants.OperatorGtidsTableName))
+            name varchar(64) PRIMARY KEY,
+            value varchar(512) NOT NULL
+		)`, constants.OperatorDbName, constants.OperatorStatusTableName))
 
+	// mark node as not configured at startup, the operator will mark it configured
+	// nolint: gosec
+	queries = append(queries, fmt.Sprintf("REPLACE INTO %s.%s VALUES ('%s', '0')",
+		constants.OperatorDbName, constants.OperatorStatusTableName, "configured"))
+
+	if len(gtidPurged) != 0 {
+		// if gtid is found in the backup then set it in the status table to be processed by the operator
 		// nolint: gosec
-		queries = append(queries, fmt.Sprintf(`REPLACE INTO %s.%s (id, gtid) VALUES (1, '%s')`,
-			constants.OperatorDbName, constants.OperatorGtidsTableName, gtidPurged))
+		queries = append(queries, fmt.Sprintf(`REPLACE INTO %s.%s VALUES ('%s', '%s')`,
+			constants.OperatorDbName, constants.OperatorStatusTableName, "backup_gtid_purged", gtidPurged))
 	}
 
 	return []byte(strings.Join(queries, ";\n") + ";\n")

pkg/sidecar/server.go

@@ -90,7 +90,7 @@ func (s *server) backupHandler(w http.ResponseWriter, r *http.Request) {
 
 	// nolint: gosec
 	xtrabackup := exec.Command("xtrabackup", "--backup", "--slave-info", "--stream=xbstream",
-		fmt.Sprintf("--tables-exclude=%s.%s", constants.OperatorDbName, constants.OperatorGtidsTableName),
+		fmt.Sprintf("--tables-exclude=%s.%s", constants.OperatorDbName, constants.OperatorStatusTableName),
 		"--host=127.0.0.1", fmt.Sprintf("--user=%s", s.cfg.ReplicationUser),
 		fmt.Sprintf("--password=%s", s.cfg.ReplicationPassword),
 		"--target-dir=/tmp/xtrabackup_backupfiles/")

pkg/util/constants/constants.go

@@ -41,11 +41,9 @@ const (
 	// SlaveLagQuery in hack/charts/mysql-operator/values.yaml.
 	OperatorDbName = "sys_operator"
 
-	// OperatorGtidsTableName represents the name of the table that is used to store the GTID
-	OperatorGtidsTableName = "gtids"
-
-	// OperatorReadinessTableName is the name of the table that is used to store a readiness flag (boolean)
-	OperatorReadinessTableName = "readiness"
+	// OperatorStatusTableName represents the name of the table that contains information about MySQL status, like:
+	// if mysql is configure by the operator, if PURGE_GTID is set or not, etc
+	OperatorStatusTableName = "status"
 
 	// ConfVolumeMountPath is the path where mysql configs will be mounted
 	ConfVolumeMountPath = "/etc/mysql"