The architecture of MySQL-powered applications is one of my favorite topics to talk about. It’s a very important topic because if you do not get the architecture right then you’re very likely to fail with your project – either from the standpoint of failing with performance, high availability or security requirements… or failing to deliver […]
I’ve been running a benchmark today on my old test box with conventional hard drives (no raid with BBU) and noticed something unusual in the CPU utilization statistics being reported. The benchmark was run like this:
sysbench --num-threads=64 --max-requests=0 --max-time=600000 --report-interval=10 --test=oltp --db-driver=mysql --oltp-dist-type=special --oltp-table-size=1000000 --mysql-user=root --mysql-password=password run
Which means: create 64 threads and hammer the database with queries as quickly as possible. As the test […]
MySQL has status variables “questions” and “queries” which are rather close but also a bit different, making it confusing for many people. The manual describing it might not be very easy to understand:
The number of statements executed by the server. This variable includes statements executed within stored programs, unlike the Questions variable. It does not count COM_PING or COM_STATISTICS commands.
The number of statements executed by the server. This includes only statements sent to the server by clients and not statements executed within stored programs, unlike the Queries variable. This variable does not count COM_PING, COM_STATISTICS, COM_STMT_PREPARE, COM_STMT_CLOSE, or COM_STMT_RESET commands.
In a nutshell if you’re not using prepared statements the big difference between those is what “Questions” would count stored procedure calls as […]
Achieving the best possible MySQL Performance doesn’t have to be complicated. It’s all about knowing which tools are designed for the task at hand – along with some basic (yet often overlooked) best practices. Join me Wednesday, May 14 at 10 a.m. Pacific for a free webinar titled, “Practical MySQL performance optimization.” I’ll be sharing […]
Later this week I’m excited to depart on a trip to South America. First I will stop in Montevideo, Uruguay, to meet with Percona’s team out there as well as to participate in our next Percona University event on April 29. For those who do not know, Percona University events are free to attend and […]
Over the last few days, the Percona team has spent a lot of time evaluating the impact of the Heartbleed bug (CVE-2014-0160) for our customers and for the users of our software. We published a formal disclosure a few days ago. However, I thought a quick summary and some additional information would be good to […]
I’m looking forward to Wednesday’s joint webinar on MySQL clustering technologies with Matt Aslett, research director of data management and analytics over at 451 Research. We’ll be participating in a live, in-depth discussion of MySQL Clustering for High Availability and Scalability. Matt will present an overview of the trends driving adoption of clustering technology. He’ll […]
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 […]
When looking at queries that are candidates for optimization I often recommend that people look at rows_sent and rows_examined values as available in the slow query log (as well as some other places). If rows_examined is by far larger than rows_sent, say 100 larger, then the query is a great candidate for optimization. Optimization could […]
A couple of weeks ago, shortly after Vadim wrote about Percona Cloud Tools and using Slow Query Log to capture the data, Mark Leith asked why don’t we just use Performance Schema instead? This is an interesting question and I think it deserves its own blog post to talk about. First, I would say main […]