The latest from the MySQL community

In many write-intensive workloads Innodb/XtraDB storage engines you may see hidden and dangerous “debt” being accumulated – unpurged transaction “history” which if not kept in check over time will cause serve performance regression or will take all free space and cause an outage. Let’s talk about where it comes from and what can you do to avoid running into the trouble.

Technical Background: InnoDB is an MVCC engine which means it keeps multiple versions of the rows in the database, and when rows are deleted or updated they are not immediately removed from the database but kept for some time – until they can be removed. For a majority of OLTP workloads they can be removed seconds after the change actually took place. In some cases though they might need to be kept for a long period of time – if there are some old transactions running in the system that might still need to look at an old database state. As of …

Bloggers get connected to both the databases and their readers through their blogs. Bloggers act like a bridge here. Log Buffer extends this nexus through the Log Buffer Edition.

Oracle:

MS Sharepoint and Oracle APEX integration.

Just a couple of screenshots of sqlplus+rlwrap+cygwin+console.

Say “Big Data” One More Time (I dare you!)

Update OEM Harvester after 12.1.0.4 Upgrade

Insight in the …

October 17, 2014 By Severalnines

Integrating ClusterControl with a corporate LDAP directory is a common task for many IT organizations. In an earlier blog, we showed you how to integrate ClusterControl with OpenLDAP. In this post, we will show you how to integrate with FreeIPA and Windows Active Directory. 

How ClusterControl Performs LDAP Authentication

ClusterControl supports up to LDAPv3 protocol based on RFC2307. More details on this in the documentation.

When authenticating, ClusterControl will first bind to the directory tree server (LDAP …

At MySQL, replication usability is of utmost importance to us. Replication information has long been part of SHOW commands, SHOW SLAVE STATUS occupying a major chunk of it. The other sources of replication information being: SHOW MASTER STATUS,
SHOW BINLOG EVENTS,
SHOW RELAYLOG EVENTS,
SHOW VARIABLES,
SHOW STATUS,
…

At MySQL, replication usability is of utmost importance to us. Replication information has long been part of SHOW commands, SHOW SLAVE STATUS occupying a major chunk of it. The other sources of replication information being:

SHOW MASTER STATUS,
SHOW BINLOG EVENTS,
SHOW RELAYLOG EVENTS,
SHOW VARIABLES,
SHOW STATUS,
…

Multi-source replication for MySQL has been released as a part of 5.7.5-labs-preview
downloadable from labs.mysql.com. It is one among the several features that are
cooking in the replication technologies at MySQL.  (For a birds eye view of all
replication features introduced in 5.7 and labs, look  at the blog posts here and here.

Previously, we have introduced a preliminary multi-source feature labs preview. Based on the feed back from that labs release, we …

We have been asked several times by MySQL users about how to install multiple MySQL instances on a single host.
Typically, this is required when testing different MySQL versions or MySQL servers (MySQL server, Percona server and MariaDB server) while no available resources are available.
Sometimes, it is even required to install multiple MySQL instances on a single production server.

In this article, I'll go through the steps needed to install multiple MySQL instances on a single host (using the tar balls binaries) and how our popular tool MyEnv can make such process so easy.

Prepare MySQL environment

[root@centos-temp ~]# groupadd mysql
[root@centos-temp ~]# useradd -g mysql mysql
[root@centos-temp ~]# su - mysql
[mysql@centos-temp:~]$ mkdir ~/product
[mysql@centos-temp:~]$ mkdir ~/data
[mysql@centos-temp ~]$ cd /downloads
[mysql@centos-temp …

I recently had a client ask me how to use Percona Toolkit tools with an SSL connection to MySQL (MySQL-SSL). SSL connections aren’t widely used in MySQL due to most installations being within an internal network. Still, there are cases where you could be accessing MySQL over public internet or even over a public “private” network (ex: WAN between two colo datacenters). In order to keep packet sniffers at bay, the connection to MySQL should be encrypted.

If you are connecting to Amazon RDS from home or office (ie: not within the AWS network) you better be encrypted!

As there is already a MySQL Performance Blog post on how to setup MySQL SSL connections, we can skip that and dive right in.

As you probably know, the mysql client …

In a few weeks I’m presenting “Performance Benchmarking: Tips, Tricks, and Lessons Learned” at Percona Live London 2014 (November 3-4). I continue to learn lessons and improve my benchmarking capabilities, so the content is a full upgrade from my presentation at Percona Live Santa Clara in April 2013. Anyone interested in achieving and sustaining the best performance out of their software/hardware/application should attend.

Also, Tokutek is sponsoring so we’ll be available in the expo hall throughout the show.

If you are attending or in the area and want to learn more about …

In the new InnoDB lab release we support page sizes of 32k and 64k. This gives users even more choices on the page size, allowing you to further customize InnoDB for your particular workload.

There are some things worthy of note related to this new feature:

1. The extent size changes when the innodb_page_size is set 32k or 64k.
   The extent size is 2M for 32k page sizes, and 4M for 64k page sizes (the extent size is 1M for 4k, 8k, and 16k page sizes). If we do not enlarge the extent size then we will have too many extent headers on the allocation bitmap page, and the bitmap page will overflow.
2. The …