October 24, 2014

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 […]

From zero to full visibility of MySQL in 3 minutes with Percona Cloud Tools

First, I would like to invite you to my webinar, “Monitoring All (Yes, All!) MySQL Metrics with Percona Cloud Tools,” on Wednesday, June 25 at 10 a.m. Pacific Daylight Time, where I will talk on the new features in Percona Cloud Tools, including monitoring capabilities. In this post I’d like to show the cool and […]

Semi-Sync replication performance in MySQL 5.7.4 DMR

I was interested to hear about semi-sync replication improvements in MySQL’s 5.7.4 DMR release and decided to check it out.  I previously blogged about poor semi-sync performance and was pretty disappointed from semi-sync’s performance across WAN distances back then, particularly with many client threads. The Test The basic environment of these tests was: AWS EC2 […]

Using Apache Hadoop and Impala together with MySQL for data analysis

Apache Hadoop is commonly used for data analysis. It is fast for data loads and scalable. In a previous post I showed how to integrate MySQL with Hadoop. In this post I will show how to export a table from  MySQL to Hadoop, load the data to Cloudera Impala (columnar format) and run a reporting […]

How to find bugs in MySQL

Finding bugs in MySQL is not only fun, it’s also something I have been doing the last four years of my life. Whether you want to become the next Shane Bester (who is generally considered the most skilled MySQL bug hunter worldwide), or just want to prove you can outsmart some of the world’s best […]

How to monitor ALTER TABLE progress in MySQL

While working on a recent support issue as a Percona Support Engineer,  I got one question from a customer asking how to monitor ALTER TABLE progress. Actually, for MySQL 5.5 and prior versions, it’s quite difficult to ALTER the table in a running production environment especially for large tables (with millions records). Because it will rebuild and lock the table […]

10 MySQL settings to tune after installation

When we are hired for a MySQL performance audit, we are expected to review the MySQL configuration and to suggest improvements. Many people are surprised because in most cases, we only suggest to change a few settings even though hundreds of options are available. The goal of this post is to give you a list […]

Percona Server 5.5.34-32.0 is now available

Percona is glad to announce the release of Percona Server 5.5.34-32.0 on October 28th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.34, including all the bug fixes in it, Percona Server 5.5.34-32.0 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release […]

Innotop: A real-time, advanced investigation tool for MySQL

GUI monitoring tools for MySQL are not always suitable for all our needs or situations. Most of them are designed to provide historical views into what happens to our database over time rather then real-time insight into current MySQL server status. Excellent free tools for this include Cacti, Zabbix, Ganglia, Nagios, etc. But each of […]

Percona Server 5.5.32-31.0 now available

Percona is glad to announce the release of Percona Server 5.5.32-31.0 on July 2nd, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.32, including all the bug fixes in it, Percona Server 5.5.32-31.0 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release […]