Search Results for: mysql logs

Be careful rotating MySQL logs

If you enable logging of all queries as “slow queries” using the patch or MySQL 5.1 you can get log file to grow huge. Same may happen with general log file. In some cases we’ve got log file sizes of 100G or more which may need to be cleaned up. Here is some danger waiting […]

Identifying useful info from MySQL row-based binary logs

As a MySQL DBA/consultant, it is part of my job to decode the MySQL binary logs – and there are a number of reasons for doing that. In this post, I’ll explain how you can get the important information about your write workload using MySQL row-based binary logs and a simple awk script. First, it […]

Rotating MySQL slow logs safely

This blog post is part two of two. Like part one, published Wednesday, this is a cross-post from Groupon’s engineering blog. Thanks again to Kyle Oppenheim at Groupon. And one more reminder that I’ll be at the Percona Live MySQL Conference and Expo next week in Santa Clara, California so look for me there. You […]

Auditing MySQL with McAfee and MongoDB

Greetings everyone! Let’s discuss a 3rd Party auditing solution to MySQL and how we can leverage MongoDB® to make sense out of all of that data. The McAfee MySQL Audit plugin does a great job of capturing, at low level, activities within a MySQL server. It does this through some non-standard APIs which is why installing […]

New PERFORMANCE_SCHEMA defaults in MySQL 5.7.7

I thought it was worth a moment to reiterate on the new Performance Schema related defaults that MySQL 5.7.7 brings to the table, for various reasons. For one, most of you might have noticed that profiling was marked as deprecated in MySQL 5.6.7. So it is expected that you invest into learning more about Performance […]

Optimizer hints in MySQL 5.7.7 – The missed manual

In version MySQL 5.7.7 Oracle presented a new promising feature: optimizer hints. However it did not publish any documentation about the hints. The only note which I found in the user manual about the hints is: It is now possible to provide hints to the optimizer by including /*+ … */ comments following the SELECT, […]

The value of MySQL Support

Years ago when I worked for the MySQL Support organization at the original MySQL AB, we spoke about MySQL Support as insurance and focused on a value proposition similar to that of car insurance. For your car to be fully covered, you must purchase car insurance before the incident happens – in fact most places […]

Choosing a good sharding key in MongoDB (and MySQL)

MongoDB 3.0 was recently released. Instead of focusing on what’s new – that is so easy to find, let’s rather talk about something that has not changed a lot since the early MongoDB days. This topic is sharding and most specifically: how to choose a good sharding key. Note that most of the discussion will also […]

Deep dive into MySQL’s innochecksum tool

One of our Percona Support customers recently reported that Percona XtraBackup failed with a page corruption error on an InnoDB table. The customer thought it was a problem or bug in the Percona XtraBackup tool. After investigation we found that an InnoDB page was actually corrupted and a Percona XtraBackup tool caught the error as […]