October 23, 2014

Paris OpenStack Summit Voting – Percona Submits 16 MySQL Talks

MySQL plays a critical role in OpenStack. It serves as the host database supporting most components such as Nova, Glance, and Keystone and is the most mature guest database in Trove. Many OpenStack operators use Percona open source software including the MySQL drop-in compatible Percona Server and Galera-based Percona XtraDB Cluster as well as tools such as Percona XtraBackup and Percona Toolkit. […]

Summertime Percona MySQL training update

Now that June has arrived it is time to plan what you will do over the summer months. In addition to your summer vacation plans, give thought to MySQL training for you and your team. Summer is the time to brush up on those critical skills needed to ensure all systems are ready for the holiday […]

Replication checksums in MySQL 5.6

MySQL 5.6 has an impressive list of improvements. Among them, replication checksums caught my attention as it seems that many people misunderstand the real added value of this new feature. I heard people think that with replication checksums, data integrity between the master and its replicas is now enforced. As we’ll see, it’s not that […]

DBD::mysql 4.014 breaks pt-table-checksum 2.0

DBD::mysql 4.014 breaks pt-table-checksum 2.0.  The cause is unknown, but the effect is a lot of errors like: DBD::mysql::st execute failed: called with 2 bind variables when 6 are needed [for Statement "..." with ParamValues: ...] at ./pt-table-checksum line 7216. The fix is simple: upgrade (or even downgrade) DBD::mysql to any version except 4.014. To […]

Modeling MySQL Capacity by Measuring Resource Consumptions

There are many angles you can look at the system to predict in performance, the model baron has published for example is good for measuring scalability of the system as concurrency growths. In many cases however we’re facing a need to answer a question how much load a given system can handle when load is […]

Autumn: A season of MySQL-related conferences. Here’s my list

Autumn is a season of MySQL-related conferences and I’m about to hit the road to speak and attend quite a  few of them. This week I’ll participate in All Things Open, a local conference for me here in Raleigh, N.C. and therefore one I do not have to travel for. All Things Open explores open source, […]

Percona Toolkit for MySQL with MySQL-SSL Connections

I recently had a client ask me how to use Percona Toolkit tools with an SSL connection to MySQL (MySQL-SSL). SSL connections aren’t widely used in MySQL due to most installations being within an internal network. Still, there are cases where you could be accessing MySQL over public internet or even over a public “private” […]

How to avoid hash collisions when using MySQL’s CRC32 function

Percona Toolkit’s  pt-table-checksum performs an online replication consistency check by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master – and the tool pt-table-sync synchronizes data efficiently between MySQL tables. The tools by default use the CRC32. Other good choices include MD5 and SHA1. If you have installed the FNV_64 user-defined function, pt-table-sync will […]

MySQL compression: Compressed and Uncompressed data size

MySQL has information_schema.tables that contain information such as “data_length” or “avg_row_length.” Documentation on this table however is quite poor, making an assumption that those fields are self explanatory – they are not when it comes to tables that employ compression. And this is where inconsistency is born. Lets take a look at the same table […]

MySQL Replication: ‘Got fatal error 1236′ causes and cures

MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration. In order to synchronize data between master and slaves you need to make sure that data transfers smoothly, and to do so you need to act promptly regarding replication errors to continue […]