Search Results for: kernel

kernel_mutex problem cont. Or triple your throughput

This is to follow up my previous post with kernel_mutex problem. First, I may have an explanation why the performance degrades to significantly and why innodb_sync_spin_loops may fix it. Second, if that is correct ( or not, but we can try anyway), than playing with innodb_thread_concurrency also may help. So I ran some benchmarks with […]

MySQL benchmarks on eXFlash DIMMs

In this blog post, we will discuss MySQL performance on eXFlash DIMMs. Earlier we measured the IO performance of these storage devices with sysbench fileio. Environment The benchmarking environment was the same as the one we did sysbench fileio in. CPU: 2x Intel Xeon E5-2690 (hyper threading enabled) FusionIO driver version: 3.2.6 build 1212 Operating […]

Hyper-threading – how does it double CPU throughput?

The other day a customer asked me to do capacity planning for their web server farm. I was looking at the CPU graph for one of the web servers that had Hyper-threading switched ON and thought to myself: “This must be quite a misleading graph – it shows 30% CPU usage. It can’t really be […]

What happens when your application cannot open yet another connection to MySQL

Have you ever experienced a situation where one moment you can connect to the MySQL database and the next moment  you cannot, only to be able to connect again a second later? As you may know one cannot open infinite connections with MySQL. There’s a practical limit and more often than not it is imposed […]

Auto-bootstrapping an all-down cluster with Percona XtraDB Cluster

One new feature in Percona XtraDB Cluster (PXC) in recent releases was the inclusion of the ability for an existing cluster to auto-bootstrap after an all-node-down event.  Suppose you lose power on all nodes simultaneously or something else similar happens to your cluster. Traditionally, this meant manually re-bootstrapping the cluster, but not any more. How it […]

MySQL benchmarking: Know your baseline variance!

Often enough I find MySQL benchmark results where the difference between results is 1% or even less and some conclusions are drawn. Now it is not that 1% is not important – especially when you’re developing the product you should care about those 1% improvements or regressions because they tend to add up. However with […]

Optimizing MySQL for Zabbix

This blog post was inspired by my visit at the annual Zabbix Conference in Riga, Latvia this year, where I gave a couple of talks on MySQL and beyond. It was a two day single-track event with some 200 participants, a number of interesting talks on Zabbix (and related technologies) and really well-organized evening activities. […]

Facebook MySQL database engineers ready for Percona Live London 2014

With 1.28 billion active users, Facebook MySQL database engineers are active and extremely valuable contributors to the global MySQL community. So naturally they are also active participants of Percona Live MySQL conferences! And next week’s Percona Live London 2014 (Nov. 3-4) is no exception. (Register now and use the promotional code “Facebook” to save £30!) […]