*: fix the Host column of 'show processlist'

[wshwsh12]

What problem does this PR solve?

#10903
The Host column should be host_name:client_port format.

What is changed and how it works?

open 2 mysql client and run show processlist; both.
Before this pr:

mysql> show processlist;
+------+------+-----------+------+---------+------+-------+------------------+
| Id   | User | Host      | db   | Command | Time | State | Info             |
+------+------+-----------+------+---------+------+-------+------------------+
|    1 | root | 127.0.0.1 | NULL | Sleep   |    6 | 2     | NULL             |
|    2 | root | 127.0.0.1 | NULL | Query   |    0 | 2     | show processlist |
+------+------+-----------+------+---------+------+-------+------------------+
2 rows in set (0.00 sec)

This pr:

mysql> show processlist;
+------+------+-----------------+------+---------+------+-------+------------------+
| Id   | User | Host            | db   | Command | Time | State | Info             |
+------+------+-----------------+------+---------+------+-------+------------------+
|    1 | root | 127.0.0.1:49032 | NULL | Sleep   |   10 | 2     | NULL             |
|    2 | root | 127.0.0.1:49034 | NULL | Query   |    0 | 2     | show processlist |
+------+------+-----------------+------+---------+------+-------+------------------+
2 rows in set (0.00 sec)

Check List

Tests

• Unit test
• Manual test (add detailed scripts or steps below)

Code changes

• Has exported function/method change

Side effects

• Increased code complexity

Related changes

[wshwsh12]

/run-all-tests

[codecov]

Codecov Report

Merging #11069 into master will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             master     #11069   +/-   ##
===========================================
  Coverage   81.1622%   81.1622%           
===========================================
  Files           419        419           
  Lines         90053      90053           
===========================================
  Hits          73089      73089           
  Misses        11700      11700           
  Partials       5264       5264

[wshwsh12]

/run-all-tests

[wshwsh12]

/run-integration-common-test

[XuHuaiyu]

Can we put this check outside of if s.sessionVars.User != nil {?

[lysu]

hi @wshwsh12 , ConnectionInfo should better not use in Non-plugin function... that structure maybe contain more info fields and be more heavy in future.

how about add a new ClientConn interface and make server.clientConn impl that interface then save it in SessionVars? current question is we can not get clientConn from session?