Databases
MySQL shutdown via service reporting ERROR
Working with MySQL 5.6 under CentOS 6.4 I came across the following problem with MySQL reporting it did not shutdown successfully. $ sudo su - $ service mysql stop Shutting down MySQL.
Read moreUpdating MySQL using official repositories
The announcement of the MySQL Yum repositories was a long overdue request on my wish list. While it was possible to find MySQL at http://public-yum.oracle.com/ it was not the GA version MySQL 5.
Read moreMySQL performance schema threads
A trap for those new to the MySQL Performance Schema is the expectation that thread_id in tables such as events_statements_current matches the id you find in the MySQL processlist. This is NOT TRUE.
Read moreWhat causes LOST_EVENTS error in the MySQL binary log?
Using MySQL 5.6.13 under CentOS 6.4, I had a replication failure on one master/slave topology because the master binary log had the following entry that was intentionally written by the MySQL server.
Read moreMySQL/NoSQL/Cloud Conference Latin America
Last week I was a guest speaker at the second annual MySQL/NoSQL/Cloud Conference held in Buenos Aires, Argentina. Thanks to Santiago Lertora from Binlogic who has taken on the responsibility of organizing a event for the MySQL community in South America.
Read moreAn unexplained connection experience
The “Too many connections” problem is a common issue with applications using excessive permissions (and those that grant said global permissions). MySQL will always grant a user with SUPER privileges access to a DB to investigate the problem with a SHOW PROCESSLIST and where you can check the limits.
Read moreA friday MongoDB funny
I had to laugh (just a bit) at this on the exhibitor floor at Oracle Open World 2013. There was a large MongoDB presence at the Slot 301 . There are a few reasons.
Read moreAdditional DB objects in AWS RDS
To expand on Jervin’s Default RDS Account Privileges , RDS for MySQL provides a number of routines and triggers defined the the ‘mysql’ meta schema. These help in various tasks because the SUPER privilege is not provided.
Read moreMySQL MHA and Perl pathing
I am certainly not a knowledgeable Perl person, however I recently ran into the error Can’t locate MHA/MasterMonitor.pm on Red Hat 6.x. I have installed MySQL MHA on various systems before without any issues.
Read moreCloning MySQL 5.6 instances
A tip for all those cloud users that like cloning database servers (as reported in my book Effective MySQL – Replication Techniques in Depth ). Starting with MySQL 5.6, MySQL instances have a UUID .
Read moreUnnecessary 3am (emergency) call
Help, the database is on fire. Well, it probably is but the solution may also be easy. Here are a few steps for the part-time MySQL DBA/sysadmin/developer. Total time to address this solution was 2 minutes, the inability to not go back to sleep, not priceless.
Read moreIdentifying empty tables in MySQL
The following simple INFORMATION_SCHEMA statement will identify and also verify tables that have no rows. These may be candidate tables to remove from your data model. mysql --defaults-file=.my.cnf -N -e "
Read moreA simple FAILED SQL statement breaks MySQL 5.6 replication
I setup 6 shiny new MySQL 5.6.13 MySQL servers, ready for testing and production deployment tomorrow. I found that the New Relic MySQL Monitoring was throwing the following error. [2013-08-08 03:53:33 +0000] com.
Read moreDP#8 The disadvantages of row at a time processing
It can be hard for software engineers to understand the following principle, however it is very important for improving performance and obtaining immediate scalability options. The principle is “Do Less Work”.
Read more