I'm setting up a mysql master-slave configuration, where slave is located on a much weaker sever.

Since, if I understand correctly, slave only works on updates/inserts, what are the most critical configuration parameters that I can adjust in slave's my.cnf to ensure best performance and smallest possible latency?

  • Master: 32Gb RAM, Slave: 4Gb RAM
  • Mostly innodb tables
  • Percona-server 5.5 on both master and slave

2 Answers 2


If your concern is about performance and you don't care about losing a small chunck of data(usually 1 second) in case of server crashes, I would change the follow variables:

A good option is to read this article, it's a general overview to how optimize innodb, it will work for your master and also to your slave.

If you are planning to upgrade to the percona server which implement features from MySQL 5.6, I would recommend that you increase the number of slave sql threads slave-parallel-workers

  • 2
    Thank you! Even innodb_flush_log_at_trx_commit=0 alone made 18 hour latency go away in just a few hours! Commented Apr 30, 2013 at 9:27
  • disable innodb_doublewrite will also brings you some improvement on I/O Commented Apr 30, 2013 at 9:35
  • Disabling innodb_doublewrite is really dangerous
    – Deinlandel
    Commented Jan 12, 2018 at 7:51

You just need to optimize for InnoDB environment. innodb_buffer_pool_size is still the key for performance.

And beacuse your slave server is weak than master, you might need to deal with replication lag. (i.e. Write to master, but cannot read data from slave immediately)

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