One of the common causes of downtime with MySQL is running out of connections. Have you ever seen this error? “ERROR 1040 (00000): Too many connections.” If you’re working with MySQL long enough you surely have. This is quite a nasty error as it might cause complete downtime… transient errors with successful transactions mixed with […]
Earlier this month I wrote about vmstat iowait cpu numbers and some of the comments I got were advertising the use of util% as reported by the iostat tool instead. I find this number even more useless for MySQL performance tuning and capacity planning. Now let me start by saying this is a really tricky and deceptive number. Many […]
Monitoring MySQL and effectively managing it can be challenging. Identifying issues before they grow into performance problems that impact end users can be crucial. Knowing which tools to use, which key metrics to monitor, and how to resolve issues can be enormously important. When considering these facts, we at Percona decided to take steps to […]
One of the common tasks requested by our support customers is to optimize slow queries. We normally ask for the table structure(s), the problematic query and sample data to be able to reproduce the problem and resolve it by modifying the query, table structure, or global/session variables. Sometimes, we are given access to the server […]
I am proud to announce Percona Cloud Tools, the next generation of tools for MySQL. I have been developing tools for MySQL for 10 years. For the last 5 years, I have been developing Percona Toolkit (formerly “Maatkit”). Almost 1 year ago, we began developing Percona Cloud Tools (PCT), first in-house, then in private beta, […]
Recently some of my fellow Perconians and I have noticed a bit of an uptick in customer cases featuring the following error message:
SQLSTATE[HY000]  Can't create a new thread (errno 11); if you are not
out of available memory, you can consult the manual for a possible OS-dependent bug.
The canonical solution to this issue, if you do a bit of Googling, is to increase the number of processes / threads available to the MySQL user, typically by adding a […]
One of the more common questions I get asked is which Linux distribution I would use for a MySQL database server. Bearing the responsibility for someone else’s success means I should advise something that is stable, reliable, easy to manage and has plenty of resources available online. It should also allow running MySQL without too […]
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 […]
I vaguely recall a couple of blog posts recently asking something like “what’s the formula to compute mysqld’s worst-case maximum memory usage?” Various formulas are in wide use, but none of them is fully correct. Here’s why: you can’t write an equation for it.
There are interesting posts these day about future of MySQL Replication by Brian Frank and Arjen. I think it very interesting to take a look at a bit bigger picture using framework from Innovators Dilemma and Innovators Solution. I’m not going to speak about disruption and commoditisation of Database Market, leaving this for Market talks, […]