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I have async-Classic file based replication with 2 Nodes as Active - Active. R/W is happening on Primary Node (PN) only and Secondary Node (SN) has been setup as HA only. SN has been configured as read_only mode.

In case if PN Database goes down when I/O thread (of SN) trying to fetch bin-logs resulting which not all events got replicated to SN. Now , data comes in unsync state .

As per my another script i will re-direct all R/W operations to SN by disabling its read_only mode post PN goes down.

Now question is :

 Q. If i copy those binary logs from PN at point where replication got break and get it executed at SN end. how much it is feasible ?

       Things i Know :  For this , can i use execute mysqldump utility from
                        SN with its *read-binary-logs-from-server* 
                        parameter. This will copy the logs from PN to SN and
                        then i can execute it . But my doubt is , as PN DB
                        is down ( but VM box is running ), can i still be 
                        able to fetch bin-logs ?

Please give your feedback on this . How much this solution will work . I cannot use any other 3rd party tool or other modes of replication due to time constraints and cost constraints

                            *****EDIT*****

If DB at PN is down , i cannot make use of mysqldump .

What i have figured out is , we can take the position at which replication went down and i will fetch those records from binary logs and get it executed at SN. In this way un-replicated records get inserted at SN

  • The PN hardware is up, but you can't get mysqld to run?? – Rick James May 25 '17 at 5:33
  • yes PN machine is up , but for any reason mysqld went down – Ankit Kapoor May 25 '17 at 7:28

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