cluster_info table: it's better to show v4.0.0-rc instead of 5.7.25-TiDB-v4.0.0-rc

[zz-jason]

Description

start a cluster, then show the cluster info:

select * from information_schema.cluster_info;

the result is:

mysql> select * from information_schema.cluster_info;
+------+-----------------+-----------------+-----------------------+------------------------------------------+---------------------------+------------------+
| TYPE | INSTANCE        | STATUS_ADDRESS  | VERSION               | GIT_HASH                                 | START_TIME                | UPTIME           |
+------+-----------------+-----------------+-----------------------+------------------------------------------+---------------------------+------------------+
| tidb | 127.0.0.1:4000  | 127.0.0.1:10080 | 5.7.25-TiDB-v4.0.0-rc | 79db9e30ab8f98ac07c8ae55c66dfecc24b43d56 | 2020-04-11T02:10:17-04:00 | 12m11.024353044s |
| pd   | 127.0.0.1:2379  | 127.0.0.1:2379  | 4.0.0-rc              | 6f06805f3b0070107fcb4af68b2fc224dee0714d | 2020-04-11T02:10:11-04:00 | 12m17.024356408s |
| tikv | 127.0.0.1:20160 | 127.0.0.1:20180 | 4.0.0-rc              | f45d0c963df3ee4b1011caf5eb146cacd1fbbad8 | 2020-04-11T02:10:15-04:00 | 12m13.02435805s  |
+------+-----------------+-----------------+-----------------------+------------------------------------------+---------------------------+------------------+
3 rows in set (0.00 sec)

As you can see, VERSION of tidb is different from tikv and pd. I think it's better to show the same version info.

[zz-jason]

@crazycs520 PTAL

[crazycs520]

Already fix in #16003

[dveeden]

This is fixed here:

tidb/infoschema/tables.go

Lines 1762 to 1784 in 967699a

	// FormatTiDBVersion make TiDBVersion consistent to TiKV and PD.
	// The default TiDBVersion is 5.7.25-TiDB-${TiDBReleaseVersion}.
	func FormatTiDBVersion(TiDBVersion string, isDefaultVersion bool) string {
	var version, nodeVersion string
	// The user hasn't set the config 'ServerVersion'.
	if isDefaultVersion {
	nodeVersion = TiDBVersion[strings.Index(TiDBVersion, "TiDB-")+len("TiDB-"):]
	if len(nodeVersion) > 0 && nodeVersion[0] == 'v' {
	nodeVersion = nodeVersion[1:]
	}
	nodeVersions := strings.Split(nodeVersion, "-")
	if len(nodeVersions) == 1 {
	version = nodeVersions[0]
	} else if len(nodeVersions) >= 2 {
	version = fmt.Sprintf("%s-%s", nodeVersions[0], nodeVersions[1])
	}
	} else { // The user has already set the config 'ServerVersion',it would be a complex scene, so just use the 'ServerVersion' as version.
	version = TiDBVersion
	}
	return version
	}