by Przemysław Malkowski | Jan 5, 2015 | Insight for DBAs, MariaDB, MySQL, Percona Software
Sometimes it is desired to use particular software versions in production, and not necessary the latest ones. There may be several reasons for that, where I think the most common is when a new version should spend some time in testing or a staging environment before...
by Arunjith Aravindan | Jan 2, 2015 | MySQL, Percona Software
The MySQL query cache is one of the prominent features in MySQL and a vital part of query optimization. It is important to know how the MySQL query cache works, as it has the potential to cause significant performance improvements – or a slowdown – of your...
by Stephane Combaudon | Dec 30, 2014 | MySQL, Percona Software
State Snapshot Transfer (SST) is used in Percona XtraDB Cluster (PXC) when a new node joins the cluster or to resync a failed node if Incremental State Transfer (IST) is no longer available. SST is triggered automatically but there is no magic: If it is not configured...
by Bill Karwin | Dec 29, 2014 | Insight for DBAs, MySQL, Percona Software
Some time ago, Peter Zaitsev posted a blog titled “How well does your table fits in innodb buffer pool?” He used some special INFORMATION_SCHEMA tables developed for Percona Server 5.1 to report how much of each InnoDB table and index resides in your...
by Peter Zaitsev | Dec 24, 2014 | Insight for DBAs, MySQL
It has been a while since I have looked at InnoDB crash recovery. A lot has change in the last few years – we have serious crash recovery performance improvements in MySQL 5.5 and MySQL 5.6, we have solid state drives raising as typical high performance IO...
by David Busby | Dec 23, 2014 | Insight for DBAs, MySQL, Security
This is a long overdue blog post from London’s 44con Cyber Security conference back in September. A lot of old memories were brought to the front as it were; the one I’m going to cover in this blog post is: file carving. So what is file carving? despite...
by Jay Janssen | Dec 22, 2014 | MySQL, Percona Software
Background on Backup Locks I was very excited to see Backup locks support in release notes for the latest Percona XtraDB Cluster 5.6.21 release. For those who are not aware, backup locks offer an alternative to FLUSH TABLES WITH READ LOCK (FTWRL) in
by Karthik Appigatla | Dec 19, 2014 | MySQL
Please note, a more up-to-date follow-up post is here: Storing UUID and Generated Columns A few years ago Peter Zaitsev, in a post titled “”There is timestamp based part in UUID which has similar properties to auto_increment and which could be used to have...
by Stephane Combaudon | Dec 18, 2014 | Insight for DBAs, MySQL, Percona Software
HAProxy is frequently used as a software load balancer in the MySQL world. Peter Boros, in a past post, explained how to set it up with Percona XtraDB Cluster (PXC) so that it only sends queries to available nodes. The same approach can be used in a regular...
by Peter Zaitsev | Dec 17, 2014 | Insight for DBAs, MySQL
I believe InnoDB storage engine architecture is great for a lot of online workloads, however, there are no silver bullets in technology and all design choices have their trade offs. In this blog post I’m going to talk about one important InnoDB limitation that...
by Daniel Guzmán Burgos | Dec 10, 2014 | Insight for DBAs, MySQL
Disclaimer: Reset the MySQL root password at your own risk! It doesn’t apply if you’re using Pluggable authentication and certainly won’t be usable if/when MySQL system tables are stored on InnoDB What is the situation? The situation is the classic...
by Muhammad Irfan | Dec 9, 2014 | Insight for DBAs, MySQL
In MySQL 5.6 Oracle introduced a Transportable Tablespace feature (copying tablespaces to another server) and Percona Server adopted it for partial backups which means you can now take individual database or table backups and your destination server can be a vanilla...
by Jay Janssen | Dec 3, 2014 | MySQL, Percona Software
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...
by Andrew Moore | Dec 2, 2014 | Insight for DBAs, MySQL, Percona Services
This post is a follow-up to my November 19 webinar, “Tips from the Trenches: A Guide to Preventing Downtime for the Over-Extended DBA,” during which I described some of the most common reasons DBAs experience avoidable downtime. The session was aimed at...
by Stephane Combaudon | Dec 1, 2014 | Insight for DBAs, MySQL, Percona Software
By default in MySQL 5.6, each time MySQL is started (regular start or crash recovery), it iterates through all the binlog files when GTIDs are not enabled. This can take a very long time if you have a large number of binary log files. MySQL and Percona Server 5.6.21+...
by Peter Zaitsev | Nov 26, 2014 | Benchmarks, MySQL
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%...
by Jay Janssen | Nov 25, 2014 | MySQL, Security
I log into a lot of different servers running MySQL and one of the first things I do is create a file in my home directory called ‘.my.cnf’ with my credentials to that local mysql instance: [client] user=root password=secret 123...
by Stephane Combaudon | Nov 24, 2014 | Insight for DBAs, MySQL
People using OpenStack Trove instances can hit a common issue in the MySQL world: how to perform schema change operations while minimizing the impact on the database server? Let’s explore the options that can allow online schema changes. Summary With MySQL 5.5,...
by Miguel Angel Nieto | Nov 20, 2014 | Insight for DBAs, MySQL
Performance Schema (P_S) has been available since MySQL 5.5, more than 4 years ago. It is still difficult to see production servers with P_S enabled, even with MySQL 5.6 where the feature is enabled by default. There have been several complaints like the overhead,...
by Arunjith Aravindan | Nov 19, 2014 | Insight for DBAs, MySQL, Percona Software
You might have encountered situations where you had to kill some specific select queries that were running for long periods and choking the database. This post will go into more detail with an example of report query offloading. Report query (select) offloading to a...
