Hot on the heals of last week's release we have released version 0.2.0 alpha of libAttachSQL.  For those who have missed my previous blog posts, libAttachSQL is a lightweight C connector for MySQL servers I'm creating with HP's Advanced Technology Group.  It has an Apache 2 license so is good for linking with most Open Source licenses as well as commercial software projects.

Changes in this release:

• Added support for query result buffering
• Passive connect on first query is now asynchronous
• Improved memory handling
• Many documentation changes, including API examples
• Many other smaller fixes

For more information see the libAttachSQL documentation and the …

Reading the article published on MariaDB site about performance evaluation of MySQL 5.7 -vs- MariaDB 10.1 I've got a double feeling: from one side I have no any reason to have a doubt in obtained results, and from another side - my feeling says me there is something going odd.. But well, I don't have any attention to blame anybody (and sorry if you think so) -- my willing here is only to understand what is going on, why, and what are the challenges on the observed test workload(s). I'll cover here only my observations on the LinkBench workload as it was not yet enough tested and involving many questions around..

LinkBench Benchmark :

• developed by Facebook Team, so represents a true real life workload
• written in Java
• from the beginning since it creation was reported as …

Recently while working on geographical master slave replication we encountered an issue, where in peak hours replication slave lagging.

when we checked SHOW SLAVE STATUS value of Seconds_Behind_Master was jumping from 0 to a random high value, and then back to 0.

We also found this in the processlist of Master,

1366318 rpluser [IP Address]:15120  NULL  Binlog  Dump   9033    Writing to net  NULL

The status “Writing to net” means that MASTER is sending (or trying to send) data to SLAVE.

In a healthy replication, the status would be “Has sent all binlog to slave; waiting for binlog to be updated“.

It usually happens when MASTER-SLAVE geographically distributed in different data-center,network , and slow network.

Here limited network bandwidth was causing a problem , …

August 15, 2014 By Severalnines

We're looking for an energetic and talented web developer to join our small but agile web team. This position is full-time and pay is negotiable. The hours are flexible and work can be done remotely.

Severalnines is a self-funded startup with a dozen employees; headquartered in Stockholm, Sweden and with a globally distributed, home-office based team. We provide automation and management software for database clusters. Our ClusterControl product is the leading management application for database clusters and is used by thousands of companies.

We were founded in 2010 and launched our product that same year, so you’ll be …

Twice each year members of the global open-source community converge on London in November and Santa Clara in April to network with, and learn from, some of the world’s most experienced and accomplished system architects, developers and DBAs.

And now it’s time for YOU to give back to this diverse and growing MySQL community. The Call for Speakers for Percona Live London (Nov. 3-4) closes Aug. 17 and the deadline for submitting talks for the ever-growing Percona Live MySQL Conference and Expo (April 13-16, 2015) expires Nov. 9.

If you like putting things off until the last minute, then it’s time to get to work! Aug. 17 is just two days away and November will be here before you know it (think of how fast summer has gone by already).

…

We've all heard the hype.  MySQL 5.6 is packed with amazing new features that address all our database problems.  5.6 deals with replication and HA and performance and monitoring and security and features.  It just may cure cancer.

In fact it's been out for ages.  It went GA  …

Virtual servers for MySQL are popular but are they the answer? Should we be containing our instances instead. An Updated Performance Comparison of
Virtual Machines and Linux Containers is an interesting study of using containers over VMs by four brilliant folk from IBM Research in Austin. There are several benefits to containers that are detailed in the study.

So what is wrong with VMs? IBM has been using them since the 1970s. Well, VMs have a static number of virtual CPUs (vCPU) and a fixed amount of RAM that bound performance. And each vCPU can only use up to one real CPUs of clock cycles. Since each VM is a Linux process, resource management like the scheduler come into play.

Containers? They are built on the kernel namespaces. A container acts like its own little Linux box but …

So I ran across a situation today dealing with having to update a field but the user was unable to do so because of the related foreign key constraints.

This blog post with be a simple example showing a foreign key and how to update them if you have to do so.

First let us create a simple table and populate it with random data.

CREATE TABLE `table_w_code` (
`SOMECode` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`NameofCode` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (`SOMECode`)
) ENGINE=InnoDB ;


Now we will need another table that has a foreign key tied to our previous table.

[anothermysqldba]> CREATE TABLE `table_with_fk` (
`SOMEID` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`SOMECode` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`Somemorefields` varchar(150) COLLATE utf8_unicode_ci …

August 13, 2014 By Severalnines

New Webinar: Performance Tuning of HAProxy for Database Load Balancing

Date, Time & Registration: 

Tuesday, September 9th @10am CEST (Europe & MEA / Asia Pacific)

Register here

Tuesday, September 9th …

Actually, I found this error many times, while installing MySQL/Percona servers with MySQL Sandbox.

To resolve this issue, first, you have to make sure that, SSL is installed /update properly.

sudo apt-get update
sudo apt-get install libssl1.0.0 libssl-dev

After installing this you have to create appropriate link to make it work.

For 32 bit

cd /usr/lib/
sudo ln -s libssl.so.1.0.0 libssl.so.6
sudo ln -s libcrypto.so.1.0.0 libcrypto.so.6

For 64 bit:

cd /usr/lib/x86_64-linux-gnu
sudo ln -s libssl.so.1.0.0 libssl.so.6
sudo ln -s libcrypto.so.1.0.0 libcrypto.so.6

Normally this should work for CentOS and Debian too but If in Debian, it didn’t worked then do this.

sudo ln -s /usr/lib/x86_64-linux-gnu/libssl.so.1.0.0 /usr/lib/libssl.so.6
sudo ln -s /usr/lib/x86_64-linux-gnu/libcrypto.so.1.0.0 /usr/lib/libcrypto.so.6

I’m sure, it will work.

…