infoschema: add current txn start time in processlist table

[lysu]

What problem does this PR solve?

help identify long-running transaction(maybe client forgot to commit/rollback) add TxnStart column to information_schema.processlist

mysql> select * from information_schema.processlist;
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------+
| ID   | USER | HOST      | DB   | COMMAND | TIME | STATE | INFO                                         | MEM  | TxnStart |
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------+
|    1 | root | 127.0.0.1 | test | Query   |    0 | 2     | select * from information_schema.processlist |    0 |          |
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------+
1 row in set (0.00 sec)

mysql> begin;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from information_schema.processlist;
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------------------------------------+
| ID   | USER | HOST      | DB   | COMMAND | TIME | STATE | INFO                                         | MEM  | TxnStart                               |
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------------------------------------+
|    1 | root | 127.0.0.1 | test | Query   |    0 | 3     | select * from information_schema.processlist |    0 | 07-29 12:34:29.166(410091485702651904) |
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------------------------------------+
1 row in set (0.00 sec)

mysql> commit;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from information_schema.processlist;
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------+
| ID   | USER | HOST      | DB   | COMMAND | TIME | STATE | INFO                                         | MEM  | TxnStart |
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------+
|    1 | root | 127.0.0.1 | test | Query   |    0 | 2     | select * from information_schema.processlist |    0 |          |
+------+------+-----------+------+---------+------+-------+----------------------------------------------+------+----------+
1 row in set (0.00 sec)

What is changed and how it works?

add a column to info schema table, but didn't change show proceslist to keep compatibility.

Check List

Tests

• Unit test
• Integration test

Code changes

• add new column to infoschema

Side effects

• N/A

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation

---

This change is 

[lysu]

/run-all-tests

[jackysp]

LGTM

[jackysp]

The CI failed, seems we need to consider the time zone.

... obtained string = "" +
...     "[1 user-1 localhost information_schema Quit 9223372036 1 <nil> 0 ]\n" +
...     "[2 user-2 localhost <nil> Init DB 9223372036 2 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 0 07-29 03:26:05.158(410090409861578752)]\n"
... expected string = "" +
...     "[1 user-1 localhost information_schema Quit 9223372036 1 <nil> 0 ]\n" +
...     "[2 user-2 localhost <nil> Init DB 9223372036 2 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 0 07-29 11:26:05.158(410090409861578752)]\n"

[codecov]

Codecov Report

Merging #11491 into master will increase coverage by 0.0201%.
The diff coverage is 100%.

@@               Coverage Diff               @@
##             master    #11491        +/-   ##
===============================================
+ Coverage   81.3308%   81.351%   +0.0201%     
===============================================
  Files           424       424                
  Lines         91247     90922       -325     
===============================================
- Hits          74212     73966       -246     
+ Misses        11710     11635        -75     
+ Partials       5325      5321         -4

[lysu]

/run-all-tests

@jackysp PTAL

[XuHuaiyu]

LGTM

[jackysp]

LGTM

[sre-bot]

cherry pick to release-3.0 failed

[sre-bot]

It seems that, not for sure, we failed to cherry-pick this commit to release-3.0. Please comment '/run-cherry-picker' to try to trigger the cherry-picker if we did fail to cherry-pick this commit before. @lysu PTAL.

[lysu]

/run-cherry-picker

[sre-bot]

cherry pick to release-3.0 in PR #16160