With Performance Schema improvements in MySQL 5.6 I think we’re in the good shape with insight on what is causing performance bottlenecks as well as where CPU resources are spent. (Performance Schema does not accounts CPU usage directly but it is something which can be relatively easily derived from wait and stage information). Where we’re [...]
Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory than you would expect, causing swapping or other [...]
Using Flexviews – part one, introduction to materialized views
March 23, 2011 By 3 Comments
If you know me, then you probably have heard of Flexviews. If not, then it might not be familiar to you. I’m giving a talk on it at the MySQL 2011 CE, and I figured I should blog about it before then. For those unfamiliar, Flexviews enables you to create and maintain incrementally refreshable materialized [...]
Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
There are many angles you can look at the system to predict in performance, the model baron has published for example is good for measuring scalability of the system as concurrency growths. In many cases however we’re facing a need to answer a question how much load a given system can handle when load is [...]
Introducing tcprstat, a TCP response time tool
August 31, 2010 By 13 Comments
Ignacio Nin and I (mostly Ignacio) have worked together to create tcprstat[1], a new tool that times TCP requests and prints out statistics on them. The output looks somewhat like vmstat or iostat, but we’ve chosen the statistics carefully so you can compute meaningful things about your TCP traffic. What is this good for? In [...]
Why Swapping is bad for MySQL Performance ?
January 18, 2010 By 11 Comments
So you get MySQL or other applications using too much memory on the box or OS behaving funny and using more memory for cache and pushing application to the swap. This causes swapping and causes performance problems. This much is obvious. But how bad is it ? Should you count it same as normal Disk [...]
10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
People are sometimes contacting me and asking about bugs like this which provide a trivial way to crash MySQL to the user with basic privileges and asking me what to do. My answer to them is – there is nothing new to it and they just sit should back and relax Really – there are [...]
Read Buffers, mmap, malloc and MySQL Performance
September 12, 2007 By 8 Comments
Monty Taylor posted interesting investigation of the fact read_buffer_size variable affects connection speed. This is not something you would expect right ? me too. Not only global user data is expected to be cached on startup but even if it is not why would you do full table scan to fetch single user information ? [...]
Withdrawal of Memory allocation in Stored Function
September 7, 2007 By 1 Comment
Returning to my post about memory consumption with Stored Function at this moment I want to annul that post. Trying to repeat described behavoir I cannot repeat that again and probably there was something wrong with the whole box, not MySQL. I apologize if it was confusing. Although I am almost sure this topic will [...]
Mail clients and Databases
March 13, 2007 By 14 Comments
I get a lot of mail and I prefer to store it for long time if not forever. With modern hard disk sizes it should not be problem at all, but because of how mailing programs are written it causes a lot of problems. I’ve tried a lot of programs – Kmail, Evolution, Thunderbird on [...]
