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Published 20 hours ago • verified publisher icon cenalulu

Lost Writer VIP After "set_online" issued when Master is Behind the Current Master

Open cenalulu opened this issue 11 years ago • 0 comments

Consider a setup enviroment as below: DB1 ADMIN_OFFLINE DB2 ONLINE ( writer-vip, reader-vip )

DB1 is the preferred writer and has been OFFLINE for a long time. When "mmm control set_online DB1" is issued, writer-vip will removed before DB1 catch up with DB2. During the period when DB1 is catching up the replication lag, "writer-vip" cannnot be accessed.

In current mysql-mmm 2.2.1 , the set_online switch procedure can be summarize as below:

  1. remove writer-vip from DB2
  2. tell DB1 ONLINE
  3. DB1 execute start slave; Return success until catch up DB2
  4. attach writer-vip to DB1

During step3，the writer-vip cannot be accessed

cenalulu avatar Mar 01 '13 05:03 cenalulu