This isn’t really a feature we should brag about, because it’s a bug that took us a while to figure out, but we believe in sharing the bad as well as the good. There’s a lot to learn from TCP reassembly and protocol reverse engineering!

We received a request from a customer to help track down the user that was sending some queries to their database. Normally we can find this information easily: the user is one of the properties of query samples, and we can just click on a sample and see it. But for this particular customer, the user was always unknown_user.

This means we weren’t able to figure out what database user was issuing the query. Normally there are two ways we can figure out what the user is:

1. We see the connection handshake and capture the username from there.
2. We see a COM_CHANGE_USER packet and capture it from that (rare).

Our theory was that …

The MySQL 5.7.7 JSON lab release has been getting a lot of attention. At a recent conference, I was cornered by a developer who wanted to jump in with both feet by running this release on his laptop on the flight home. However the developer was not sure how to begin.

1. Down load the MySQL JSON release from http://labs.mysql.com/. You will get the choice of a Linux binary or source code. Please grab the binary if you are using Linux and un-gzip/tar the download.

2. Shut down the current running version of MySQL. I was lucky in this case that the developer was using a recent copy of Ubuntu.

3. Change directory to the ~/Downloads/mysql-5.7.7-labs-json-linux-el6-x86_64 directory.

4. sudo ./bin/mysqld_safe –user=mysql&

5. ./bin/mysql -u root -p, then provde the …

It is not uncommon that developers, network/system administrators, or DevOps folks with general backgrounds, find themselves in a DBA role at some point in their career. So, what does a DBA do? In the previous post, we covered monitoring and trending practices, as well as some popular tools that you might find handy in your day to day work. 

We’ll continue this blog series with another basic but crucial DBA responsibility - taking backups of your data. Backup and restore is one of the most important aspects of database administration. If a database crashed and there was no way to recovery it, any resulting data loss might lead to devasting results to a business. One could argue that you can protect against crashes by replicating to multiple servers or data centers. But if it is an application error that propagates to all …

Ever since MySQL replication has existed, people have dreamed of a good solution to automatically split read from write operations, sending the writes to the MySQL master and load balancing the reads over a set of MySQL slaves. While if at first it seems easy to solve, the reality is far more complex.

First, the tool needs to make sure it parses and analyses correctly all the forms of SQL MySQL supports in order to sort writes from reads, something that is not as easy as it seems. Second, it needs to take into account if a session is in a transaction or not.

While in a transaction, the default transaction isolation level in InnoDB, Repeatable-read, and the MVCC framework insure that you’ll get a consistent view for the duration of the transaction. That means all statements executed inside a transaction must run on the master but, when the transaction commits or rollbacks, the following select statements on the session can be again …

For the majority of us who have grown accustomed to a Windows environment over the years, Linux can seem like another world. In essence, Linux is a free open-source operating system that has gained increasing popularity since its release in 1991. Linux is based on the whole Unix ecosystem of operating systems that grew out of Bell Laboratories in the early 1970s. Linux has been around for almost 25 years and grew immensely in the late 1990s and early 2000s when it became associated with the LAMP web development stack; Linux stands for the ‘L’ in the acronym of popular tools, along with Apache, MySQL, and PHP/Perl/Python.

The main difference that …

Im using the version 3.2 and does not work :-(
The installation stops without any error:

Step 1 of 9 : Database Software…
Installing Database Software…
Retrieving MySQL Database 5.6 …
[root@barbara orcl]#

What im missing?

When a user signs up for online backup service for MySQL we allocate two gigabytes of free disk space in our storage. It’s convenient for small databases. We manage the storage, no additional hardware is needed from the user. What if the database is large enough so 2 gigabytes is not enough?

TwinDB allows to backup MySQL to your own storage servers. The storage will be visible in TwinDB console, the dispatcher will set it as a destination server when scheduling backup jobs and will enforce retention policy.

But the biggest benefit of having your own storage server in TwinDB is that backup copies never leave your data center. The agents are still managed by TwinDB dispatcher, but when XtraBackup streams a backup copy it’s encrypted and piped over ssh to your server. That increases security of the solution – your data flow is under your control. Besides, no large amounts of data are transferred to the cloud.

The …

This Log Buffer edition transcends beyond ordinary and loop in few of the very good blog posts from Oracle, SQL Server and MySQL.

Oracle:

• Variable selection also known as feature or attribute selection is an important technique for data mining and predictive analytics.
• The Oracle Utilities SDK V4.3.0.0.2 has been released and is available from My Oracle Support for download.
• This article provides a high level list of the new features that exist in HFM 11.1.2.4 and details the changes/differences between HFM 11.1.2.4 and previous releases.
• In recent …

Look here:

MySQL 5.6 リファレンスマニュアル (含むMySQL Cluster 7.3-7.4マニュアル)
 http://dev.mysql.com/doc/refman/5.6/ja/index.html
MySQL Enterprise Monitor 3.0.18 マニュアル
 http://dev.mysql.com/doc/mysql-monitor/3.0/ja/index.html
MySQL Enterprise Backup ユーザーズガイド (バージョン 3.11.1)
 http://dev.mysql.com/doc/mysql-enterprise-backup/3.11/ja/index.html

If you cannot read this, it's because your Japanese isn't any better than mine. :-)

Jokes aside, as of June 4, 2015, some of the MySQL documentation is available in Japanese now. The biggest book that was translated is the MySQL 5.6 Manual, thousands of pages. The other books, …

VividCortex’s network traffic analyzer tool for MongoDB is an easy-to-use, non-intrusive way to gain insight into your server’s activity. Built for MongoDB servers running on Linux operating systems, it will help you understand your query workload.

This commandline tool captures TCP traffic on your server and decodes the protocol. It decodes and times queries, and outputs them in a standard log format. You can use standard log analysis tools such as Percona Toolkit’s pt-query-digest to analyze the output and build insight into queries and server performance.

The tool is built on VividCortex’s advanced network traffic capture technology and is also a safe way to assess how VividCortex’s agents will behave on your systems. It is a thin wrapper around our TCP and MongoDB decoding libraries. It does nothing but decode and print, and makes no attempt to communicate with the Internet or anything else. Simple, secure, and smart. …