MySQL Bugs: #21804: SHOW SLAVE HOSTS lists itself and other slaves on a SLAVE!

Bug #21804	SHOW SLAVE HOSTS lists itself and other slaves on a SLAVE!
Submitted:	24 Aug 2006 8:19	Modified:	29 Aug 2006 16:43
Reporter:	Oli Sennhauser	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	any, up to 5.0.24	OS:	n.a.
Assigned to:	Stefan Hinz	CPU Architecture:	Any

Description:
When I have a Master M and 2 Slaves S1 and S2 on the same host SHOW SLAVE HOSTS lists the slaves on M correctly but also list S1 and S2 on both hosts.

This IMHO is eighter a bug or not properly documented.

See also Bug: http://bugs.mysql.com/bug.php?id=13963

How to repeat:
Setup M and S1 and S2 on same host and set report_host and repot_port on both slaves.
master> show slave hosts;
+-----------+--------------+------+-------------------+-----------+
| Server_id | Host         | Port | Rpl_recovery_rank | Master_id |
+-----------+--------------+------+-------------------+-----------+
|        18 | Slave 5.0.22 | 3318 |                 0 |        15 |
|        28 | Slave 5.0.24 | 3328 |                 0 |        15 |
+-----------+--------------+------+-------------------+-----------+

slave1> show slave hosts;
+-----------+--------------+------+-------------------+-----------+
| Server_id | Host         | Port | Rpl_recovery_rank | Master_id |
+-----------+--------------+------+-------------------+-----------+
|        28 | Slave 5.0.24 | 3328 |                 0 |        15 |
|        18 | Slave 5.0.22 | 3318 |                 0 |        15 |
+-----------+--------------+------+-------------------+-----------+

slave2> show slave hosts;
+-----------+--------------+------+-------------------+-----------+
| Server_id | Host         | Port | Rpl_recovery_rank | Master_id |
+-----------+--------------+------+-------------------+-----------+
|        18 | Slave 5.0.22 | 3318 |                 0 |        15 |
|        28 | Slave 5.0.24 | 3328 |                 0 |        15 |
+-----------+--------------+------+-------------------+-----------+

Suggested fix:
Eighter fix this (IMHO this sould not be displayed on slave) or adapt documentation:

http://dev.mysql.com/doc/refman/5.0/en/show-slave-hosts.html
http://dev.mysql.com/doc/refman/5.0/en/replication-options.html

There are other commands allow to control master on slaves, so I classify it as documentation bug: there is not any information about GRANTs user with REPLICATION SLAVE privilege has.

The documentation doesn't say that replication slaves are reported *on* the master, but rather says this: "Displays a list of replication slaves currently registered with the master." If you think this should be restricted to work *on* the master only, please file a Server:Replication bug.

Documentation contains chapter "SQL Statements for Controlling Master Servers". 
This chapter contains, for example, "SHOW SLAVE HOSTS" statement working on slave and returns useful information and "PURGE MASTER LOGS" statement working on master only. But documentation contains no word about difference between these 2 statements: new user only can try these statements self to get exact information how they work or even make guesswork about work of these statements.

Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly, and will be included in the next release of the relevant products.