Weekly Snap: MySQL, Puppet & OpenLDAP tricks

16 – 20 May was filled with tips and tricks for MySQL, Puppet, OpenLDAP and thoughts on social networking usage.
To begin, Bernd discussed the MySQL concurrent read/write function. Unlike InnoDB which supports real ACID transaction administration, MyISAM nonetheless enables concurrent reading/writing. For this he recommends the concurrent_insert parameter which controls simultaneous access to a table, alongside the regular use of ‘optimise table’. Unfortunately, this may no longer work if the writing is activated by Binlogs as the database engine is “forced” into following the correct serial order to maintain its uniqueness in the Binlog.
Continuing on the topic of MySQL, Gunnar offered his tip to accelerate test imports. With the libeatmydata library, the fsync() function can be deactivated for certain applications. But he cautioned that it can lead to data loss and irreparable database damage when inappropriately implemented.
From databases to their directory services, Philip looked at OpenLDAP. He considered the purpose of directory services and the current version OpenLDAP 2.4 in terms of performance and functionality. Of note were two new features which enable greater replication: MirrorMode distributes LDAP servers across two locations, and enables data replication via two providers, while N-Way Multimaster allows the replication of multiple active masters, which can be combined in any number of ways and in turn possess slave servers.
Manuela shared the results of a study into the European use of email, Facebook, Twitter and other social media. She noted that 50% of all Europeans use both email and social networks, with Facebook the undisputed leader (Hyves in Holland being the exception). Also dubbed “multi-channel countries”, company fan pages are best received in Great Britain, Italy and Spain. In contrast, Germany, France and Holland tend more towards being“email countries”. The study includes consumer and decision maker surveys, and can be found at eCircle.
Finally, Christoph showed us how SSH key administration can be done with Puppet in 3 steps. First by creating an SSH class, then SSH keys for root registration and lastly SSH keys for user registration.