Variables initialized before configuration file parsed

[morgo]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

This bug report relates to #9381 -- which is a feature request with a proposed refactor. While we discuss this change, this bug report can be used to workaround the immediate problem:

./bin/tidb-server -P 4001
mysql> show global variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 4000  |
+---------------+-------+
1 row in set (0.02 sec)

2. What did you expect to see?

mysql> show global variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 4001  |
+---------------+-------+
1 row in set (0.02 sec)

3. What did you see instead?

mysql> show global variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 4000  |
+---------------+-------+
1 row in set (0.02 sec)

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?

mysql> select tidb_version()\G
*************************** 1. row ***************************
tidb_version(): Release Version: v3.0.0-beta-92-gf46c558a6-dirty
Git Commit Hash: f46c558a60441e9c79678d1ed946a6cc81765243
Git Branch: accurate-socket-datadir
UTC Build Time: 2019-02-20 03:20:37
GoVersion: go version go1.11.3 linux/amd64
Race Enabled: false
TiKV Min Version: 2.1.0-alpha.1-ff3dd160846b7d1aed9079c389fc188f7f5ea13e
Check Table Before Drop: false
1 row in set (0.00 sec)

[jackysp]

I think it is not easy to control the init function, we could overwrite the sys vars at https://github.com/pingcap/tidb/blob/master/tidb-server/main.go#L453

[morgo]

Thanks! This issue now has a workaround, closing.