A few days ago my colleague asked me to help him figure out why his Wordpress website was running so slow. Everything seemed fine, the CPU was not busy, the memory was not used much. It was not the network issue because its ping time was very fast. The MySQL database was not slow either. So it was hard for me to debug.

The site returned 504 error initially, but it sometimes could load the page (after a long wait). I checked the Nginx error log and found that the upstream connection was not responded. So it must be something wrong with the PHP code.

I tried many ways which I found on the internet but no success. Most of them were about increasing the timeout or the execution time. By doing that, the page could load but it was still super slow (it loaded in > 1min).

When I sat quietly for a while to think, I realized that plugins could be the issue. There could not be any reason a Wordpress could be that slow unless …

We have been told many times that modifying live database should be done with extreme care, we should always make a backup before doing something big to the database. However, there are countless stories on the Internet about losing data due to various reason, one of them is forgetting to create a backup (Gitlab is an example: https://about.gitlab.com/2017/02/01/gitlab-dot-com-database-incident/). I was facing the same issue when upgrading MySQL server to a new version. Luckily I was able to restore most of the data but it was still a very good lesson for me. One of lesson I learned is how we could restore the data from the *.ibd and *.frm file.

The database I worked with had many tables. There were about 5 of them using MyISAM engine while others were using InnoDB engine. I was asked to upgrade the entire the …

Version 0.3.0 of dbdeployer has gained the ability of deploying multiple sandboxes concurrently. Whenever we deploy a group of sandboxes (replication, multiple) we can use the --concurrent flag, telling dbdeployer that it should run operations concurrently.

What happens when a single sandbox gets deployed? There are six sets of operations:

1. Create the sandbox directory and write down its scripts;
2. Run the initialisation script;
3. Start the database server;
4. Run the pre-grants SQL commands (if any;)
5. Load the grants;
6. Run the post-grants SQL commands (if any;)

When several …

Amazon Web Services (AWS) is a cloud platform that offers a wide variety of services including computing power, database storage, content delivery and other functionality that targets businesses of all sizes. One of their database solutions includes the Amazon Relational Database Service. Amazon RDS includes a number of popular RDBMSes, including Amazon Aurora, PostgreSQL, MySQL, MariaDB, Oracle, and Microsoft SQL Server, as well as tools to manage your databases and monitor their performance.

Despite the wide range of metrics available within the Amazon RDS console, there are some very good reasons for using your own monitoring tool(s) instead or in addition to those offered by Amazon RDS. For example, familiarity with your own tool(s) or access to features that Amazon RDS does not provide would constitute two persuasive reasons for employing a local tool.

With traditional software monitoring platforms such as Monyog still enjoying …

In this post, we’ll address how MaxScale monitors servers. We saw in the

We saw in the previous post how we could deal with high availability (HA) and read-write split using MaxScale.

If you remember from the previous post, we used this section to monitor replication:

[Replication Monitor]
type=monitor
module=mysqlmon
servers=percona1, percona2, percona3
user=maxscale
passwd=264D375EC77998F13F4D0EC739AABAD4
monitor_interval=1000
script=/usr/local/bin/failover.sh
events=master_down

But what are we monitoring? We are monitoring the assignment of master and slave roles inside MaxScale according to the actual replication tree in the cluster using …

The CVE-2015-0204 FREAK SSL vulnerability abuses intentionally weak “EXPORT” ciphers which could be used to perform a transparent Man In The Middle attack. (We seem to be continually bombarded with not only SSL vulnerabilities but the need to name vulnerabilities with increasing odd names.)

Is your server vulnerable?

This can be tested using the following GIST

If the result is 0; the server is not providing the EXPORT cipher; and as such is not vulnerable.

Is your client vulnerable?

Point your client to https://oneiroi.co.uk:4443/test if this returns “Vulnerable” then the client is vulnerable, if you find a connection error your client should not be vulnerable for example:

root@host:/tmp$ openssl …

Configuring MySQL Server, with the dozens of options available, has always been perceived as a bit of a black art. In MySQL Database 5.6, configuring your MySQL server for optimal performance is easier than ever before.

In the MySQL for Database Administrators course you can learn more.

MySQL 5.6 is configured to work faster out of the box in a wide range of installation scenarios and it is easier than ever to set up the server by adjusting only a small number of settings which cause others to be set. In addition, you get a new default my.cnf file with instructions guiding your through adjusting key settings. The …

Recently a several releases of MySQL Server were announced to our mailing lists. Do not miss following news:

• Announced releases:
  • Jun 6, 2013 - MySQL Server 5.1.70
  • Jun 6, 2013 - MySQL Server 5.5.32
  • Jun 6, 2013 - MySQL Server 5.6.12
• More can be found at: …

You might have seen my attempts at testing MySQL as a Key Value Store (KVS) (here and here), i.e. used like MongoDB, and I have had some comments to those. Above all, many wanted to know the details of my test environment. To be honest, this started off as a very simple thing, but it turned out a bigger than I thought, so I guess its reasonable to give some background. I apologize for not giving you this background before, but as I said, my initial intention was to just run bog standard MongoDB versus MySQL and see what happened.BackgroundHere at Recorded Future, when I joined about 2 …

The MySQL developer tools team announces the availability of version 5.2.41 of the MySQL Workbench GUI tool. This version has significant improvements in several parts of the tool and also includes the new Migration Wizard plugin.

The new Migration Wizard presents an easy to use GUI for migrating databases from third party products to MySQL. In this initial release, support for Microsoft SQL Server is included, in addition to other products that support ODBC, such as PostgreSQL.

Other improvements include:

• More than 100 bug fixes
• Code completion in the SQL Editor (beta)
• Better handling of schema synchronization in modeling

For a full list of issues fixed in this release, see  http://dev.mysql.com/doc/workbench/en/changes-5.2.x.html

Please get your copy from our Downloads …