by Muhammad Irfan | Feb 27, 2015 | Insight for DBAs, MySQL, Percona Software
DBAs often encounter situations where they need to kill queries to ensure there are no long-running queries on a MySQL server that would impact performance. Long-running queries can be the result of many factors. Fortunately, Percona Server contains some handy tools...
by Fernando Laudares Camargos | Feb 26, 2015 | Insight for DBAs, MySQL
If you use Percona Server 5.5 and you have configured it to use multiple buffer pool instances than sooner or later you’ll see the following lines on the server’s error log and chances are you’ll be worried about them: Shell InnoDB: detected cycle in...
by Alexander Rubin | Feb 25, 2015 | Insight for DBAs, MySQL
MySQL introduced the Event Scheduler in version 5.1.6. The Event Scheduler is a MySQL-level “cron job”, which will run events inside MySQL. Up until now, this was not a very popular feature, however, it has gotten more popular since the adoption of Amazon...
by Brock Wilson | Feb 24, 2015 | Benchmarks, MySQL, Percona Services, Percona Software
MySQL’s innodb_file_per_table is a wonderful thing – most of the time. Having every table use its own .ibd file allows you to easily reclaim space when dropping or truncating tables. But in some use cases, it may cause significant performance issues. Many...
by Fernando Laudares Camargos | Feb 20, 2015 | Insight for DBAs, MySQL, Percona Software
This past week was marked by a series of personal findings related to the use of Global Transaction IDs (GTIDs) on Galera-based clusters such as
by Stephane Combaudon | Feb 19, 2015 | MySQL
In a previous post, titled “Multi-threaded replication with MySQL 5.6: Use GTIDs,” I explained that using GTID replication is almost a requirement when using MySQL 5.6 MTS. Let’s see now how to perform the day-to-day operations when MTS and GTIDs are...
by Justin Swanhart | Feb 17, 2015 | MySQL
by Stephane Combaudon | Feb 13, 2015 | MySQL, Percona Software
Say you have a cluster with 3 nodes using Percona XtraDB Cluster (PXC) 5.6 and one asynchronous replica connected to node1. If asynchronous replication is using GTIDs, moving the replica so that it is connected to node2 is trivial, right? Actually replication can...
by Roel Van de Paar | Feb 4, 2015 | Insight for DBAs, Insight for Developers, MySQL
Being a QA Engineer, how would you feel if you had access to a framework which can generate 80+ crashes – a mix of hitting developer introduced assertions (situations that should not happen), and serious unforeseen binary crashes – for the world’s...
by David Busby | Jan 29, 2015 | MySQL, Security
Cloud security company Qualys announced Tuesday the issues prevalent in glibc since version 2.2 introduced in 2000-11-10 (the complete Qualys announcement may be viewed here). The vulnerability, CVE-2015-0235, has been dubbed “GHOST.” As the announcement...
by Stephane Combaudon | Jan 29, 2015 | Insight for DBAs, MySQL
MySQL 5.6 allows you to execute replicated events in parallel as long as data is split across several databases. This feature is named “Multi-Threaded Slave” (MTS) and it is easy to enable by setting slave_parallel_workers to a > 1 value. However if you...
by Peter Boros | Jan 26, 2015 | Benchmarks, MySQL
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...
by Michael Coburn | Jan 23, 2015 | MySQL, Percona Software
For months when speaking with customers I have been positioning Percona Cloud Tools (PCT) as a valuable tool for the DBA/Developer/SysAdmin but only recently have I truly been able to harness the data and make a technical recommendation to a customer that I feel would...
by David Ducos | Jan 21, 2015 | Benchmarks, Insight for DBAs, MySQL
Mydumper is known as the faster (much faster) mysqldump alternative. So, if you take a logical backup you will choose Mydumper instead of mysqldump. But what about the restore? Well, who needs to restore a logical backup? It takes ages! Even with Myloader. But this...
by Alok Pathak | Jan 20, 2015 | Insight for DBAs, MySQL
As a MySQL DBA/consultant, it is part of my job to decode the MySQL binary logs – and there are a number of reasons for doing that. In this post, I’ll explain how you can get the important information about your write workload using MySQL row-based binary...
by Peter Zaitsev | Jan 19, 2015 | Benchmarks, MySQL, Percona Software
A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single row. Today I wanted to look a bit deeper into the...
by Aurimas Mikalauskas | Jan 15, 2015 | Benchmarks, Insight for DBAs, MySQL
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%...
by Peter Zaitsev | Jan 14, 2015 | Benchmarks, MySQL
Over the past few months I’ve written a couple of posts about dangerous debt of InnoDB Transactional History and about the fact MVCC can be the cause of severe MySQL performance issues. In this post I will cover a related topic – InnoDB Transaction...
by Roman Vynar | Jan 7, 2015 | Insight for Developers, MySQL
This is yet another story of Django web-framework with time zone support and pain dealing with python datetimes and MySQL on the backend. In other words, offset-naive vs offset-aware datetimes. Shortly, more about the problem. After reading the official documentation...
by Miguel Angel Nieto | Jan 6, 2015 | Insight for DBAs, MySQL
We have been using SHOW ENGINE INNODB MUTEX command for years. It shows us mutex and rw-lock information that could be useful during service troubleshooting in case of performance problems. As Morgan Tocker announced in his blog post the command will be removed from...
