03 Dec

Recent security woes in MySQL

For those who don't know, several security vulnerabilities in MySQL were discovered recently and published to the security mailing lists. Yet another time, remote attacker can badly hit your production systems causing long downtime.

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11 Jun

A security flaw in MySQL authentication. Is your system vulnerable?

A few days ago Sergei Golubchik of Monty Program sent an e-mail to the Open Source Security mailing list informing about a security vulnerability in MySQL authentication system. Under certain circumstances a remote attacker may easily gain access to MySQL database as any user and all they need to know is a valid user name (e.g. root user exists in nearly all installations). The problem has only been addressed in the most recent database versions.

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02 Jun

How to find MySQL binary logs, error logs, temporary files?

Have you ever spent a lot of time trying to locate where MySQL keeps some file? Here is a quick way to find all this information in one place.

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01 Jun

A small rant on Galera & XtraDB Cluster

I had to install Percona XtraDB Cluster, I think for the first time since it was announced stable. I remembered many problems I faced with beta releases, which was understandable given they were only for a preview, but this time I hoped for significant improvements.

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15 May

Why do threads sometimes stay in 'killed' state in MySQL?

Have you ever tried to kill a query, but rather than just go away, it remained among the running ones for an extended period of time? Or perhaps you have noticed some threads makred with killed showing up from time to time and not actually dying. What are these zombies? Why does MySQL sometimes seem to fail to terminate queries quickly? Is there any way to force the kill command to actually work instantaneously? This article sheds some light on it.

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