Bug #77963 Relay_Log_Pos is struck at 326 for one of the Slave in Multi-Source replication
Submitted: 6 Aug 2015 11:39
Reporter: ramesh eslavath Email Updates:
Status: Open Impact on me:
None 
Category:MySQL Server: Replication Severity:S3 (Non-critical)
Version:5.7.7-rc-log MySQL Community Server (GPL OS:Linux (2.6.32-431.el6.x86_64 )
Assigned to: CPU Architecture:Any
Tags: Multi-Source replication 5.7

[6 Aug 2015 11:39] ramesh eslavath
Description:
 I have the below setup.replication form the master-A to Slave-D and master-B to Slave-D is working fine. replication from master-C to Slave-D is not good at all. 

       +--------+      +--------+     +--------+
       |master-A|      |master-B|     |master-C|
       +----v---+      +----v---+     +----v---+
            v               v              v
            v               v              v
            v               v              v
            v               v              v
          +-v---------------v--------------v--+
          |              Slave-D	      |
          +-----------------------------------+

There are conituos updates happening on master-C(Read_Master_Log_Pos,Exec_Master_Log_Pos are being changed continuously)
when I do, show slave status FOR CHANNEL "master-C"\G
Relay_Log_Pos remains the same for this channel, every time it is struck at 326 position.
when I do flush logs on slave, Relay_Log_File is changing and after time Relay_Log_Pos  is gettign struck at position 326. I dont see any replciation delay(Seconds_Behind_Master=0) allways and there is nothing written in the error log.

when I manually insert a data into some test table on the database, data is being replicated to SLAVE-D and there is change in Relay_Log_Pos to 568 and it is struck here.

I resynced the database in slave-D several times with that of master-C. and tried several channel names.

VERSIONS

MASTER-A :5.6.14-enterprise-commercial-advanced-log MySQL Enterprise Server - Advanced Edition (Commercial)
MASTER-B : 5.6.14-enterprise-commercial-advanced-log MySQL Enterprise Server - Advanced Edition (Commercial)
MASTER-C :earlier it was 5.6.14. I thought above error would go if I upgrade to 5.6.25. but, issue remains the same even after upgrading to 5.6.25.

How to repeat:
I followed the steps given in http://dev.mysql.com/doc/refman/5.7/en/replication-multi-source-tutorials.html
for "Adding a GTID Based Master to a Multi-Source Replication Slave"