New to TokuDB® v7.5 is a feature we’re calling “Read Free Replication” (RFR). RFR allows TokuDB replication slaves to process insert, update, and delete statements with almost no read IO. As a result, the slave can easily keep up with the master (no lag) as well as brings all the read IO capacity of the slave for read-scaling your workload.

The goal of this blog is two-fold: (1) to cover why RFR is important and how RFR works and (2) to run a simple before/after benchmark showing the impact of RFR on a well known workload. Later this week I’ll post another blog showing other interesting use-cases for RFR beyond this first benchmark.

Read Free Replication: The Why and How

In MySQL, a replication slave does less work than the master because there is no need for a slave to execute SELECT statements (only INSERT, UPDATE, and DELETE). However, a MYSQL slave can struggle to keep up with the master because replication is …

September 22, 2014 By Severalnines

Need to add phone and SMS alerting to ClusterControl? ClusterControl 1.2.8 introduces support for PagerDuty, an alerting service for Ops teams to schedule on-calls and add phone and SMS notifications to IT tools. By integrating PagerDuty with ClusterControl, you can start receiving phone, SMS and email notifications for all important database events as monitored by ClusterControl. Alerts go directly to the right person who can solve the issue.

This integration is possible thanks to a new plugin interface, that takes ClusterControl alarms in JSON format and outputs to an external system via plugins. Plugins can be either scripts or executable binaries.

We have built a few example …

This is the next chapter of the story started in my previous article and related to the updated results on LinkBench workload published by MariaDB..

Keeping in mind that the obtained results are completely opposite from both sides, I've started to investigate then the same LinkBench-150GB 64 concurrent users workload from the "most favorable" possible test conditions on the same 40cores-HT server as in my previous article:

• InnoDB Buffer Pool (BP) = 150G (so, all the data may remain in memory)
• innodb_flush_log_at_trx_commit=2 (so, REDO write are not flushed once per second and not on every transaction)
• no …

MySQL upgrades are necessary tasks and we field a variety of questions here at Percona Support regarding MySQL upgrade best practices. This post highlights recommended ways to upgrade MySQL in different scenarios.

Why are MySQL upgrades needed? The reasons are many and include: Access to new features, performance benefits, bug fixes…. However, MySQL upgrades can be risky if not tested extensively beforehand with your application because the process might break it, prevent the application from functioning properly – or performance issues could arise following the upgrade. Moreover, I suggest keeping an eye on new releases of MySQL and Percona Server – check what has changed in the …

It’s been a little while since I blogged on MySQL on POWER (last time was thinking that new releases would be much better for running on POWER). Well, I recently grabbed the MySQL 5.6.20 source tarball and had a go with it on a POWER8 system in the lab. There is good news: I now only need one patch to have it function pretty flawlessly (no crashes). Unfortunately, there’s still a bit of an odd thing with some of the InnoDB mutex code (bug filed at some point soon).

But, with this one patch applied, I was getting okay sysbench results and things are looking good.

Now just to hope the MySQL team applies my other patches that improve things on POWER. To be honest, I’m a bit disappointed many of them have sat there for this long… it doesn’t help build a development community when patches can sit for months without either …

Today we released TokuDB® v7.5, the latest version of Tokutek’s storage engine for MySQL and MariaDB.

I’ll be publishing two blogs next week to go into more details about our new “Read Free Replication”, but here are high level descriptions of the most important new features.

Read Free Replication

TokuDB replication slaves can now be configured to process the binary logs with virtually no read IO. This is accomplished via two new server parameters: one to allow the skipping of uniqueness checks (for inserts and updates), the other to eliminate read-before-write behavior (for updates and deletes). The two other conditions are that the slave must be in read-only mode and replication must be row based.

Hot Backup Now Supports Multiple Directories (Enterprise Edition)

The original implementation of our Hot Backup functionality was only capable of …

I was fortunate to attend an Ops discussion about databases at the OpenStack Summit Atlanta this past May as one of the panelists. The discussion was about deadlock issues OpenStack operators see with Percona XtraDB Cluster (of course this is applicable to any Galera-based solution). I asked to describe what they are seeing, and as it turned out, nova and neutron uses the SELECT … FOR UPDATE SQL construct quite heavily. This is a topic I thought was worth writing about.

Write set replication in a nutshell (with oversimplification)

Any node is writable, and replication happens in write sets. A write …

There are a lot of tools that generate test data.  Many of them have complex XML scripts or GUI interfaces that let you identify characteristics about the data. For testing query performance and many other applications, however, a simple quick and dirty data generator which can be constructed at the MySQL command line is useful.

First, let’s talk about what kind of data you can easily create with MySQL function calls:

You can generate a decimal number between zero and another number using the MySQL RAND() function like the following query (here between 0 and 10000):

SELECT RAND() * 10000;

Similarly, you can generate a random integer by adding the FLOOR() function:

SELECT FLOOR(RAND() * 10000)

You can generate a random string of 32 characters using MD5():

SELECT MD5(RAND() * 10000)

You can return a random integer between 500 and 1000 with the following:

pt-query-digest is a tool available from Percona for analysis of MySQL queries from slow log, general log and binary log files. It can also analyze queries from mysql processlist and tcpdump mysql data. It is one of the best tools for slow query analysis on mysql server and can help you to improve mysql performance and efficiency. This tool is part of Percona Toolkit, the well-known MySQL management software utility toolkit for MySQL server administration (of course it also works on MariaDB and Percona Server). Formerly, percona toolkit was known as maatkit and pt-query-digest was called mk-query-digest. It has lots of options available to explore. In this post we'll compare some of the different sources pt-query-digest can use.

Slow query logs

MySQL can log …

pt-query-digest is a tool available from Percona for analysis of MySQL queries from slow log, general log and binary log files. It can also analyze queries from mysql processlist and tcpdump mysql data. It is one of the best tools for slow query analysis on mysql server and can help you to improve mysql performance and efficiency. This tool is part of Percona Toolkit, the well-known MySQL management software utility toolkit for MySQL server administration (of course it also works on MariaDB and Percona Server). Formerly, percona toolkit was known as maatkit and pt-query-digest was called mk-query-digest. It has lots of options available to explore. In this post we'll compare some of the different sources pt-query-digest can use.

Slow query logs

MySQL can log …