The latest from the MySQL community

We’ve recently added the ability to monitor MySQL query performance statistics from MySQL’s PERFORMANCE_SCHEMA, and there were a number of lessons learned. There are definitely right and wrong ways to do it. If you are looking to the P_S tables for monitoring MySQL query performance, this blog post might save you some time and mistakes.

What Is The Performance Schema?

First, a quick introduction. The Performance Schema includes a set of tables that give information on how statements are performing. Most of the P_S tables follow a set of predictable conventions: there’s a set of tables with a limited set of full-granularity current and/or historical data, which is aggregated into tables that accumulate over time. In the case of statements, there’s a table of current statements, which feeds into a statement history, that accumulates into statement summary statistics. The tables are named as follows:

The PostgreSQL manual says:

"The standard's definition of the behavior of temporary tables is widely ignored. PostgreSQL's behavior on this point is similar to that of several other SQL databases."

The first sentence is false. The second sentence could be rephrased as "MySQL copied us", although nobody else did, as far as I know.

The standard's definition is widely followed

I base this claim on the documentation of DB2, Oracle Rdb, Oracle 12c, and …

“HBase and Hadoop are the only technologies proven to scale to dozens of petabytes on commodity servers, currently being used by companies such as Facebook, Twitter, Adobe and Salesforce.com.”–Monte Zweben.

Is it possible to turn Hadoop into a RDBMS? On this topic, I have interviewed Monte Zweben, Co-Founder and Chief Executive Officer of Splice Machine.

RVZ

Q1. What are the main challenges of applications and operational analytics that support real-time, interactive queries on data updated in real-time for Big Data?

Monte Zweben: Let’s break down “real-time, interactive queries on data updated in real-time for Big Data”. “Real-time, interactive queries” means that results need to be returned in milliseconds to a few seconds.
For “Data updated in real-time” to happen, …

By Erkan Yanar 02-11-2014

OpenStack is likely the most popular open-source cloud computing platform (for IaaS or PaaS). Running OpenStack for yourself or for customers you likely want to run it without losing data and be able to scale while business grows. In this blog we are going to give a short overview to the OpenStack architecture, focusing on the Database(MySQL/MariaDB) part. Then we are going to discuss why Galera is an essential building block to achieve HA of the database and provide scaling even for very big installations.

The quite basic setup consists of:

A dashboard (program codename Horizon) providing a WebUI to manage OpenStack. Authentication is done via the identity service (Keystone). The Images service (Glance) provides images i.e. Ubuntu LTS, Centos7, etc. to start from. The Nova service starts them on a compute node. If you like to have persistent volumes you can also …

After a long time, I finally had some time to write again, and this time I intend to keep a periodicity. The reason for my absence? Well now I have Dom Without further ADO, let’s get to the point, what… Continue Reading →

Continue reading What is Iptables, what it’s for, and how to use?

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MySQL database usage is popular in OpenStack. Core OpenStack services for Compute (Nova), Storage (Cinder), Neutron (Networking), Image (Glance) and Identity (Keystone) all use MySQL database.

MySQL – as the world’s most popular database, runs inside OpenStack Virtual Machines and serves as database backend to OpenStack cloud based applications. The MySQL instances can be configured to run in virtual machines manually (by simply installing MySQL inside a VM and running it) or can be created in an on-demand fashion by OpenStack Database-as-a-Service (Trove).

In either case, the MySQL data is mission-critical. OpenStack cloud administrators and cloud guests/tenants need the ability to backup and restore their MySQL databases. mysqldump is traditional way of doing MySQL backups and restores. However, based on previous experiences of the MySQL community, it is widely known that mysqldump has …

Podcasts Learning Performance

This week we discuss user statistics in the MariaDB and Percona forks of MySQL.

Podcasts Learning Performance

This week we discuss user statistics in the MariaDB and Percona forks of MySQL.

Today I read an article about how company X has improved things by amongst other things ditching JSON after 2 years of using it. Before I start on this subject I should say that JSON does have its place. If you have a web application where a browser is talking to a web server and in particular uses JavaScript then JSON is a good fit.

I've discussed this issue several times before with Brian Aker who works with me at HP's Advanced Technology Group and in the past I have been hit with the issues I'm going to talk about here.

JSON is human readable and easy to parse, that cannot be denied and for prototyping is good in a pinch. The first problem comes when you need to validate data. I've been stung many times by one end trying to read/write the JSON in a slightly different format to the other end, the end result is always not pretty. This is one advantage that XML and SOAP has going for it …

Benchmarking is a popular topic. People love drawing graphs as much as watching how X is 10% faster than Y; there must be something special in measurements.

For a DBA, however, more tangible improvements come from less popular area of database maintenance. While MariaDB spreads FUD around InnoDB (nonetheless still uses it) I have to admit InnoDB gets more friendly to DBAs.

In MySQL 5.6 new temporary table naming scheme was introduced – one of improvements. Invisible, yet important.

Temporary table names became more random and should not ever be reused.

Some time ago I wrote a post about how to remove …