TokuDB offers high throughput for write intensive applications, and the throughput scales with the number of concurrent clients.  However, when the binary log is turned on, TokuDB 7.5.2 throughput suffers.  The throughput scaling problem is caused by a poor interaction between the binary log group commit algorithm in MySQL 5.6 and the way TokuDB commits transactions.   TokuDB 7.5.4 for Percona Server 5.6 fixes this problem, and the result is roughly an order of magnitude increase in SysBench throughput for in memory workloads.

MySQL uses two phase commit protocol to synchronize the MySQL binary log with the recovery logs of the storage engines when a transaction commits.  Since fsync’s are used to ensure the durability of the data in the various logs, and fsync’s can be very slow, the fsync can easily become a bottleneck.  A …

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 you should consider.

InnoDB is a multiversion concurrency control (MVCC) storage engine which means many versions of the single row can exist at the same time. In fact there can be a huge amount of such row versions. Depending on the isolation mode you have chosen, InnoDB might have to keep all row versions going back to the earliest active read view, but at the very least it will have to keep all versions going back to the start of SELECT query which is currently running.

In most cases this is not a big deal – if you have many short transactions happening you will have only a few row versions to deal with. If you just use the system for reporting queries but do not …

One of great innovation in MySQL 5.7 is memory summary tables в Performance Schema and corresponding views in sys schema

And as troubleshooting freak I have huge reason to greet this feature.

Before version 5.7 we had very limited abilities to diagnose memory issues in MySQL. We could use operating system tools, such as vmstat, top, free, but they only showed what MySQL server uses memory, but do not show how. In version 5.7 things changed.

Lets examine what can we study about memory usage by MySQL Server.

At first, this is total amount of memory, used by all internal MySQL structures:

mysql> select * from …

How to install osCommerce on Ubuntu 14.04 (Trusty Tahr)

This document describes how to install osCommerce in Ubuntu 14.04. Open Source Commerce (osCommerce) is a popular e-Commerce and online store-management software program that may be easily used on any web server with PHP and MySQL installed. osCommerce is available to users as a free software under the General Public License (GNU) The versatile and fuss-free software enables easy setting up and maintenance of e-stores using minimal effort. This tutorial describes the process of installing osCommerce on Ubuntu 14.04.

For an online shop, the website is the cash register. It has to be open for business 24 hours a day.

As the ops person on duty, when you get a call at 3am after your website went down, your priority number one is to restore the service asap. But why can we not have our application stack automatically recover, and not have the pager wake us at all? Why do we still stick to tedious manual processes, which take up time and resources, and hinder future growth?

Infrastructure automation isn’t easy, but it’s not rocket science either, says Riaan Nolan. Riaan has been in operations for the past decade, and has built over a dozen eCommerce properties. Automation is a worthwhile investment for retailers serious about eCommerce, but deciding on which tools to invest in can be a confusing and overwhelming process.

Join us for this webinar to understand the key pain points that online retailers experience which indicate it’s time …

Thanks to everyone who attended and participated in last week’s webinar on 'Galera Cluster for MySQL vs MySQL (NDB) Cluster: A High Level Comparison'. If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.

In this webinar, Severalnines VP of Products, Alex Yu, who was part of the team at Ericsson who originally developed the NDB storage engine in 2001, gave an overview of the two clustering architectures and discussed their respective strengths and weaknesses: 

1. MySQL Cluster architecture: strengths and limitations
2. Galera Architecture: strengths and limitations
3. Deployment scenarios
4. Data migration
5. Read and write workloads (Optimistic/pessimistic locking)
6. WAN/Geographical replication
7. Schema changes
8. Management and monitoring …

upload on 2014.12 [ten important tips of MySQL database design for better performance] Download this PDF

Installing Apache2 With PHP5 And MySQL Support On Fedora 21 (LAMP)

LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on a Fedora 21 server with PHP5 support (mod_php) and MySQL support.

There are few easy ticks to see what is stuck inside MySQL instance. All these techniques will not give you whole picture, but might help to find queries that block performance. Let’s start from what exactly doing your MySQL server right now.

Which queries are running now?

This will give you an idea what’s running right now so you can find long running queries which slowing down MySQL and/or causing replication lag:

mysql -e "SHOW PROCESSLIST" | grep -v -i "sleep"

It is more convenient than just run “SHOW PROCESSLIST” as it’s hiding all connected threads in “Sleep” state so you’ll get a clean output. Also you can get same output but updating each second:

watch -n1 'mysql -e "SHOW FULL PROCESSLIST" | grep -v -i "Sleep"'

What to look for? This is complex output but you can start with Time and State columns. When you see a query running for more …

When I talk about troubleshooting I like to repeat: "Don't grant database access to everybody!" This can sound a bit weird having one can give very limited read-only access.

But only if ignore the fact what even minimal privileges in MySQL allows to change session variables, including those which control server resources. My favorite example is "Kill MySQL server with join_buffer_size". But before version 5.7 I could only recommend this, but not demonstrate. Now, with help of memory summary tables in Performance Schema, I can show how unprivileged user can let your server to use great amount of swap.

At first lets create a user account with minimal privileges and login.

$../client/mysql -ulj -h127.0.0.1 -P13001
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 5.7.6-m16-debug-log Source distribution

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