MySQL Bugs: #72531: Memcached and Semisync Replication Plugin are Off on Server Status page

Bug #72531	Memcached and Semisync Replication Plugin are Off on Server Status page
Submitted:	4 May 2014 14:35	Modified:	5 Sep 2014 4:56
Reporter:	Nicolas De Rico	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Workbench: Administration	Severity:	S3 (Non-critical)
Version:	6.1.5.11774	OS:	MacOS (10.9)
Assigned to:		CPU Architecture:	Any
Tags:	memcached, MySQL Workbench, semisync

Description:
The Memcached and Semi-Sync replication features are enabled and actively in-use but MySQL Workbench does not turn on the light for these features on the "Server Status" page.  Note that the status variables for semisync are correctly reported in the "System and Status Variables" page.

Master server:
Rpl_semi_sync_master_status..... ON
Rpl_semi_sync_master_clients..... 1

Slave server:
Rpl_semi_sync_slave_status..... ON

How to repeat:
1- Enable these two features:

Master:
[mysqld]
...
plugin-load = daemon_memcached=libmemcached.so;rpl_semi_sync_master=semisync_master.so
rpl_semi_sync_master_enabled = 1
gtid_mode = ON
enforce-gtid-consistency = 1
log-slave-updates = TRUE
...

Slave:
[mysqld]
...
plugin-load=rpl_semi_sync_slave=semisync_slave.so
rpl_semi_sync_slave_enabled=1
gtid_mode=ON
enforce-gtid-consistency=1
log-slave-updates=TRUE
...

2- Start the Master and Slave servers and start replication

# service mysql start (both master and slave)

Connect to slave and run:
mysql> START SLAVE; (on slave)

Connect to master and run:
mysql> show status like 'Rpl_semi_sync_master_clients';
+------------------------------+-------+
| Variable_name                | Value |
+------------------------------+-------+
| Rpl_semi_sync_master_clients | 1     |
+------------------------------+-------+
1 row in set (0.00 sec)

3- Prove that memcached is working on Master

# telnet localhost 11211
Trying ::1...
Connected to localhost.
Escape character is '^]'.
^]
telnet> quit

4- Connect to both Master and Slave with MySQL Workbench and see if Status lights are enabled for these features.  It seems that Memcached should be turned on on Master and Semisync should be turned on on both.

Hello Nicolas,

Thank you for the bug report.
Verified as described.

How to repeat:

Set up Semi sync replication as explained here https://dev.mysql.com/doc/refman/5.5/en/replication-semisync-installation.html

From WB -> Check "Server Status" for both Master/Slave and compare it with the settings from mysql> prompt.

master> show variables like 'rpl_semi_sync%';
+------------------------------------+-------+
| Variable_name                      | Value |
+------------------------------------+-------+
| rpl_semi_sync_master_enabled       | ON    |
| rpl_semi_sync_master_timeout       | 1000  |
| rpl_semi_sync_master_trace_level   | 32    |
| rpl_semi_sync_master_wait_no_slave | ON    |
+------------------------------------+-------+
4 rows in set (0.00 sec)

slave> show variables like 'rpl_semi_sync%';
+---------------------------------+-------+
| Variable_name                   | Value |
+---------------------------------+-------+
| rpl_semi_sync_slave_enabled     | ON    |
| rpl_semi_sync_slave_trace_level | 32    |
+---------------------------------+-------+
2 rows in set (0.00 sec)

Thanks,
Umesh

Master status

Attachment: Master_A.png (image/png, text), 40.59 KiB.

slave server status

Attachment: Slave_B.png (image/png, text), 33.56 KiB.

Posted by developer:
 
Fixed by setting the proper variables.

Fixed as of the upcoming MySQL Workbench 6.2.2 release, and here's the changelog entry:

The "Server Status" page did not recognize the enabled Memcached and
Semi-Sync replication features. The status light for these features did
not change from red to green. The "System and Status Variables" page
reported the correct values for these features.

Thank you for the bug report.