use background context to restart mysqld after backup. fix and add lo…

…gging

Signed-off-by: deepthi <deepthi@planetscale.com>

go/vt/mysqlctl/builtinbackupengine.go

@@ -301,8 +301,8 @@ func (be *BuiltinBackupEngine) ExecuteBackup(ctx context.Context, cnf *Mycnf, my
 	backupErr := be.backupFiles(ctx, cnf, mysqld, logger, bh, replicationPosition, backupConcurrency, hookExtraEnv)
 	usable := backupErr == nil
 
-	// Try to restart mysqld
-	err = mysqld.Start(ctx, cnf)
+	// Try to restart mysqld, use background context in case we timed out the original context
+	err = mysqld.Start(context.Background(), cnf)
 	if err != nil {
 		return usable, vterrors.Wrap(err, "can't restart mysqld")
 	}
@@ -420,21 +420,22 @@ func (be *BuiltinBackupEngine) backupFile(ctx context.Context, cnf *Mycnf, mysql
 		return err
 	}
 
+	logger.Infof("Backing up file: %v", fe.Name)
 	// Open the destination file for writing, and a buffer.
 	wc, err := bh.AddFile(ctx, name, fi.Size())
 	if err != nil {
-		return vterrors.Wrapf(err, "cannot add file: %v", name)
+		return vterrors.Wrapf(err, "cannot add file: %v,%v", name, fe.Name)
 	}
-	defer func() {
+	defer func(name, fileName string) {
 		if rerr := wc.Close(); rerr != nil {
 			if err != nil {
 				// We already have an error, just log this one.
-				logger.Errorf2(rerr, "failed to close file %v", name)
+				logger.Errorf2(rerr, "failed to close file %v,%v", name, fe.Name)
 			} else {
 				err = rerr
 			}
 		}
-	}()
+	}(name, fe.Name)
 	dst := bufio.NewWriterSize(wc, writerBufferSize)
 
 	// Create the hasher and the tee on top.

go/vt/vttablet/tabletmanager/rpc_backup.go

@@ -84,8 +84,14 @@ func (agent *ActionAgent) Backup(ctx context.Context, concurrency int, logger lo
 	returnErr := mysqlctl.Backup(ctx, agent.Cnf, agent.MysqlDaemon, l, dir, name, concurrency, agent.hookExtraEnv())
 
 	if builtin != nil {
+
+		bgCtx := context.Background()
+		// Starting from here we won't be able to recover if we get stopped by a cancelled
+		// context. It is also possible that the context already timed out during the
+		// above call to Backup. Thus we use the background context to get through to the finish.
+
 		// change our type back to the original value
-		_, err = topotools.ChangeType(ctx, agent.TopoServer, tablet.Alias, originalType)
+		_, err = topotools.ChangeType(bgCtx, agent.TopoServer, tablet.Alias, originalType)
 		if err != nil {
 			// failure in changing the topology type is probably worse,
 			// so returning that (we logged the snapshot error anyway)
@@ -96,7 +102,7 @@ func (agent *ActionAgent) Backup(ctx context.Context, concurrency int, logger lo
 		}
 
 		// let's update our internal state (start query service and other things)
-		if err := agent.refreshTablet(ctx, "after backup"); err != nil {
+		if err := agent.refreshTablet(bgCtx, "after backup"); err != nil {
 			return err
 		}
 	}