Bug #77475 documentation - replication problems - skip-networking is allowed on slaves
Submitted: 24 Jun 2015 23:18 Modified: 17 Mar 2020 16:56
Reporter: Daniel Black (OCA) Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Cluster: Replication Severity:S3 (Non-critical)
Version:5.6.25 OS:Any
Assigned to: MySQL Verification Team CPU Architecture:Any

[24 Jun 2015 23:18] Daniel Black
Description:
https://dev.mysql.com/doc/refman/5.6/en/replication-problems.html about 1/2 way down suggests --skip-networking on slaves can cause a non-working slave.

This was fixed sometime and the documentation hasn't been updated here.

How to repeat:
mysql> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|         123 |
+-------------+
1 row in set (0.00 sec)

mysql>
mysql>
mysql> change master to master_host='127.0.0.1', master_port=5625, master_user='replica';
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> show warnings;
+-------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Level | Code | Message                                                                                                                                                                                                                                                                              |
+-------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Note  | 1759 | Sending passwords in plain text without SSL/TLS is extremely insecure.                                                                                                                                                                                                               |
| Note  | 1760 | Storing MySQL user name or password information in the master info repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START SLAVE; see the 'START SLAVE Syntax' in the MySQL Manual for more information. |
+-------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

mysql> show global variables like '%network%';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| skip_networking | ON    |
+-----------------+-------+
1 row in set (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.00 sec)

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| foo                |
| mysql              |
| performance_schema |
+--------------------+
4 rows in set (0.00 sec)

Suggested fix:

correct documentation to remove need for skip-networking on a replication slave.