Category Archives: MySQL
Transactions and code testing
A little while ago I worked with a customer to migrate their DB from using MyISAM to InnoDB (something I definitely don’t mind doing!) I set up a smaller test instance with all tables using the InnoDB engine as part … Continue reading
Site slow after scaling out? Yeah, possibly!
So, doing the maths, you’re seeing 25*0.2*50= 250ms in just network latency per page load for your SQL queries. This is obviously a lot more than you see over a local UNIX socket. Continue reading
A look at MySQL 5.5 semi synchronous replication
This mode of replication is called semisynchronous due to the fact that it only guarantees that at least one of the slaves have written the transaction to disk in its relay log, not actually committed it to its data files. It guarantees that the data exists by some means somewhere, but not that it’s retrievable through a MySQL client. Continue reading
Don’t fix, work around – MySQL
Sun decided to not go down the route of reviewing and accepting the patches, but are now suggesting – are you sitting down? – running multiple instances on the same hardware. Continue reading
Resyncing slaves with slaves
When dealing with replicated setups with two or more slaves sharing a master, it appears as if a lot of people overlook the obvious. You don’t need to take your master down to resync a slave. I was hoping I wouldn’t need to post about this, but I see people taking down their masters when they have perfectly healthy slaves way too often to let it slip.
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