Category Archives: MySQL

How does MySQL hide the command line password in ps?

If you do decide to write an application which takes a password (or any other sensitive information) on the command line, you can prevent other users on the system from easily seeing it like this Continue reading

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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

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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

Posted in MySQL, Sundry sysadmin | Leave a comment

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

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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

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