When backing up an empty cluster, nothing will be output.

[tongtongyin]

Please answer these questions before submitting your issue. Thanks!!

1. What did you do?
   When backing up an empty cluster, nothing will be output.It will not show that the backup is complete, nor will it show an error.

2. What did you expect to see?
   Similar to a summary ：["Full backup Failed summary: total backup ranges: 0, total success: 0, total failed: 0"] [BackupTS=xxxxxxxxxxxxxxxxxx]

3. What did you see instead?
   Nothing at all

4. What version of BR and TiDB/TiKV/PD are you using?

5. Operation logs
   command：

brlog：

6. Configuration of the cluster and the task

   • tidb-lightning.toml for TiDB-Lightning if possible
   • tikv-importer.toml for TiKV-Importer if possible
   • topology.yml if deployed by TiUP

7. Screenshot/exported-PDF of Grafana dashboard or metrics' graph in Prometheus if possible

[kennytm]

please see #828 about backing up empty database.

[YuJuncen]

Uh, seems the failure summary was putted with log.Info, which record logs to the log file only.

br/pkg/summary/collector.go

Lines 187 to 191 in 31e539c

	if len(tc.failureReasons) != 0 || !tc.successStatus {
	for unitName, reason := range tc.failureReasons {
	logFields = append(logFields, zap.String("unit-name", unitName), zap.Error(reason))
	}
	log.Info(name+" failed summary", logFields...)

Let me fix it... Thanks for reporting this.