During the design period of a new cluster, it is always advised to have at least 3 nodes (this is the case with PXC but it’s also the same with PRM). But why and what are the risks ? The goal of having more than 2 nodes, in fact an odd number is recommended in [...]
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 [...]
How to Monitor MySQL with Percona’s Nagios Plugins
February 22, 2012 By 11 Comments
In this post, I’ll cover the new MySQL monitoring plugins we created for Nagios, and explain their features and intended purpose. I want to add a little context. What problem were we trying to solve with these plugins? Why yet another set of MySQL monitoring plugins? The typical problem with Nagios monitoring (and indeed with [...]
Configuring MySQL For High Number of Connections per Second
January 6, 2012 By 23 Comments
One thing I noticed during the observation was that there were roughly 2,000 new connections to MySQL per second during peak times. This is a high number by any account. When a new connection to MySQL is made, it can go into the back_log, which effectively serves as a queue for new connections on operating [...]
Announcing Percona Live MySQL Conference and Expo 2012
August 9, 2011 By 11 Comments
We’re thrilled to announce that we have signed a contract with the Hyatt Regency Santa Clara and the Santa Clara Convention Center, to host a Percona Live MySQL Conference and Expo on April 10-12, 2012. This event is part of our Percona Live series of conferences, but it’s not just another event in the series. [...]
Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we get from a proper IO alignment on a 4-disk RAID1+0 with 64k stripe element. I haven’t been running any benchmarks [...]
MySQL Connection Timeouts
April 19, 2011 By 4 Comments
Sometimes on very busy MySQL server you will see sporadic connection timeouts, such as Can’t connect to MySQL server on ‘mydb’ (110). If you have connects timed in your application you will see some successful connections taking well over the second. The problem may start very slow and be almost invisible for long time, for [...]
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 [...]
How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
We receive many requests for help with server stalls. They come under various names: lockup, freeze, sudden slowdown. When something happens only once or twice a day, it can be difficult to catch it in action. Unfortunately, this often leads to trial-and-error approaches, which can drag on for days (or even months), and cause a [...]
Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]
