MySQL Incremental backups with Master-Slave replication

incremental-backupmaster-slaveMySQL

we have a MySQL system in Master-slave replication mode. Currently we are doing full backups with mysqldumps to a remote disk server.

I think is best to do one full dump and many small incremental backups. According to the MySQL manual, MySQL uses the binlogs to make theses incremental backups, flushing binlogs each time an incremental backup is completed. But we already use binlogs to achieve Master-Slave replication.

My question is: how does this incremental backup and binlogs flushing affect the master-slave replication?

P.S:forgot to say, most of the tables use InnoDB, the others use MyISAM

Best Answer

Well a packed question, let me try to answer all the issues you raised there.

Binary backups vs dumps

Right now you're using mysqldump to do full backups of your database, that's a good practice indeed but it can get a bit endearing when dealing with huge MySQL installations. Binary backups are good point in time backups, but you need two parts, one full binary backup (which needs to be consistent) and the binary diff logs. Of course the time for recovery for one an the other is drastically different too, it all depends as said on the size of your database and your turnover times.

How flushing the binlogs will affect replication

It won't affect replication if you flush the logs always after they've been transmitted to the slave, otherwise you'll run into some nasty issues due to the slave not being able to request the exact block of the binlog that it needs

Related Solutions

Mysql – Sporadic crash of master-slave MySQL replication process

Double check that your character sets on the databases and connections are what you expect them to be - your replication choking on a statement with a non-ASCII character is immediately suspicious.

Look at the master's binary log to see how the statement it logged is different from the statement that the replica is trying to execute - that will offer clues to the problem.

Sadly, you should also make sure that the versions of the server for both the master and slave are the same. I recently encountered a weird instance where we had bad SQL trying to update a non-NULL numeric column to NULL. In the version that the master was running, MySQL silently converted it to 0, but in the version that the replica was running, it was an error.

Also, instead of doing CHANGE MASTER to fix the replica, you should be doing

STOP SLAVE;
[correct and execute whatever statement is the problem]
SET GLOBAL sql_slave_skip_counter = 1;
START SLAVE;

http://dev.mysql.com/doc/refman/5.1/en/set-global-sql-slave-skip-counter.html

Mysql – How to load a database with foreign keys on the master without out breaking replication

Usually when you do a mysql load of a dump, you disable foreign key checks, then re-enable them, in fact it might do this by default. You simply need to do the same thing on the slave for the duration of the replication.

This is an import export guide:
http://technocation.org/files/doc/2010_06_BulkLoad.pdf

Disabling foreign keys:
http://gauravsohoni.wordpress.com/2009/03/09/mysql-disable-foreign-key-checks-or-constraints/

Best Answer

Related Solutions

Mysql – Sporadic crash of master-slave MySQL replication process

Mysql – How to load a database with foreign keys on the master without out breaking replication

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